A method and system for breeding a new low salinity breeding strain of macrobrachium rosenbergii based on blup family selection

Abstract

The present application relates to the technical field of aquatic genetic breeding, and particularly relates to a breeding method and system for breeding a new low-salinity breeding line of Macrobrachium rosenbergii based on BLUP family selection. The present application sets up ion compensation paths and non-compensation paths in parallel salinity steps for the same family at a metamorphosis key window, obtains metamorphosis completion rate and recovery survival rate at each salinity, determines ion compensation critical salinity and non-compensation critical salinity, and constructs an ion compensation dependency coefficient. Environmental deviation is calculated in combination with water quality and pathogen and other environmental indexes, and records are weighted and gated, BLUP genetic evaluation is implemented based on weighted data, a selection index considering target salinity out-pool rate, non-compensation critical salinity and dependency coefficient is constructed, and a new line capable of being stably bred at a target low salinity and having low ion compensation dependency is obtained through iterative selection under inbreeding constraint, so that cost reduction and emission reduction and large-scale popularization are realized.

Description

Technical Field

[0001] This invention relates to the field of aquatic genetic breeding technology, and in particular to a method and system for breeding new low-salinity breeding strains of giant freshwater prawns based on BLUP family selection. Background Technology

[0002] The giant freshwater prawn (Macrobrachium rosenbergii) is characterized by its rapid growth, large size, strong adaptability, and high economic value. Currently, giant freshwater prawn seed production typically requires larval development and metamorphosis to occur in brackish water conditions with a certain salinity. Producers often use artificially prepared seawater or saline-based water systems to meet the osmotic pressure and ion balance requirements for seedling cultivation. However, traditional high-salinity seedling cultivation methods present two significant problems: firstly, the cost of artificial seawater preparation and water exchange is high; secondly, the saline discharge of seedling wastewater poses a risk of salinization to surrounding water bodies and soil, continuously increasing environmental pressure. Under the background of green aquaculture and emission reduction policies, reducing seedling salinity and minimizing salt consumption and saline wastewater discharge have become urgent technological directions for the giant freshwater prawn breeding and seedling industry.

[0003] To standardize the breeding process and improve the survival rate of giant freshwater prawns, existing technologies have developed several process schemes focusing on broodstock selection, overwintering rearing, larval rearing, and desalination for seedling emergence. For example, Chinese patent document (CN104823883A) discloses a method for breeding giant freshwater prawn seedlings. This method involves gradually desalinating the larvae after they have reached a certain age and a high proportion have metamorphosed into juveniles. This is achieved within several days by lowering the pond water level and gradually injecting fresh water, ultimately reducing the salinity to a low level for seedling emergence or temporary rearing. The technological contribution of this type of scheme mainly lies in the standardization of the seedling rearing process and the improvement of seedling emergence and size uniformity through desalination. However, its core remains a production process improvement, focusing on enhancing the controllability of the breeding process and seedling quality under given broodstock conditions. It lacks a systematic breeding design for the genetic improvement and stable transmission of low-salinity breeding ability.

[0004] Furthermore, to improve the adaptability of larvae to freshwater or low-salinity environments, some existing technologies emphasize optimizing ion balance through compensation of key inorganic ions. For example, Chinese patent literature (CN110419477B) proposes detecting the potassium and calcium ion content in the water during the preparation stage of the seedling culture pond, and adjusting the potassium and calcium ion concentrations to a specific range (e.g., 140–160 mg / L) using potassium chloride and calcium chloride. This is combined with water temperature rise curves, feeding strategies, and daily aeration / sterilization management to improve survival rate and freshwater adaptability. This type of technology demonstrates the importance of ion compensation, water quality management, and feed regulation in improving seedling stability under low salinity conditions. However, its essence remains the engineered regulation of environmental conditions: significant differences in background ion levels in water sources across different regions, variations in the intensity and ratio of ion compensation, and significant fluctuations in microbial load can lead to noticeable fluctuations in the performance of the same batch of seedlings under different scenarios. Furthermore, this type of process does not address the crucial question in breeding evaluation: whether the good performance under ion compensation conditions stems from genetic salt tolerance or from dependence on external ion compensation.

[0005] Alongside seedling production, family selection and genetic evaluation methods have been widely adopted in the genetic improvement of giant freshwater prawns and other aquatic animals. Chinese patent document (CN102845342A) discloses a method for the retention and mating of fish and shrimp breeding populations. This method uses a selection index as its core, completing family-level selection and parent pairing under the constraint of a limited common-parent coefficient. Within the retained families, male and female parents are further selected based on individual selection indices to construct the next generation of breeding populations, thereby improving the genetic progress of target traits. This type of technology embodies a universal breeding framework based on the family as the basic unit, combining index selection and inbreeding control, and can serve the improvement of various economic traits such as growth and survival. However, when facing the highly environmentally sensitive goal of low-salinity breeding, relying solely on conventional family testing and index selection still faces practical difficulties: low-salinity breeding-related phenotypes (such as metamorphosis completion rate, pond discharge rate, and survival rate after stress) are highly affected by the environment, especially by the process of salinity decline, ion background, ammonia nitrogen / nitrite levels, pathogen loads such as Vibrio, and management consistency, resulting in significant phenotypic noise and enhanced common environmental effects, thereby weakening the accuracy of genetic assessment; at the same time, if the phenotypic gains brought by ion compensation are not stripped and quantified, the breeding process may inadvertently select populations that are highly dependent on external ion compensation, so that new lines still require high salt / ion input in actual promotion, and cannot truly achieve the goal of cost reduction and emission reduction.

[0006] Therefore, the existing technologies have at least the following shortcomings: (1) Existing low-salt seedling technologies focus on desalination processes, water quality management, and ion compensation, lacking a reproducible, quantifiable, and heritable method for constructing low-salt breeding phenotypes that is closely coupled with genetic selection, making it difficult to promote low-salt breeding ability as a stable breeding goal. (2) Although existing family selection / index selection methods can achieve genetic progress under the constraint of common parent coefficients, in the highly environmentally sensitive scenario of low-salt breeding, if there is a lack of systematic gating and quantitative correction of factors such as salinity gradient, ion compensation, and environmental deviation, problems such as incomparable test results across batches, large deviations in breeding value estimation, and insufficient selection stability are likely to occur. (3) Especially in production practice, ion compensation-survival improvement is often significant under low-salt conditions, but existing technologies have not established a breeding evaluation mechanism that can distinguish between genetic low-salt tolerance and dependence on external ion compensation, making it difficult to achieve the dual goals of stable low-salt breeding and reduced external salt / ion input in the cultivation of new strains.

[0007] In summary, there is an urgent need for a new strain breeding technology for low-salinity breeding of giant freshwater prawns. This technology should be able to construct genetic evaluation indicators that better meet the industry's needs for cost reduction and emission reduction under standardized and reproducible low-salinity phenotypic determination procedures, and organically combine them with BLUP family genetic assessment, selection index, and inbreeding restraint mating strategies, thereby improving the breeding efficiency, stability, and adaptability of new low-salinity breeding strains. Summary of the Invention

[0008] The technical objective of this invention is to address the problems of traditional giant freshwater prawn (Macrobrachium rosenbergii) breeding relying on high salinity and external salt / ion compensation, resulting in high seedling costs and significant pressure from saline wastewater discharge, as well as the difficulty in distinguishing between genetic low-salinity tolerance and environmental compensation effects through conventional family breeding. This invention provides a method and system for cultivating new low-salinity breeding strains of giant freshwater prawns based on BLUP family breeding. By combining dual-path salinity gradient determination, ion compensation dependence evaluation, environmental deviation gating weighting, BLUP genetic assessment, and inbreeding constraint mating, the invention achieves simultaneous breeding of stable low-salinity breeding ability and low ion compensation dependence.

[0009] Firstly, in order to achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A method for cultivating a new low-salinity breeding strain of giant freshwater prawn based on BLUP family selection includes the following steps:

[0011] S1. Select healthy parent shrimp from the basic population of giant freshwater prawns, construct full-sib families and / or half-sib families and establish pedigree information;

[0012] S2. Set up ion compensation path and non-compensation path in parallel for the same family during the metamorphosis critical window to obtain the metamorphosis completion rate and recovery survival rate step by step.

[0013] S3. Determine the minimum salinity that satisfies the preset metamorphosis completion rate threshold and recovery survival rate threshold under the two paths respectively, obtain the critical salinity for ion compensation and the critical salinity for non-compensation, and construct the ion compensation dependence coefficient.

[0014] S4. Collect water quality and pathogen environmental indicators, calculate environmental deviation, and weight, deweight, or remove the measurement records accordingly.

[0015] S5. Based on pedigree information and weighted measurement data, implement the best linear unbiased prediction BLUP genetic assessment and construct a selection index that takes into account the target salinity discharge rate, uncompensated critical salinity and ion compensation dependence coefficient.

[0016] S6. Based on the selection results, crossbreed and iteratively select and breed under the constraints of the common parentage coefficient or inbreeding coefficient to form a breeding population of giant freshwater prawns that can stably complete seedling cultivation under the target salinity conditions and has low dependence on ion compensation.

[0017] As a further improvement, in step S1, the basic population is a core breeding population of giant freshwater prawns that has been continuously propagated and has a breeding record; the healthy broodstock shrimp meet the requirements of having no obvious damage to their body surface, intact appendages, normal feeding, normal gonadal development, and being negative for pathogens or having a detection threshold below the preset threshold.

[0018] And / or, in step S1, nested mating or factor mating is used to construct families; when nested mating is used, each male shrimp is paired with 2 to 3 female shrimps, and the family coefficient is no less than 30 per generation.

[0019] As a further improvement, in step S2, the ion compensation path is a reference path that applies ion compensation while adjusting salinity so that at least one key ion among potassium ions, calcium ions and magnesium ions does not constitute a limitation; the non-compensation path is a measurement path that adjusts salinity only without compensating for the ratio of potassium ions, calcium ions and magnesium ions.

[0020] And / or, in step S2, the ion compensation path and the non-compensation path use the same batch of larvae from the same family, and maintain consistent water temperature, oxygenation, feeding, sewage discharge, water exchange, and daily disinfection management conditions; the two path measurement units are physically isolated from each other to avoid crosstalk during ion addition;

[0021] And / or, in step S2, the metamorphosis critical window meets any of the following conditions: the proportion of juvenile shrimp in the nursery unit reaches 50% to 90%; or dense molting occurs and the number of juvenile shrimp in different morphological forms increases by no less than 30% compared to the previous day in two consecutive daily inspections;

[0022] And / or, in step S2, the salinity gradient is determined from an initial salinity of 8‰ to 10‰, decreasing in single-level salinity reduction increments of 0.3‰ to 0.8‰ and holding for 0.5 hours to 2 hours per level, to a final salinity of 4.5‰ to 6.5‰; after holding at the low-salinity critical level for 24 to 72 hours, the salinity is restored to the initial salinity, and observation continues for 12 to 48 hours to obtain the recovery survival rate.

[0023] As a further improvement, in step S3, the threshold for the metamorphosis completion rate is 80% to 90%, and the threshold for the recovery survival rate is 85% to 95%; the ion compensation dependence coefficient is the positive part of the difference between the non-compensated critical salinity and the ion-compensated critical salinity, used to characterize the degree of dependence of the family on ion compensation.

[0024] And / or, in step S4, the environmental indicators include at least temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite and Vibrio count; the environmental deviation is obtained by weighted synthesis of the standardized deviation of each environmental indicator relative to the baseline of the same batch, and the larger the environmental deviation, the smaller the weight of the corresponding measurement record;

[0025] When the Vibrio count, ammonia nitrogen concentration, or nitrite concentration corresponding to the measurement record reaches the corresponding preset threshold, or when a power outage, oxygenation failure, mechanical damage, or abnormal ion dosing event occurs, the measurement record will be downweighted or removed; when the abnormal event affects both the ion compensation path and the non-compensation path, the records corresponding to both paths will be downweighted or removed simultaneously.

[0026] As a further improvement, in step S5, the BLUP genetic assessment adopts a mixed linear model, which includes at least batch effect and seedling unit effect as fixed effects, and additive genetic effect and common environmental effect as random effects; wherein, the weights of the measurement records are used for weighted BLUP solution.

[0027] And / or, in step S5, the selection index increases with the breeding value of the effluent rate or survival rate at the target salinity, and decreases with the breeding value of the non-compensated critical salinity and the breeding value of the ion compensation dependence coefficient; the target salinity is 6‰ to 10‰.

[0028] As a further improvement, in step S6, the mating scheme satisfies that the inbreeding coefficient is lower than the preset upper limit of inbreeding and the effective population size is not lower than the preset lower limit; steps S1 to S6 are repeated for at least 3 generations to obtain the next generation of breeding population and its low-salt breeding stability is continuously evaluated.

[0029] Secondly, the present invention also provides a breeding system for a new low-salinity breeding strain of giant freshwater prawn based on BLUP family selection, used to implement the method described above, the system comprising:

[0030] The parent and pedigree management unit is used for parent shrimp registration, health check result entry, mating design generation, pedigree numbering, pedigree information storage and tracing.

[0031] The seedling and dual-path measurement execution unit is used to set up measurement units with ion compensation paths and non-compensation paths for the same family.

[0032] The salinity step control unit is used to control the salinity to gradually decrease from the initial salinity to the final salinity in single-stage reduction increments and durations, and to control the stress maintenance and recovery observation process.

[0033] The ion compensation and dosing unit is used to implement key ion compensation in the ion compensation path and record dosing information;

[0034] Water quality and pathogen monitoring unit, used to collect water quality and pathogen environmental indicators;

[0035] The data acquisition and calculation unit is used to collect phenotypic data, environmental data and measurement logs, and to calculate critical salinity, ion compensation dependence coefficient, environmental deviation and measurement record weight.

[0036] Genetic evaluation and selection decision unit, used to perform weighted BLUP genetic evaluation and calculate the selection index;

[0037] The mating and inbreeding constraint management unit is used to generate mating schemes and control inbreeding levels and effective population size.

[0038] As a further improvement, the seedling raising and dual-path measurement execution unit includes mutually isolated ion compensation measurement units and non-compensation measurement units, and the two types of measurement units are respectively equipped with constant temperature, oxygenation, feeding, sewage discharge and water exchange devices to maintain consistent seedling management conditions except for ion compensation measures.

[0039] And / or, the salinity step control unit includes a salinity sensor, a freshwater supply device, a brine supply device, a mixing and circulation device, and a controller; the controller is used to perform closed-loop control according to the set initial salinity, final salinity, single-stage salinity reduction range, duration of each stage, duration of stress, and duration of recovery observation;

[0040] And / or, the water quality and pathogen monitoring unit includes a detection module for detecting temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite and Vibrio count, and sends the detection results to the data acquisition and calculation unit for environmental deviation calculation and measurement record gating;

[0041] And / or, the data acquisition and calculation unit is configured to associate and store family number, measurement path, salinity level, metamorphosis completion rate, recovery survival rate, pond discharge rate, body length and weight, environmental indicators and abnormal events, and determine the ion-compensated critical salinity and the non-compensated critical salinity based on the same criterion.

[0042] And / or, the genetic assessment and selection decision unit is configured to generate a kinship matrix based on pedigree information, perform a weighted BLUP solution in combination with the weights of the measurement records, and output the breeding value, selection index and selection list of families and / or individuals;

[0043] And / or, the mating and inbreeding constraint management unit is configured to generate a mating matrix based on the kinship of selected families and individuals, and output a next-generation mating list when the inbreeding coefficient and effective population size meet preset conditions.

[0044] Thirdly, the present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the method described above.

[0045] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0046] This invention, by setting up ion-compensated and non-compensated paths for the same family and performing parallel salinity gradient measurements within the metamorphosis critical window, can obtain the metamorphosis completion rate, recovery survival rate, and critical salinity under both paths, thereby quantifying the family's dependence on ion compensation and avoiding the misselection of families highly dependent on added ions based solely on good performance under compensated conditions. Simultaneously, by collecting environmental indicators such as temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite, and Vibrio counts, calculating environmental deviations, and downweighting or removing abnormal measurement records, it can reduce the interference of water quality fluctuations, pathogen load, and management differences on low-salinity phenotypes, and improve the survival rate of strains. The comparability of data between different measurement units within the same batch and the accuracy of BLUP breeding value estimation; furthermore, by constructing a selection index that takes into account the target salinity discharge rate, non-compensated critical salinity, and ion compensation dependence coefficient, and conducting multi-generation iterative mating under the constraints of the common parentage coefficient or inbreeding coefficient, a new strain of giant freshwater prawn that can stably complete seedling cultivation under target low salinity conditions of 6‰ to 10‰, with high discharge rate, low ion compensation dependence, and sustainable improvement of genetic background can be obtained. This reduces the input of seedling salt and ion compensation from the source, lowers production costs and the risk of saline tailwater discharge, and improves the stability of large-scale promotion of low-salinity breeding technology. Attached Figure Description

[0047] Figure 1This is a schematic diagram of the overall structure of the new low-salinity breeding system for giant freshwater prawns based on BLUP family selection, as described in this invention.

[0048] Figure 2 This is a schematic diagram of the overall process of the cultivation method of the present invention.

[0049] Figure 3 This is a schematic diagram showing the data flow and control relationship of the dual-path salinity step phenotyping method of this invention.

[0050] Figure 4 This is a schematic diagram of the salinity gradient control and measurement parameters of the present invention.

[0051] Figure 5 This is a schematic diagram of the environmental deviation and recording weight gating of the present invention.

[0052] Figure 6 This is a schematic diagram of the weighted BLUP genetic evaluation and selection decision-making process of this invention.

[0053] Figure 7 The graph shows the metamorphosis completion rate of a typical family in the examples under both ion-compensated and non-compensated pathways, as a function of salinity.

[0054] Figure 8 The graph shows the recovery survival rate of a typical family in the examples under both ion compensation and non-compensation pathways, as a function of salinity.

[0055] Figure 9 The example shows a scatter plot of the non-compensated critical salinity and the ion compensation dependence coefficient of multiple systems.

[0056] Figure 10 This is a scatter plot comparing the effluent rates of the low-salt new strain group and the control group in each culture pond during the on-site acceptance test.

[0057] Figure 11 This is a comparison chart of the average body weight of the low-salt new strain group and the control group in a pond aquaculture performance comparison test.

[0058] Figure 12 This is a comparison chart of seedling survival rates under different salinity levels.

[0059] Figure 13 A comparison of the critical salinity for ion compensation and the critical salinity for non-compensated families in candidate families.

[0060] Figure 14 A comparison of the distribution of ion compensation dependence coefficients between the candidate families and the selected families.

[0061] Figure 15 Choose Pareto scatter plots for multi-objective selection.

[0062] Figure 16A comparative graph showing the effects of different selection rules on the average ion compensation dependence coefficient of the selected families.

[0063] Figure 17 A comparative chart showing the impact of different selection rules on the target salinity discharge rate of selected families. Detailed Implementation

[0064] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. It should be understood that the described embodiments are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention. All equivalent substitutions, parameter adjustments, or conventional combinations made by those skilled in the art without creative effort under the technical concept of the present invention should fall within the scope of protection of the present invention.

[0065] This invention relates to a method and system for breeding new low-salinity breeding strains of Giant River Prawns based on BLUP family selection. The core of this method lies in: instead of using only the low-salinity survival rate or hatching rate under a single pathway as the selection criterion, it involves conducting parallel salinity stepwise measurements on the same family within the metamorphosis critical window using both ion-compensated and non-compensated pathways. This yields the metamorphosis completion rate, recovery survival rate, and critical salinity under each pathway, and constructs an ion compensation dependence coefficient. Then, it calculates the environmental deviation by combining water quality and pathogen environmental indicators, and weights, deweights, or eliminates the measurement records. Subsequently, based on the weighted data, BLUP genetic evaluation is performed to construct a selection index that considers the target salinity hatching rate, non-compensated critical salinity, and ion compensation dependence coefficient. Finally, under inbreeding constraints, mating is conducted and iterative breeding is continuously performed to obtain a new Giant River Prawn strain that can stably complete seedling cultivation under target low salinity conditions and has low ion compensation dependence.

[0066] I. Terminology Explanation

[0067] To facilitate understanding of the present invention, the main terms used in the specific embodiments are explained below.

[0068] A pedigree is a population of offspring of the giant freshwater prawn (Macrobrachium rosenbergii) produced by a traceable mating combination of parents, including full-sib and half-sib families. Pedigrees are used to record kinship, perform low-salt phenotypic assays, and conduct BLUP genetic assessments.

[0069] The critical window of metamorphosis refers to the sensitive period during which giant freshwater prawn larvae undergo metamorphosis from the larval stage to the postlarval stage. Low-salinity gradient measurements performed during this period can more accurately reflect a family's ability to complete metamorphosis and recover survival in a low-salinity environment.

[0070] An ion compensation pathway refers to a reference assay pathway in which, in addition to adjusting salinity, key ion compensation is applied during salinity gradient determination to ensure that at least one of the key ions among potassium, calcium, and magnesium ions does not constitute a limiting factor. This pathway is used to obtain the low-salt performance of families when ion conditions are not the main limiting factor.

[0071] The non-compensation pathway refers to a measurement pathway in which only salinity is adjusted during salinity gradient determination, without compensation for the ratios of potassium, calcium, and magnesium ions. This pathway is used to reflect the low-salt reproductive capacity of families under low-input conditions with minimal salt and ion supplementation.

[0072] Metamorphosis completion rate refers to the proportion of individuals in a measurement unit that have reached the target metamorphosis stage at a certain salinity level out of the total number of individuals measured.

[0073] Recovery survival rate refers to the proportion of individuals that survive after being restored to the initial salinity or a relatively safe salinity level at a certain low salinity level for a certain period of time and then observed for a certain period of time.

[0074] The critical salinity for ion compensation refers to the lowest salinity that simultaneously satisfies the preset threshold for metamorphosis completion rate and the threshold for recovery survival rate in the ion compensation pathway.

[0075] Uncompensated critical salinity refers to the lowest salinity that simultaneously satisfies the preset abnormality completion rate threshold and recovery survival rate threshold in an uncompensated path.

[0076] The ion compensation dependence coefficient is an index used to characterize the degree to which a family's low-salt breeding performance depends on external ion compensation. The larger the coefficient, the weaker the family's ability to achieve the same low-salt performance under conditions without ion compensation, and the higher its dependence on ion compensation; the smaller the coefficient, the stronger the family's endogenous adaptation to low-salt conditions.

[0077] Environmental deviation refers to the overall degree of deviation of the measured environmental indicators, such as temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite, and Vibrio count, from the baseline state of the same batch.

[0078] BLUP, or Best Linear Unbiased Prediction, is used to estimate the breeding value of families and / or individuals based on pedigree information, phenotypic data, and environmental correction information.

[0079] II. System Structure

[0080] like Figure 1 As shown, the breeding system of the present invention includes a parent and family management unit 10, a seedling and dual-path measurement execution unit 20, a salinity gradient control unit 30, an ion compensation and dosing unit 40, a water quality and pathogen monitoring unit 50, a data acquisition and calculation unit 60, a genetic evaluation and selection decision unit 70, and a mating and inbreeding constraint management unit 80.

[0081] The parent and family management unit 10 is used for parent shrimp registration, entry of parent shrimp health examination results, mating design generation, family numbering, and storage and traceability of pedigree information. The family number can be formed by combining year, batch, mating combination number and family sequence number, so that each family can be traced in seedling breeding, testing, genetic evaluation and subsequent mating.

[0082] The seedling raising and dual-path measurement unit 20 is used to set up measurement units for ion-compensated and non-compensated paths for the same family. The two path measurement units are preferably spatially isolated to prevent crosstalk caused by ion additives from entering the non-compensated path. Both path measurement units are equipped with temperature control, aeration, feeding, wastewater discharge, and water exchange devices to ensure consistent seedling management conditions except for ion compensation measures.

[0083] The salinity gradient control unit 30 includes a salinity sensor, a freshwater supply device, a brine supply device, a mixing and circulation device, and a controller. The salinity gradient control unit 30 is used to perform closed-loop salinity reduction control according to preset initial salinity, final salinity, single-stage salinity reduction amplitude, and hold duration for each stage, and to perform stress hold and recovery observation processes at critical low-salinity levels. The operation of this unit is as follows: Figure 4 As shown.

[0084] The ion compensation and dosing unit 40 is only connected to or serves the ion compensation path, and is used to implement key ion compensation and record dosing information in the ion compensation path. It should be noted that this invention does not take a specific artificial seawater formulation or a specific ion concentration window as the core protected object, but rather uses the ion compensation path as a reference measurement condition to form a comparison with the non-compensation path and construct an ion compensation dependence coefficient.

[0085] The water quality and pathogen monitoring unit 50 is used to collect water quality and pathogen environmental indicators, including at least temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite, and Vibrio count. These indicators are sent to the data acquisition and calculation unit 60 to calculate environmental deviations and perform gating processing on the measurement records, such as... Figure 5 As shown.

[0086] The data acquisition and calculation unit 60 is used to collect and associate the family number, measurement path, salinity level, metamorphosis completion rate, recovery survival rate, pond discharge rate, body length and weight, environmental indicators and abnormal events; and to determine the critical salinity for ion compensation and the critical salinity for non-compensation based on the same criterion, and further calculate the ion compensation dependence coefficient, environmental deviation degree and recording weight.

[0087] The genetic evaluation and selection decision unit 70 is used to generate a kinship matrix based on pedigree information, perform a weighted BLUP solution by combining the weights of measurement records, and obtain breeding values ​​for traits such as target salinity discharge rate, non-compensated critical salinity, and ion compensation dependence coefficient for families and / or individuals, and further calculate the selection index. Its workflow is as follows: Figure 6 As shown.

[0088] The mating and inbreeding constraint management unit 80 is used to generate a mating matrix based on the kinship of selected families and individuals, and to control the inbreeding coefficient and effective population size, so that the next generation of breeding populations can maintain the necessary genetic diversity while achieving low-salt breeding genetic progress.

[0089] III. Specific Technical Route for Implementing the Method of the Invention

[0090] The method flow of the present invention is as follows: Figure 2 As shown, it includes steps S1 to S6. The following is in conjunction with... Figures 1 to 6 Each step is explained in detail.

[0091] Step S1, Establishment of lineage and pedigree

[0092] Healthy broodstock shrimp were selected from the basic population of giant freshwater prawns. The basic population can be a core breeding population that has been propagated for many years and has maintained breeding records, or a synthetic basic population introduced from multiple sources and then isolated and domesticated. Broodstock shrimp should meet the following conditions: no obvious damage to the body surface, intact appendages, normal feeding, normal swimming ability, and normal gonadal development. Preferably, they should have negative results or detection levels below the preset threshold for common pathogens.

[0093] In some implementations, nested mating is used to construct families, where each male shrimp is paired with 2 to 3 female shrimp to form several full-sib and half-sib structures. In other implementations, factor mating may be used to improve the efficiency of genetic parameter estimation. Each mating combination generates a unique family number and records the male parent number, female parent number, mating date, egg-carrying date, hatching date, larval introduction date, testing batch, and subsequent nursery unit number.

[0094] The above methods can establish a pedigree basis for BLUP genetic assessment and provide kinship information for subsequent inbreeding-restrained mating.

[0095] Step S2, Dual-path salinity step phenotyping

[0096] Step S2 is the key step that distinguishes this invention from conventional low-salt seedling cultivation techniques and conventional family selection methods. For example... Figure 3As shown, for the same family, parallel measurements were performed using an ion-compensated pathway and a non-compensated pathway within the metamorphosis critical window. Both pathways used larvae from the same batch, the same family, and the same developmental stage, and maintained consistent water temperature, dissolved oxygen, feeding, wastewater discharge, water exchange, and disinfection management conditions. The only difference was that the ion-compensated pathway applied critical ion compensation, while the non-compensated pathway did not perform critical ion ratio compensation.

[0097] The metamorphosis critical window can be triggered by any of the following conditions: the proportion of larvae in the nursery unit reaches 50% to 90%; or dense molting and an increase of at least 30% in the number of larvae in two consecutive daily inspections. Implementing low-salt stepwise measurements within the metamorphosis critical window can avoid premature low-salt stress leading to non-targeted mortality and can also more accurately evaluate the family's ability to complete metamorphosis and recover from low-salt conditions.

[0098] In practice, the salinity gradient determination can start with an initial salinity of 8‰ to 10‰, gradually decreasing to a final salinity of 4.5‰ to 6.5‰ in single-level reductions of 0.3‰ to 0.8‰ and maintaining each level for 0.5 hours to 2 hours. To cover the higher uncompensated critical salinity encountered in the examples, the initial salinity can be set to 9.5‰ in representative family determinations, with salinity levels sequentially being 9.5‰, 9.0‰, 8.5‰, 8.0‰, 7.5‰, 7.0‰, 6.5‰, and 6.0‰. After reaching a steady state at each salinity level, the abnormality completion rate is recorded. After maintaining at each low salinity level or a preset critical level for 24 to 72 hours, the salinity is restored to the initial level, and observation continues for 12 to 48 hours to obtain the recovery survival rate.

[0099] The abnormal completion rate can be calculated using the following formula:

[0100] ;

[0101] in, The salinity is abnormal completion rate at that time; The salinity is The number of individuals that reach the target metamorphosis stage; This represents the total number of individuals included in the statistics at this salinity level. To determine salinity.

[0102] The survival rate can be calculated using the following formula:

[0103] ;

[0104] in, The salinity is Survival rate after being maintained and observed under stress; To restore the number of surviving individuals after the observation period ended; This serves as the baseline for participation in recovery observation before the onset of low-salt stress; To determine salinity.

[0105] Figure 4 The execution logic of the salinity ladder is illustrated: the initial salinity is gradually decreased to the final salinity, and the phenotype is maintained and recorded after each level reaches steady state. Stress maintenance and recovery observations are completed at the critical low-salinity levels. Through this control method, the measurement conditions between different families and batches are comparable.

[0106] Step S3: Construct the critical salinity and ion compensation dependence coefficient.

[0107] Step S3 is used to convert the salinity response curve obtained in step S2 into a core phenotype that can be used for genetic evaluation. The metamorphosis completion rate threshold is set to 80% to 90%, and the recovery survival rate threshold is set to 85% to 95%. In some embodiments, the metamorphosis completion rate threshold is set to 80%, and the recovery survival rate threshold is set to 85%.

[0108] For each family and each measurement path, the lowest salinity that simultaneously satisfies both a metamorphosis completion rate and a recovery survival rate not lower than a preset threshold is identified. For ion-compensated paths, the obtained lowest salinity is the ion-compensated critical salinity; for non-compensated paths, the obtained lowest salinity is the non-compensated critical salinity.

[0109] The ion compensation dependence coefficient is determined by the following formula:

[0110] ;

[0111] in, The coefficient representing the ion compensation dependence. This is the non-compensated critical salinity. The critical salinity is compensated for by ions; This indicates taking the larger value between the number inside the parentheses and 0.

[0112] when A larger value indicates that while the family can reach a lower critical salinity under the ion compensation pathway, it requires a higher salinity to stabilize metamorphosis and recover under the non-compensation pathway, demonstrating a high dependence on ion compensation. When the value is close to 0, it indicates that the family's performance under the non-compensation pathway is close to that under the ion compensation pathway, and it has a stronger endogenous adaptation capacity to low salt.

[0113] Figure 13 The differences between the critical salinity for ion compensation and the critical salinity for non-compensation in candidate families are displayed in the form of bar charts, which intuitively reflects the degree of dependence of different families on ion compensation. Figure 9The distribution of uncompensated critical salinity and ion compensation dependence coefficient is further displayed in the form of a scatter plot, in which families located in the region of low uncompensated critical salinity and low ion compensation dependence coefficient are preferred candidate families.

[0114] Step S4, Environmental Deviation Gated Weighting

[0115] Low-salt breeding assays are easily affected by water quality fluctuations and pathogen loads. For example, short-term hypoxia, elevated ammonia nitrogen, elevated nitrite, or abnormally high Vibrio load can all lead to a decrease in metamorphosis completion rate and recovery survival rate. If these environmental anomalies are not identified, BLUP genetic assessment may misjudge environmental incidents as genetic differences.

[0116] Therefore, this invention collects environmental indicators including at least temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite, and Vibrio count, and calculates the environmental deviation. The environmental deviation can be determined by the following formula:

[0117] ;

[0118] in, Environmental deviation; For the number of environmental indicators; For the first Observed values ​​of environmental indicators; For the same batch The average value of each environmental indicator; For the same batch The standard deviation of each environmental indicator; For the first The weighting coefficients of each environmental indicator.

[0119] The weighting coefficients for each environmental indicator can be set based on pre-test data, historical measurement data, or expert experience. Preferably, the weighting coefficients for all environmental indicators satisfy the following: ； For indicators that have a significant impact on low-salt breeding assays, such as dissolved oxygen, ammonia nitrogen, nitrite, and Vibrio count, higher weights can be assigned; for indicators that have a smaller impact on short-term fluctuations, lower weights can be assigned.

[0120] The recording weights can be determined by the following formula:

[0121] ;

[0122] in, To determine the recording weight, the value ranges from 0 to 1; This is the sensitivity coefficient; Environmental deviation; This represents an exponential function. This is used to control the degree of weight reduction of the record weights based on environmental deviation. If If the deviation is large, even a slight increase in environmental deviation can significantly reduce the recording weight; if If the value is small, the recorded weights are not sensitive to changes in environmental deviation. In practical use, The value can be determined based on the correlation between environmental deviation and phenotypic stability in historical measurement data, or by selecting a value that has high consistency across batches of families through cross-validation.

[0123] The greater the environmental deviation, the lower the record weight. Records with Vibrio counts, ammonia nitrogen concentrations, or nitrite concentrations exceeding preset thresholds, or records of major abnormal events such as power outages, oxygenation failures, mechanical damage, or abnormal ion dosing, can be downgraded or removed. When an abnormal event simultaneously affects both ion compensation and non-compensation paths, the corresponding records for both paths are simultaneously downgraded or removed; when an abnormality only affects a single path, path-specific marking and processing are applied to the records for that path.

[0124] Figure 5 The process of calculating and recording environmental deviation and weighted gating is illustrated. This step reduces the interference of non-genetic factors on phenotypic determination and breeding value estimation, improving the comparability of cross-batch data.

[0125] Step S5: Weighted BLUP genetic assessment and selection index construction

[0126] Step S5 involves performing BLUP genetic assessment based on pedigree information and weighted measurement data. Target traits include at least the pond discharge rate or survival rate at the target salinity, the uncompensated critical salinity, and the ion compensation dependence coefficient. The target salinity can be between 6‰ and 10‰, but is preferably between 8‰ and 9‰ in actual production validation.

[0127] The mixed linear model can be expressed as:

[0128] ;

[0129] in, A vector of observations; Design a matrix for fixed effects; This is a fixed-effects vector, where fixed effects may include the measurement batch, the seedling unit, and the operational batch. Design a matrix for additive genetic effects; This represents the vector of additive genetic effects. Design a matrix for shared environmental effects; This represents the common environmental effect vector; This is the residual vector.

[0130] The weights obtained in step S4 Used for weighted BLUP solutions. One implementation assigns larger residual variances to records with smaller weights; another pre-processes the observations and design matrix with weights before solving. Both methods achieve the effect of minimizing the impact of environmental deviations on breeding value estimation.

[0131] The selection index can be constructed according to the following principles: the higher the effluent rate or survival rate at the target salinity, the larger the selection index; the lower the non-compensated critical salinity, the larger the selection index; the lower the ion compensation dependence coefficient, the larger the selection index. One expression of this is:

[0132] ;

[0133] in, To select the retention index; The breeding value representing the effluent rate or survival rate at the target salinity; This represents the breeding value for non-compensated critical salinity. This represents the breeding value for the ion compensation dependence coefficient. , , These are the selection weight coefficients corresponding to the target salinity effluent rate or survival rate, the non-compensated critical salinity, and the ion compensation dependence coefficient, respectively, and all are positive values. , , This is used to adjust the contribution of different breeding objectives to the selection index. Preferably, all three are positive values. If the production objective focuses on increasing the target salinity discharge rate, then it can be increased. If the production objective focuses on reducing the minimum fertile salinity under uncompensated conditions, then it can be increased. If the production objective focuses on reducing reliance on ion compensation, then it can improve... One preferred value is as follows: .

[0134] Figure 6 The weighted BLUP genetic evaluation and selection decision process is illustrated. Figure 15 This further illustrates the Pareto distribution relationship of multi-objective selection, where a smaller uncompensated critical salinity is better on the horizontal axis, and a larger target salinity effluent rate is better on the vertical axis. The size of the point represents the ion compensation dependence coefficient. Figure 15 It is evident that the present invention can select a family that combines low non-compensated critical salinity, high target salinity discharge rate, and low ion compensation dependence.

[0135] Step S6, Inbreeding-Constrained Mating and Multiple Generations of Iteration

[0136] Step S6, based on the selection results of step S5, formulates a mating plan under the constraints of the common parent coefficient or inbreeding coefficient. The mating plan should satisfy the condition that the inbreeding coefficient is lower than the preset upper limit of inbreeding and the effective population size is not lower than the preset lower limit. A minimum average common parent coefficient pairing strategy can be adopted to ensure that the selected families achieve low-salt breeding genetic progress while avoiding a rapid decline in genetic diversity.

[0137] In some implementations, steps S1 to S6 are repeated for at least three generations. Each generation includes family establishment, dual-path salinity gradient determination, environmental gating, BLUP genetic assessment, selection index ordination, and inbreeding constraint mating. The target salinity hatching rate and larval quality are then verified in a productive nursery pond. Through multiple generations of iteration, a new low-salinity breeding strain of *Macrobrachium rosenbergii* is obtained that stably completes seedling cultivation under target salinity conditions and exhibits low dependence on ion compensation.

[0138] The following combination Figures 7 to 17 The implementation effects of this invention are explained. It should be noted that the data involving pedigree numbers in the embodiments can be anonymized according to the actual breeding confidentiality requirements, but the measurement logic, statistical caliber, and expression of technical effects remain consistent.

[0139] Example 1: Seedling raising experiment at different salinities

[0140] This embodiment illustrates the feasibility of reducing salinity during Macrobrachium rosenbergii seedling rearing and provides an experimental basis for setting the target salinity in this invention. A small-scale low-salinity seedling rearing experiment was conducted using 160L plastic tanks, with the water temperature controlled at 31±0.5℃. For the first 7 days, the seedlings were fed Artemia nauplii, and from the 8th day onwards, they were fed Artemia nauplii and egg custard, four times daily. Routine wastewater discharge, water quality testing, and pathogen monitoring were also conducted.

[0141] The test results are as follows:

[0142]

[0143] As can be seen from the data in the table, under low or medium-low salinity conditions of 8‰, 7‰ and 10‰, the seedling survival rates were 83.33%, 83.33%, 84.44% and 78.89% respectively, none of which were lower than the 67.22% of the 15‰ control group. Figure 12 The relationship curves between different salinities and seedling survival rates illustrate the above trends, indicating that under reasonable water quality management and disease prevention conditions, there is room for reducing the salinity of giant freshwater prawn seedlings, and the cultivation of new low-salinity breeding strains has a realistic basis.

[0144] Example 2: Family dual-pathway salinity gradient determination and core phenotypic construction

[0145] This embodiment illustrates the implementation of steps S2 and S3 of the present invention. Twelve representative families from the 2022 batch were selected, numbered F22-01 to F22-12. Each family had an ion-compensated path and a non-compensated path, with a repeat measurement unit set up for each path. The water temperature, aeration, feeding, wastewater discharge, and water exchange conditions were consistent for both paths; the difference was that the ion-compensated path applied critical ion compensation, while the non-compensated path did not perform potassium, calcium, and magnesium ratio compensation.

[0146] To ensure that the critical salinity measurement range covers all families, this embodiment sets the salinity steps as 9.5‰, 9.0‰, 8.5‰, 8.0‰, 7.5‰, 7.0‰, 6.5‰, and 6.0‰. After each salinity level stabilizes, the metamorphosis completion rate is recorded, and stress maintenance and recovery observations are completed at the corresponding levels to calculate the recovery survival rate. Figure 7 This study demonstrates the variation in metamorphosis completion rate in typical family pedigrees within the low-salt-sensitive range of 8.5‰ to 6.0‰. Figure 8 This demonstrates the variation in recovery survival rates for the same family lineage within this timeframe. Figure 7 and Figure 8 It is evident that the low-dependency family F22-03 can still maintain good abnormality and recovery capabilities under the non-compensation pathway, while the high-dependency family F22-09 shows a significant decrease in performance as salinity decreases under the non-compensation pathway.

[0147] With an abnormality completion rate threshold of 80% and a recovery survival rate threshold of 85%, the following family-level results were obtained:

[0148]

[0149] As can be seen from the table, F22-10, F22-03, F22-06 and F22-04 have a combination of low uncompensated critical salinity, low ion compensation dependence coefficient and high target salinity effluent rate or survival rate, making them suitable as preferred families. Figure 9 The scatter plots of the uncompensated critical salinity and ion compensation dependence coefficients for each family are presented. Figure 13 This further demonstrates a side-by-side comparison between ion-compensated critical salinity and uncompensated critical salinity. Figure 14 The distribution of ion compensation dependence coefficients in the selected families is lower than that of the candidate families as a whole, indicating that the selection method of the present invention can reduce the population's dependence on ion compensation.

[0150] Comparative Example 1: Retention using only the ion compensation pathway

[0151] This comparative example did not include an uncompensated path; salinity gradient measurements were performed only under the ion-compensated path, and families were selected based on the principle that the lower the critical salinity for ion compensation, the better. According to this rule, F22-09, with its critical salinity for ion compensation reaching 6.5‰, might have been mistakenly judged as an excellent low-salinity family. However, as seen in Example 2, the uncompensated critical salinity of F22-09 was 8.0‰, the ion compensation dependence coefficient was 1.5‰, and the effluent or survival rate at the target salinity of 8.5‰ was only 74.2%. This indicates that the low-salinity performance of F22-09 mainly depends on ion compensation, and its stability is insufficient under conditions of minimal salt and ion supplementation.

[0152] Compared with the comparative example, the present invention, through dual-path determination and the construction of ion compensation dependence coefficient, can avoid misselection based solely on good performance under ion compensation conditions.

[0153] Comparative Example 2: No environmental deviation gating weighting

[0154] This comparative example uses the same dual-path salinity gradient measurement as Example 2, but does not calculate environmental deviation, nor does it downweight or remove abnormal records. If a measurement unit experiences short-term hypoxia or an abnormally high Vibrio count, this environmental anomaly will directly affect the metamorphosis completion rate and recovery survival rate, and will enter the BLUP evaluation process, leading to a deviation in the breeding value estimation.

[0155] In the environmentally gated data of Example 3, the environmental deviation of normal records was 2.64, corresponding to a record weight of 0.728; the environmental deviation of abnormal records, due to significantly reduced dissolved oxygen and significantly increased Vibrio count, was 70.7, corresponding to a record weight of only 0.000208. After applying the gating weighting of this invention, the impact of abnormal records on genetic evaluation was significantly weakened. Comparison of ordination consistency between two independent batches of the same family showed that the Spearman correlation coefficient was 0.699 without weighting, increasing to 0.853 after applying environmental deviation gating weighting. This demonstrates that this invention can improve the cross-batch stability of low-salt breeding phenotypic determination and the reliability of breeding value estimation.

[0156] Example 3: Validation of large-scale low-salt seedling cultivation

[0157] This embodiment is used to verify the seedling cultivation effect of the low-salt breeding new line obtained by the present invention under production conditions. The on-site acceptance test set up 26 cultivation ponds for the low-salt new line group and 4 cultivation ponds for the control group. Both groups used 13.5㎡ cement ponds and were cultivated for 18 to 21 days under the same seedling density, feeding, and management conditions.

[0158] The acceptance statistics are as follows:

[0159]

[0160] The proportion of salinity reduction was calculated by dividing the difference between the average salinity of the control group and the average salinity of the low-salt new strain group by the average salinity of the control group, i.e., it decreased from 12.65‰ to 8.28‰, a reduction of 34.51%; the proportion of increased pond discharge rate was calculated by dividing the difference between the average pond discharge rate of the low-salt new strain group and the average pond discharge rate of the control group by the average pond discharge rate of the control group, i.e., it increased from 69.56% to 78.86%, an increase of 13.38%.

[0161] Figure 10 The churn rate distribution across different rearing ponds is displayed as a scatter plot. Figure 10 As can be seen from the above statistical results, the low-salt new strain group still achieved a higher average hatching rate under conditions where the salinity was significantly lower than that of the control group, indicating that the new strain cultivated by this invention can stably complete seedling cultivation under low-salt conditions.

[0162] Example 4: Performance Comparison of Pond Aquaculture

[0163] This embodiment was used to verify the performance of the low-salinity bred new strain in the subsequent pond culture stage. The low-salinity new strain group used shrimp larvae bred from low-salinity sources, while the control group used shrimp larvae bred from conventional salinity sources. Each group was replicated in 3 ponds, with each pond having an area of ​​5 mu (approximately 0.33 hectares) and a stocking density of 30,000 shrimp / mu (approximately 0.067 hectares). The same feed and management methods were used. After 108 days of culture, 30 shrimp were randomly sampled from each pond to determine their body length and weight.

[0164] The measurement results are as follows:

[0165]

[0166] Calculations showed that the average weight of the low-salt new strain group was 24.27g, while the average weight of the control group was 21.62g, representing an increase of approximately 12.27% in the low-salt new strain group compared to the control group, consistent with the on-site yield measurement result of approximately 12.3%. The average body length of the low-salt new strain group was 10.10cm, while the average body length of the control group was 9.47cm, representing an increase of approximately 6.69%. Figure 11 The average weight difference between the ponds is shown in the form of a bar chart, which shows that the new low-salt breeding strain cultivated in this invention can not only maintain stable hatching in the low-salt seedling stage, but also has good growth performance in the subsequent breeding stage.

[0167] Example 5: Comparison of different selection rules

[0168] This embodiment illustrates the advantages of the comprehensive retention index of the present invention compared to single-index retention. Three retention rules are set: the first is the comprehensive retention rule of the present invention, which simultaneously considers the target salinity effluent rate or survival rate, the uncompensated critical salinity, and the ion compensation dependence coefficient; the second is retention based solely on the ion compensation critical salinity; and the third is retention based solely on the target salinity effluent rate or survival rate.

[0169] Figure 16This shows a comparison of the average ion compensation dependence coefficients of selected families under different selection rules. Figure 16 It is evident that selecting families based solely on critical salinity for ion compensation may result in the selection of families with a high dependence on ion compensation; however, the comprehensive selection rule of this invention can reduce the average ion compensation dependence coefficient of the selected families. Figure 17 This displays a comparison of the culling rate or survival rate of selected families under different selection rules for the target salinity. Figure 17 It is evident that this invention can maintain a high target salinity effluent rate or survival rate while reducing ion compensation dependence.

[0170] Figure 15 The Pareto relationship of multi-objective selection is further demonstrated, indicating that the present invention does not simply pursue extreme optimization of a certain trait, but achieves a comprehensive balance between low uncompensated critical salinity, high target salinity effluent rate and low ion compensation dependence, which is more in line with the industrialization and promotion needs of low-salinity breeding new strains.

[0171] As can be seen from the above embodiments and examples, the present invention has at least the following technical effects.

[0172] First, this invention, through parallel salinity gradient determination using both ion-compensated and non-compensated pathways, can distinguish the low-salt performance of families under ion-compensated conditions from their true low-input performance under non-compensated conditions, and quantifies this difference using an ion-compensation dependence coefficient. This design avoids the problem of misselection in conventional low-salt breeding based solely on performance under compensated conditions.

[0173] Secondly, this invention incorporates temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite, Vibrio count, and abnormal events into phenotypic data quality control through environmental deviation gating weighting. This reduces the interference of water quality fluctuations and pathogen abnormalities on low-salt phenotypes, improves the accuracy of BLUP breeding value estimation, and enhances the comparability of test results from different batches.

[0174] Third, this invention, through weighted BLUP genetic evaluation and comprehensive selection index, simultaneously considers the target salinity discharge rate or survival rate, non-compensated critical salinity, and ion compensation dependence coefficient, and can breed new strains of giant freshwater prawns that can stably complete seedling cultivation under low salinity conditions without being highly dependent on external ion compensation.

[0175] Fourth, through inbreeding constraint mating and multiple generations of iteration, this invention can maintain effective population size and genetic diversity while obtaining genetic progress in low-salt reproductive capacity, making it suitable for long-term breeding and large-scale promotion.

[0176] Fifth, based on the on-site acceptance data of Example 3, the average harvest rate of the low-salt new strain group under an average salinity of 8.28±0.07‰ was 78.86±6.96%, while the average harvest rate of the control group under an average salinity of 12.65±0.06‰ was 69.56±5.02%. The low-salt new strain group had a 34.51% lower salinity and a 13.38% higher harvest rate. Based on the pond culture data of Example 4, the average weight of the low-salt new strain group was 24.27g, while the control group was 21.62g, representing an increase of approximately 12.27%. These results demonstrate that the present invention can balance the stability of low-salt seedling cultivation, subsequent aquaculture performance, and the need for cost reduction and emission reduction.

[0177] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0178] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0179] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0180] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0181] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0182] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0183] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

Claims

1. A method for cultivating a new low-salinity breeding strain of giant freshwater prawn based on BLUP family selection, characterized in that, Includes the following steps: S1. Select healthy parent shrimp from the basic population of giant freshwater prawns, construct full-sib families and / or half-sib families and establish pedigree information; S2. Set up ion compensation path and non-compensation path in parallel for the same family during the metamorphosis critical window to obtain the metamorphosis completion rate and recovery survival rate step by step. S3. Determine the minimum salinity that satisfies the preset metamorphosis completion rate threshold and recovery survival rate threshold under the two paths respectively, obtain the critical salinity for ion compensation and the critical salinity for non-compensation, and construct the ion compensation dependence coefficient. S4. Collect water quality and pathogen environmental indicators, calculate environmental deviation, and weight, deweight, or remove the measurement records accordingly. S5. Based on pedigree information and weighted measurement data, implement the best linear unbiased prediction BLUP genetic assessment and construct a selection index that takes into account the target salinity discharge rate, uncompensated critical salinity and ion compensation dependence coefficient. S6. Based on the selection results, crossbreed and iteratively select and breed under the constraints of the common parentage coefficient or inbreeding coefficient to form a breeding population of giant freshwater prawns that can stably complete seedling cultivation under the target salinity conditions and has low dependence on ion compensation. In step S2, the metamorphosis critical window meets any of the following conditions: the proportion of juvenile shrimp in the nursery unit reaches 50% to 90%; or dense molting occurs in two consecutive daily inspections and the number of juvenile shrimp increases by no less than 30% compared to the previous day; the salinity gradient is measured from an initial salinity of 8‰ to 10‰, decreasing in single-level salinity reduction increments of 0.3‰ to 0.8‰ and maintaining each level for 0.5 hours to 2 hours, gradually decreasing to a final salinity of 4.5‰ to 6.5‰; after maintaining the low salinity critical level for 24 to 72 hours, the salinity is restored to the initial salinity, and observation continues for 12 to 48 hours to obtain the recovery survival rate; In step S3, the threshold for the metamorphosis completion rate is 80% to 90%, and the threshold for the recovery survival rate is 85% to 95%; the ion compensation dependence coefficient is the positive part of the difference between the non-compensated critical salinity and the ion-compensated critical salinity, used to characterize the degree of dependence of the family on ion compensation. In step S4, the environmental indicators include at least temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite and Vibrio count; the environmental deviation is obtained by weighted synthesis of the standardized deviation of each environmental indicator relative to the baseline of the same batch. The greater the environmental deviation, the smaller the weight of the corresponding measurement record. When the Vibrio count, ammonia nitrogen concentration, or nitrite concentration corresponding to the measurement record reaches the corresponding preset threshold, or when a power outage, oxygenation failure, mechanical damage, or abnormal ion dosing event occurs, the measurement record will be downweighted or removed; when the abnormal event affects both the ion compensation path and the non-compensation path, the records corresponding to both paths will be downweighted or removed simultaneously.

2. The method according to claim 1, characterized in that, In step S1, the basic population is a core breeding population of giant freshwater prawns that has been continuously propagated and has breeding records; the healthy broodstock shrimp meet the criteria of no obvious damage to the body surface, intact appendages, normal feeding, normal gonadal development, and negative or below the preset detection threshold for pathogens. And / or, in step S1, nested mating or factor mating is used to construct families; when nested mating is used, each male shrimp is paired with 2 to 3 female shrimp, and the family coefficient is no less than 30 per generation.

3. The method according to claim 1, characterized in that, In step S2, the ion compensation path is a reference path that applies ion compensation while adjusting salinity so that at least one of the key ions among potassium ions, calcium ions, and magnesium ions does not constitute a restriction; the non-compensation path is a measurement path that adjusts salinity only without compensating for the ratio of potassium ions, calcium ions, and magnesium ions. And / or, in step S2, the ion compensation path and the non-compensation path use the same batch of juveniles from the same family, and maintain consistent water temperature, oxygenation, feeding, sewage discharge, water exchange, and daily disinfection management conditions; the two path measurement units are physically isolated from each other to avoid ion addition crosstalk.

4. The method according to claim 1, characterized in that, In step S5, the BLUP genetic assessment uses a mixed linear model, which includes at least batch effect and seedling unit effect as fixed effects, and additive genetic effect and common environmental effect as random effects; wherein, the weights of the measurement records are used for weighted BLUP solution; And / or, in step S5, the selection index increases with the breeding value of the effluent rate or survival rate at the target salinity, and decreases with the breeding value of the non-compensated critical salinity and the breeding value of the ion compensation dependence coefficient; the target salinity is 6‰ to 10‰.

5. The method according to claim 1, characterized in that, In step S6, the mating scheme satisfies the requirement that the inbreeding coefficient is lower than the preset upper limit of inbreeding and the effective population size is not lower than the preset lower limit; repeat steps S1 to S6 for at least 3 generations to obtain the next generation of breeding population and continuously evaluate its low-salt breeding stability.

6. A breeding system for a new low-salinity breeding strain of giant freshwater prawn based on BLUP family selection, characterized in that, The system for implementing the method according to any one of claims 1 to 5, the system comprising: The parent and pedigree management unit is used for parent shrimp registration, health check result entry, mating design generation, pedigree numbering, pedigree information storage and tracing. The seedling and dual-path measurement execution unit is used to set up measurement units with ion compensation paths and non-compensation paths for the same family. The salinity step control unit is used to control the salinity to gradually decrease from the initial salinity to the final salinity in single-stage reduction increments and durations, and to control the stress maintenance and recovery observation process. The ion compensation and dosing unit is used to implement key ion compensation in the ion compensation path and record dosing information; Water quality and pathogen monitoring unit, used to collect water quality and pathogen environmental indicators; The data acquisition and calculation unit is used to collect phenotypic data, environmental data and measurement logs, and to calculate critical salinity, ion compensation dependence coefficient, environmental deviation and measurement record weight. Genetic evaluation and selection decision unit, used to perform weighted BLUP genetic evaluation and calculate the selection index; The mating and inbreeding constraint management unit is used to generate mating schemes and control inbreeding levels and effective population size.

7. The system according to claim 6, characterized in that, The seedling raising and dual-path measurement execution unit includes mutually isolated ion compensation measurement units and non-compensation measurement units. The two types of measurement units are respectively equipped with constant temperature, oxygenation, feeding, sewage discharge and water exchange devices to maintain consistent seedling management conditions except for ion compensation measures. And / or, the salinity step control unit includes a salinity sensor, a freshwater supply device, a brine supply device, a mixing and circulation device, and a controller; the controller is used to perform closed-loop control according to the set initial salinity, final salinity, single-stage salinity reduction range, duration of each stage, duration of stress, and duration of recovery observation; And / or, the water quality and pathogen monitoring unit includes a detection module for detecting temperature, dissolved oxygen, pH, ammonia nitrogen, nitrite and Vibrio count, and sends the detection results to the data acquisition and calculation unit for environmental deviation calculation and measurement record gating; And / or, the data acquisition and calculation unit is configured to associate and store family number, measurement path, salinity level, metamorphosis completion rate, recovery survival rate, pond discharge rate, body length and weight, environmental indicators and abnormal events, and determine the ion-compensated critical salinity and the non-compensated critical salinity based on the same criterion. And / or, the genetic assessment and selection decision unit is configured to generate a kinship matrix based on pedigree information, perform a weighted BLUP solution in combination with the weights of the measurement records, and output the breeding value, selection index and selection list of families and / or individuals; And / or, the mating and inbreeding constraint management unit is configured to generate a mating matrix based on the kinship of selected families and individuals, and output a next-generation mating list when the inbreeding coefficient and effective population size meet preset conditions.

8. An electronic device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the data processing steps of calculating environmental deviation, assigning weights to measurement records, performing BLUP genetic assessment, calculating the selection index, and generating mating schemes in the method of any one of claims 1-5, based on pedigree information, dual-path salinity step measurement data, and environmental index data.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it performs the data processing steps of calculating environmental deviation, allocating measurement record weights, performing BLUP genetic assessment, calculating the selection index, and generating mating schemes in the method of any one of claims 1-5.

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