A method for breeding superior diploid and tetraploid varieties of Fujian oyster with black shell based on Lab chromatographic quantification and comprehensive breeding value analysis, and for the cultivation of triploid varieties.

Abstract

This invention discloses a method for selecting and breeding superior black-shelled diploid and tetraploid Fujian oysters and cultivating triploids based on Lab colorimetric quantification and comprehensive breeding value analysis. The method first utilizes the CIELAB colorimetric evaluation system to establish a shell color quantification standard with lightness value (L*) as the core, and digitally screens black-shelled diploid and tetraploid Fujian oyster parents. Second, based on the L* value and production traits of the offspring, the comprehensive breeding value of the parents is evaluated. Then, based on the comprehensive breeding value, a core breeding population of black-shelled Fujian oyster diploids and tetraploids is constructed. Finally, the core breeding population is optimized, and a black-shelled triploid Fujian oyster population is constructed through diploid and tetraploid hybridization. This invention transforms subjective shell color judgment into objective physical indicators, combined with genetic evaluation, effectively solving problems such as ambiguous parent selection standards and low purity of black shell color traits in offspring production of black-shelled triploid Fujian oysters, achieving precise breeding of high-quality black-shelled Fujian oysters.

Description

Technical Field

[0001] This invention belongs to the field of shellfish breeding technology, specifically involving a method for selecting and breeding superior varieties of diploid and tetraploid oysters with black shells in Fujian based on Lab colorimetric quantification and comprehensive breeding value analysis, as well as a method for cultivating triploid oysters. Background Technology

[0002] The main farmed oysters in my country are giant oysters, including the Pacific oyster, the Fujian oyster, and the Hong Kong oyster. Among them, the Fujian oyster is the highest-producing farmed oyster species in my country, with a production of 2.3565 million tons in 2024, accounting for 32.49% of the total farmed oyster production in China.

[0003] The application of triploid oysters has significantly increased the yield of oysters in Fujian. However, triploid oysters are difficult to produce viable offspring. Therefore, genetic improvement of triploid oysters often involves first improving their diploid and tetraploid parents, and then transferring the superior traits of the parents to the triploid offspring through interploid hybridization, thus achieving genetic improvement of triploid oysters. Therefore, genetic improvement of diploid and tetraploid oyster parents is particularly important.

[0004] In recent years, with the development of genetic improvement efforts for Fujian oysters, their growth traits have been significantly improved. However, the selection of superior shell-colored strains for Fujian oysters remains limited, with the consumer market showing particular preference for black-shelled Fujian oysters. Currently, the breeding of black-shelled Fujian oyster strains mainly relies on the experience of breeders, judging the degree of blackness by visual inspection. However, visual observation is significantly affected by light, has large subjective errors, limited resolution, and lacks data-supported standards.

[0005] CIELAB is an internationally recognized color space. L (Lightness)* represents brightness, with 0 being pure black and 100 being pure white. * Value (chromaticity index of red and green axis) and b * Value (yellow-blue axis chromaticity index). By using a computer vision system and a uniform color space L*a*b* to collect and quantify Fujian oyster shell color data, the differences in visual observation of the black trait of Fujian oyster shells can be avoided, and the data can be recorded, traced, and statistically analyzed, providing the possibility for precision breeding of Fujian oyster shell color traits. Summary of the Invention

[0006] This invention addresses the challenges of significant differences in the visual observation of black shell traits and the lack of quantitative standards during the genetic improvement of black-shelled oyster strains in Fujian. It develops a method for selecting superior diploid and tetraploid varieties of black-shelled Fujian oysters and cultivating triploid strains based on Lab chromaticity quantification and comprehensive breeding value analysis. The diploid and tetraploid black-shelled Fujian oyster strains cultivated using this method exhibit rapid growth and pure shell color, providing a theoretical and practical foundation for the breeding of superior diploid and tetraploid black-shelled Fujian oyster strains and the industrial application of triploid black-shelled Fujian oyster strains.

[0007] A method for breeding superior diploid and tetraploid varieties of Fujian oyster with black shells and for cultivating triploid varieties based on Lab colorimetric quantification and comprehensive breeding value analysis, characterized by the following steps:

[0008] a. Selection of parent shells: Measure growth traits such as shell height and wet weight of all individuals, as well as shell color traits of the left valve.

[0009] b. Constructing full-sib families: Select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value from step a as parents, and construct diploid and tetraploid full-sib families respectively.

[0010] c. Targeted breeding: From diploid full-sib families, 90 oysters are randomly selected from each family. Their shell height, wet weight, and L* value are measured, and the overall breeding value of each family is evaluated. The top 10% of families with the best overall breeding value are selected, and the top 10% of individuals with the largest shell height and wet weight and the smallest L* value from the retained families are used as parents. Targeted breeding of these families is carried out for 2-3 generations.

[0011] d. Constructing a core breeding population: Using diploid full-sib families selected through 2-3 generations of targeted breeding in step c as parents, select the top 10% of families based on comprehensive breeding value as the evaluation index. From the retained families, select 100 males and 100 females from the top 10% of individuals with the largest shell height and wet weight and the smallest L* value. The core breeding population of diploid Fujian oyster with black shell can be obtained by using a group selection method. The core breeding population of tetraploid Fujian oyster with black shell is cultivated in the same way.

[0012] e. From the diploid core breeding group, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value as the female parent, and from the tetraploid core breeding group, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value as the male parent. Through interploid hybridization, the triploid Fujian oyster black-shelled strain can be obtained.

[0013] Further, in step (a), the left shell of each oyster was photographed using a digital camera (Nikon D80), with the camera positioned vertically 30 cm above the sample. Two 20-watt fluorescent lamps (color temperature 6500K) were placed 30 cm above the sample, with the camera lens axis at approximately a 45-degree angle to the light source axis. Under standard shooting conditions, the camera was set to manual mode with the following parameters: ISO 200, aperture f / 5.6, exposure time 1 / 160 second, auto zoom, flash off, and JPEG format. To minimize the influence of external light and reflections, the entire lighting and camera setup were placed in a dark room. The L, a, and b values ​​of each oyster were analyzed using Photoshop (Adobe Photoshop 2024). To ensure the purity of the shell color and avoid deviations to dark purple or dark brown, individuals with hues significantly deviating from the central axis were removed during the selection process by monitoring changes in a* (red-green hue) and b* (yellow-blue hue).

[0014] Furthermore, in steps (b) and (c), the family pedigree is constructed as a one-to-one whole sibling pedigree, and the number of families constructed is 30-50.

[0015] Furthermore, in step (d), when conducting population selection, the selection intensity is 1.6 to 1.9.

[0016] Beneficial effects of the present invention

[0017] The technical solution provided by this invention has the following advantages compared with known technologies.

[0018] This invention first collects and quantifies shell color data using a computer vision system and a uniform color space L*a*b*, avoiding significant differences observed by the naked eye. Through family selection, using shell height, wet weight, and brightness L* as comprehensive indicators, the top 10% of families with the best overall breeding values ​​are retained, and diploid and tetraploid core breeding populations are constructed through group selection. Triploid populations are then constructed from the selected core breeding populations. Compared to the control group, the new diploid, triploid, and tetraploid black-shelled strains bred in this invention show a 10%–15% increase in growth rate and a 5%–12% decrease in brightness. While possessing excellent growth traits, the black color trait is significantly improved, demonstrating broad prospects for industrial application. Attached Figure Description

[0019] Figure 1 This is a technical roadmap for the breeding of diploid and tetraploid varieties of Fujian oyster with black shells, based on Lab colorimetric quantification and comprehensive breeding value analysis. Detailed Implementation

[0020] The present invention will be further illustrated by specific embodiments below, but these are not intended to limit the invention.

[0021] Example

[0022] a. Selection of parent oysters: In March 2024, 5000 black-shelled diploid and tetraploid Fujian oysters were randomly collected from Rongcheng, Shandong Province. The shell height and wet weight of all individuals were measured. The left shell of each oyster was photographed using a digital camera (Nikon D80), positioned vertically 30 cm above the sample. Two 20-watt fluorescent lamps (color temperature 6500K) were placed 30 cm above the sample, with the camera lens axis at approximately a 45-degree angle to the light source axis. Under standard shooting conditions, the camera was set to manual mode with the following parameters: ISO 200, aperture f / 5.6, exposure time 1 / 160 second, auto zoom, flash off, and JPEG format. To minimize the influence of external light and reflections, the entire lighting and camera setup were placed in a dark room. The L, a, and b values ​​of each oyster were analyzed using Photoshop (Adobe Photoshop 2024).

[0023] b. Constructing full-sib families: Select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value from step a as parents, and construct diploid and tetraploid full-sib families respectively.

[0024] c. Targeted breeding: From diploid full-sib families, 90 oysters are randomly selected from each family. Their shell height, wet weight, and L* value are measured, and the overall breeding value of each family is evaluated. The top 10% of families with the best overall breeding value are selected, and the top 10% of individuals with the largest shell height and wet weight and the smallest L* value from the retained families are used as parents. Targeted breeding of these families is carried out for 2-3 generations.

[0025] d. Constructing a core breeding population: Using the diploid full-sib families selected through 2-3 generations of targeted breeding in step c as parents, select the top 10% of families based on comprehensive breeding value as the evaluation index. From the retained families, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value, and select 100 males and 100 females. The core breeding population of the diploid Fujian oyster black-shelled strain can be obtained by using a group selection method. The core breeding population of the tetraploid Fujian oyster black-shelled strain is cultivated in the same way.

[0026] e. From the diploid core breeding population, the top 10% of individuals with the largest shell height and wet weight and the smallest L* value were selected as the female parent. From the tetraploid core breeding population, the top 10% of individuals with the largest shell height and wet weight and the smallest L* value were selected as the male parent. Triploid Fujian oyster black-shelled strains were obtained through interploid hybridization. The obtained diploid, triploid, and tetraploid Fujian oyster strains, as well as the control group, were transferred to the main aquaculture sites in Rongcheng, Shandong for trial cultivation. The production data of each group were recorded in Table 1.

[0027] As shown in Table 1, this embodiment demonstrates that the breeding method based on Lab colorimetric quantification and comprehensive breeding value analysis described in this invention, used for the breeding of diploid and tetraploid core breeding populations of black-shelled Fujian oysters, as well as the triploid new lines obtained from interploid hybridization of the two, exhibits a 14.19%–34.61% increase in shell height and a 20.36%–58.23% increase in wet weight compared to the control group. The shell color brightness value (L*) is also reduced by 25.52%–41.91% compared to the control group. Simultaneously, the shell color variation coefficient decreases by 22.13%–45.08%, and the population uniformity is significantly improved. This invention significantly improves growth traits while also significantly enhancing the purity and stability of the black shell trait. It provides a solid theoretical and practical foundation for the breeding of superior diploid and tetraploid varieties of black-shelled Fujian oysters and the industrial production of triploid black-shelled Fujian oysters, and has broad prospects for industrial application.

[0028] Table 1. Comparison of production performance of diploid, tetraploid, and triploid new strains of black-shelled Fujian oyster and the control group.

[0029]

[0030] The above description is only used to illustrate the technical solutions and features of the present invention, and is not intended to limit the scope of protection of the present invention. Any simple modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A method for selecting and breeding superior diploid and tetraploid varieties of Fujian oyster with black shells and cultivating triploid varieties based on Lab colorimetric quantification and comprehensive breeding value analysis, characterized in that, Includes the following steps: a. Quantification of black color in parents: Growth traits such as shell height and wet weight were measured for all individuals. Shell color data were collected and quantified using a computer vision system and a uniform color space L*a*b*. b. Constructing full-sib families: Select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value from step a as parents, and construct diploid and tetraploid full-sib families respectively. c. Targeted breeding: From diploid full-sib families, 90 oysters are randomly selected from each family. Their shell height, wet weight, and L* value are measured, and the overall breeding value of each family is evaluated. The top 10% of families with the best overall breeding value are selected, and from the retained families, the top 10% of individuals with the largest shell height and wet weight and the smallest L* value are selected as parents. Targeted family breeding is carried out for 2-3 generations. d. Constructing a core breeding population: Using the diploid full-sib families selected through 2-3 generations of targeted breeding in step c as parents, select the top 10% of families based on comprehensive breeding value as the evaluation index. From the retained families, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value, and select 100 males and 100 females. The core breeding population of the diploid Fujian oyster black-shelled strain can be obtained by using a population selection method. The core breeding population of the tetraploid Fujian oyster black-shelled strain can be obtained in the same way. e. Triploid new strain: From the diploid core breeding group, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value as the female parent, and from the tetraploid core breeding group, select the top 10% of individuals with the largest shell height and wet weight and the smallest L* value as the male parent. Through interploid hybridization, the triploid Fujian oyster black-shell strain can be obtained.

2. The method according to claim 1, characterized in that: In step (a), the specific operation of colorimetric measurement is as follows: A digital camera is used to photograph the left shell of each oyster, with the camera positioned vertically 30 cm above the sample. Two 20-watt fluorescent lamps (color temperature 6500K) are placed 30 cm above the sample, with the camera lens axis at approximately a 45-degree angle to the light source axis. Under standard shooting conditions, the camera is set to manual mode with the following parameters: ISO 200, aperture f / 5.6, exposure time 1 / 160 second, auto zoom, flash off, and JPEG format. To minimize the influence of external light and reflections, the entire lighting and camera setup is placed in a dark room. The L, a, and b values ​​of each oyster are analyzed using Photoshop. A standard gray card is used alongside the oyster during shooting for white balance correction. L * Calculated using the following formula: The L * The smaller the value, the darker the shell color. In the breeding process, this invention evaluates the changes in a* (red-green hue) and b* (yellow-blue hue) to eliminate individuals whose hue significantly deviates from the central axis.

3. The method according to claim 1, characterized in that: In step (c), the breeding values ​​and variance components of growth and shell color traits for each family were estimated using ASReml R 4.

0. The comprehensive breeding value index I, on which parental selection was based, was calculated using the following formula: In the formula, , These are the standardized estimated breeding values ​​for shell height, wet weight, and L* trait for each family; , , These are the weighting coefficients. , , ∈ [0, 1] and = 1. Select the families or individuals with the best overall breeding value from the parental selection.

4. The method according to claim 1, characterized in that: In steps (b) and (c), the family pedigree is constructed as a one-to-one whole sibling pedigree, and the number of families constructed is 30-50.

5. The method according to claim 1, characterized in that: In step (d), when conducting population selection, the selection intensity is 1.6 to 1.9.

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