A pear tree calcium deficiency cause physical and chemical-molecular double index diagnosis method and prescription generation system

Abstract

The present application provides a kind of pear tree calcium deficiency cause physical-chemical-molecular double index diagnosis and prescription generation system and method thereof, belong to fruit tree nutrition diagnosis field.System includes sample collection, physical-chemical detection, calcium ion flow rate detection, molecular detection, discriminant analysis and prescription generation module.Physical-chemical detection obtains leaf calcium content, nitrogen content, fruit calcium content, soil exchangeable calcium and pH value;Non-invasive micro-test technology is used to detect the calcium ion flow rate of different parts of fruit;Molecular detection quantifies the expression amount of calcium signaling pathway marker gene.Discriminant model integrates physical-chemical and molecular indicators, and divides calcium deficiency causes into soil calcium deficiency type, physiological calcium deficiency type and complex calcium deficiency type, and generates individualized calcium supplement prescription containing calcium fertilizer variety, application amount and application method automatically.The present application realizes the accurate classification diagnosis and prescription automatic generation of calcium deficiency cause, and is suitable for precise calcium supplement management of pear tree.

Description

Technical Field

[0001] This invention relates to the technical field, specifically to a physicochemical-molecular dual-indicator diagnostic method and prescription generation system for calcium deficiency in pear trees. Background Technology

[0002] Calcium deficiency in pear trees is a common physiological disorder in production. Symptoms include chlorotic spots on leaves, twisted leaf tips and margins, sunken spots on the fruit surface, and corky browning of the flesh, severely reducing fruit quality and economic benefits. Currently, calcium deficiency diagnosis relies mainly on single indicators such as appearance, leaf calcium content, or soil exchangeable calcium content. This approach is not only inaccurate but also fails to distinguish the root cause of calcium deficiency—whether it's insufficient calcium supply from the soil or a physiological disorder in the plant's absorption, transport, and utilization of calcium. Since it's common for trees to be calcium deficient even when soil calcium levels are normal, relying on single indicators often leads to misdiagnosis. Furthermore, current technologies lack molecular-level diagnostic indicators; changes in the expression of genes related to calcium signaling pathways are not yet included in the diagnostic system, and there is a lack of automatic linkage between diagnostic results and calcium supplementation prescriptions, making it difficult to achieve a closed-loop management system of "accurate etiology identification—automatic prescription generation." Therefore, there is an urgent need to establish a new technology that integrates physicochemical and molecular indicators, can classify and diagnose the causes of calcium deficiency, and automatically generate calcium supplementation plans. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a physicochemical-molecular dual-indicator diagnostic method and prescription generation system for calcium deficiency in pear trees.

[0004] To achieve the aforementioned objective, the technical solution of the present invention is implemented as follows: a physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees, comprising: The sample collection module is used to collect leaf samples, fruit samples, and root soil samples from the pear trees to be tested. The physicochemical testing module is used to perform physicochemical tests on samples to obtain leaf calcium content, leaf nitrogen content, fruit calcium content, soil exchangeable calcium content, and soil pH value. A calcium ion flow rate detection module is used to detect the calcium ion flow rate in different parts of the fruit. The molecular detection module is used to detect the expression levels of calcium signaling pathway-related marker genes in leaf samples; The discriminant analysis module has a built-in model for identifying the cause of calcium deficiency in pear trees. It is used to output the type of cause of calcium deficiency based on a comprehensive analysis of physicochemical and molecular indicators. The prescription generation module is used to generate calcium supplement prescriptions based on the type of calcium deficiency cause. The output module is used to output the type of calcium deficiency and the prescription for calcium supplementation.

[0005] As a further improvement to the system of this invention, the physicochemical detection module includes at least one of inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), or atomic absorption spectrophotometer (AAS). Among these, the ICP-OES method can effectively and simultaneously determine the content of 12 mineral elements, including Ca, P, and K, in pear leaves, providing a reliable method for rapid nutritional diagnosis of pear leaves. The calcium ion flow rate detection module includes a non-invasive micro-test technology (NMT) detection device. Non-invasive micro-test technology can detect the flow rate of ions entering and exiting living organisms without damaging the sample, and features in vivo, dynamic, real-time, long-term, and multi-dimensional scanning and measurement.

[0006] As a further improvement to the system of the present invention, the discriminant model built into the discriminant analysis module is constructed using the method of Scheme 7 of the present invention.

[0007] As a further improvement to the system of this invention, the system also includes an image acquisition module and a symptom recognition module. The image acquisition module is used to acquire images of pear leaves and fruits; the symptom recognition module is used to identify visual symptoms of calcium deficiency based on the images. These visual symptoms include at least one of the following: chlorotic spots on leaves, leaf tip and edge adhesion and distortion, sunken spots on the fruit surface, and corky browning of the fruit pulp. The recognition results from the symptom recognition module are input into the discriminant analysis module as auxiliary diagnostic information.

[0008] This invention also includes: a physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees, comprising the following steps: S1: Collect leaf samples, fruit samples, and root soil samples from the pear trees to be tested; S2: Perform physicochemical tests on leaf samples to obtain leaf calcium and nitrogen content, and calculate leaf nitrogen-calcium ratio; perform physicochemical tests on fruit samples to obtain fruit calcium content, and detect calcium ion flow rate in different parts of the fruit; perform physicochemical tests on soil samples to obtain soil exchangeable calcium content and soil pH value. S3: Total RNA was extracted from leaf samples, and the expression levels of calcium signaling pathway-related marker genes were detected by real-time quantitative PCR (qRT-PCR). S4: Input the data obtained from physicochemical and molecular tests into the pre-constructed calcium deficiency etiology discrimination model for pear trees. The discrimination model outputs the calcium deficiency etiology type based on the comprehensive analysis of physicochemical and molecular indicators. The etiology types include soil calcium deficiency type, physiological calcium deficiency type, and compound calcium deficiency type. S5: Generate a corresponding calcium supplement prescription based on the type of calcium deficiency.

[0009] As a further improvement to the method of this invention, the calcium ion flow rate was detected using non-destructive microelectrometry, measuring the calcium ion flow rate at the calyx and pulp of the fruit. Studies have shown that both bound and free calcium in fruits with hardened apex are significantly lower than in normal fruits, and the calcium absorption rate at the apex is also significantly lower than in normal fruits, indicating that calcium deficiency is a major cause of physiological disorders in fruits. Therefore, the difference in calcium ion flow rate in different parts of the fruit is an important indicator for assessing calcium absorption impairment.

[0010] As a further improvement to the method of the present invention, the calcium signaling pathway-related marker genes include calmodulin (CaM), calcium-dependent protein kinase (CDPK), cyclic nutrient-gated channel (CNGC), and calcium pump (Ca) genes. 2+ At least two of the following are present: calmodulin (CDL) and calcium-dependent protein kinase (C-ATPase). Calmodulin is a major participant in plant calcium signaling pathways; calcium-dependent protein kinases are important calcium signaling receptors in higher plant cells; and the expression of cyclic nucleotide-gated ion channel genes changes significantly under low calcium stress. The expression levels of these genes can sensitively reflect the molecular response of plants to calcium deficiency stress.

[0011] Methods for constructing discriminative models include: Case samples and healthy samples of pear trees with calcium deficiency were collected. Data on leaf calcium content, leaf nitrogen-calcium ratio, fruit calcium content, fruit calcium ion flow rate, soil exchangeable calcium content, soil pH value, and expression levels of calcium signaling pathway marker genes were obtained for each sample. After standardization, a discriminant model was trained using machine learning algorithms. The machine learning algorithms were selected from support vector machine (SVM), random forest, gradient boosting decision tree (GBDT), or neural network.

[0012] The logic for differentiating the causes of calcium deficiency is as follows: When both the soil exchangeable calcium content and the leaf calcium content are below their respective thresholds, the soil is identified as calcium-deficient. When the soil exchangeable calcium content is normal but the leaf calcium content is below the threshold, and / or the fruit calcium ion flow rate is abnormal, and / or the expression level of calcium signaling pathway marker genes is abnormal, it is determined to be physiological calcium deficiency type. When both soil exchangeable calcium content and leaf calcium content are below the threshold, and there are also abnormal calcium ion flow rates or abnormal marker gene expression levels in the fruit, it is identified as a complex calcium deficiency type.

[0013] The critical value for soil exchangeable calcium deficiency is 400 mg / kg soil. When the soil pH is high (e.g., pH > 8.5), sodium ions are abundant, leading to poor calcium ion exchange and insufficient calcium absorption by crops. The optimal values ​​for leaf and fruit calcium content are determined based on the pear leaf nutrient diagnostic standards.

[0014] Option 5: The generation of a calcium supplement prescription includes: Based on the type of calcium deficiency, a basic prescription is retrieved from the prescription knowledge base. The calcium requirement is calculated based on the deviation of leaf calcium content, fruit calcium content from the standard value, and soil improvement plan and calcium fertilizer type are determined based on soil exchangeable calcium content and pH value. A comprehensive calcium supplementation prescription is generated, which includes calcium fertilizer type, application amount, application time, application method and application frequency.

[0015] The selection rules for calcium fertilizer varieties are as follows: For soils deficient in calcium, apply calcium fertilizers (such as quicklime, gypsum, calcium nitrate, etc.) to the soil. For physiological calcium deficiency, foliar spraying of calcium fertilizer (such as calcium nitrate, amino acid calcium, sugar alcohol calcium, etc.) can be used. For compound calcium deficiency, both soil application of calcium fertilizer and foliar spraying of calcium fertilizer should be used.

[0016] The beneficial effects of this invention are reflected in: This invention, for the first time, combines physicochemical indicators (leaf calcium content, nitrogen-to-calcium ratio, fruit calcium content, soil exchangeable calcium, pH value, and calcium ion flow rate in different parts of the fruit) with molecular indicators (expression levels of calcium signaling pathway marker genes) to construct a comprehensive dual-indicator diagnostic system, significantly improving the accuracy of calcium deficiency diagnosis. Through a discriminant model, the causes are subdivided into soil-induced calcium deficiency, physiological calcium deficiency, and combined calcium deficiency, breaking through the limitations of traditional "whether calcium is deficient" methods and achieving precise classification of causes, providing a scientific basis for targeted calcium supplementation. Non-destructive micro-measurement technology is introduced to detect the calcium ion flow rate in living fruit, directly reflecting the calcium absorption status; the introduction of molecular indicators enables early diagnosis. The system automatically generates personalized prescriptions based on the cause type, including calcium fertilizer variety, application rate, timing, and method, forming a "diagnosis-prescription" closed loop. Image recognition can be optionally added to assist in symptom identification, improving convenience. This invention can effectively guide precise calcium supplementation, reduce physiological diseases in fruits, improve quality and efficiency, and is suitable for large-scale orchards and agricultural technology extension. Attached Figure Description

[0017] In the attached diagram: Figure 1 This is a block diagram of the overall structure of the physicochemical-molecular dual-indicator diagnosis and prescription generation system for calcium deficiency in pear trees according to the present invention.

[0018] Figure 2 This is a flowchart illustrating the diagnostic method for calcium deficiency in pear trees according to the present invention.

[0019] Figure 3 This is a logic diagram for identifying the cause of calcium deficiency in this invention.

[0020] Figure 4 This is a schematic diagram of the process for generating the calcium supplement prescription of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, and not all of them. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that if the embodiments of the invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, "multiple" refers to two or more. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the invention.

[0024] Example 1 System Configuration This embodiment provides a physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees, which includes the following modules.

[0025] (a) Sample Acquisition Module Leaf, fruit, and root soil samples were collected from the pear trees to be tested. Leaf sample collection: During the growing season, collect 2-3 physiologically mature leaves from the middle of each of the four outer directions (east, south, west, and north) of the current year's growth branches, 20-30 leaves per tree. Mix the leaves and store them temporarily in an ice box. Fruit sample collection: During the ripening period or disease outbreak period, collect 2-3 fruits from each of the four outer directions of the tree canopy, 8-12 fruits per tree. Soil sample collection: Near the drip line of the canopy, avoiding fertilizer trenches, collect two layers (0-20 cm and 20-40 cm) using a five-point or S-shaped sampling method, approximately 500 g per layer. Air dry, grind, and sieve for later use.

[0026] (II) Physicochemical Testing Module This method is used to obtain leaf calcium content, leaf nitrogen content, fruit calcium content, soil exchangeable calcium content, and soil pH. Leaf samples: rinsed with tap water-distilled water-deionized water, blanched at 105℃ for 30 min, dried at 65-70℃ to constant weight, pulverized and sieved (40 or 60 mesh), and 0.2000-0.5000 g was weighed, digested, and diluted to volume. Fruit samples: peeled and pitted, pulp collected, freeze-dried, pulverized, and digested. Soil samples: air-dried, passed through a 2 mm sieve, pH measured (potential method, water-to-soil ratio 2.5:1), passed through a 0.25 mm sieve, and extracted using ammonium acetate exchange method to measure exchangeable calcium. At least one of ICP-OES, ICP-MS, or AAS is used for determination, with ICP-OES preferred for simultaneous determination of Ca, P, K, Mg, Fe, Mn, Cu, Zn, and B.

[0027] (III) Calcium ion flow rate detection module Non-destructive micrometry (NMT) equipment was used to detect calcium content in the calyx and pulp of the fruit. 2+ Flow rate. Procedure: Rinse fresh, whole fruit with deionized water, aspirate dry, fix in a measuring dish, and add test buffer (0.1 mM KCl, 0.1 mM CaCl2, 0.3 mM MES), Ca... 2+ Selective microelectrodes (tip 2-5 μm) are placed 30-50 μm from the surface. A three-dimensional control system drives the electrodes to reciprocate vertically (approximately 30 μm), recording the voltage difference. This difference is then converted to Ca based on the Nernst equation and Fick's first law. 2+ Net flow rate (pmol·cm) -2 ·s -1 Each point was measured continuously for 5-10 minutes.

[0028] (iv) Molecular detection module This is used to detect marker genes related to the calcium signaling pathway in leaves (calmodulin gene CaM, calcium-dependent protein kinase gene CDPK, calcium ion channel protein gene CNGC, calcium pump gene Ca). 2+ Expression levels of at least two of the +-ATPases. Procedure: Take approximately 100 mg of fresh leaf extract and grind it in liquid nitrogen. Extract total RNA using TRIzol or a kit. Integrity is assessed by agarose gel electrophoresis, and concentration and purity are determined by UV spectrophotometry. 260 / A 2801.8–2.1). 1–2 μg of total RNA was reverse transcribed to synthesize cDNA. Specific qRT-PCR primers were designed, using Actin or 18S rRNA as internal controls. A 20 μL SYBR Green assay system (2 μL cDNA, 0.5 μL each of forward and reverse primers (10 μM), 10 μL SYBR Green Master Mix, 7 μL ddH2O) was used. The reaction program was: 95℃ pre-denaturation for 3 min; 95℃ denaturation for 15 s, 55–60℃ annealing for 30 s, 72℃ extension for 30 s, 40 cycles; melting curve at 65–95℃. Relative expression levels were calculated using the 2^(-ΔΔCt) method.

[0029] (v) Discriminant Analysis Module The system incorporates a model for identifying calcium deficiency in pear trees, analyzing physicochemical and molecular indicators to determine the type of calcium deficiency. Model construction method: Over 200 cases of calcium deficiency and healthy samples were collected, and physicochemical indicators (leaf calcium content, leaf nitrogen-to-calcium ratio, fruit calcium content, and calyx / flesh calcium content) were obtained for each sample. 2+ Flow rate, soil exchangeable calcium, pH, and molecular indicators (relative expression levels of the aforementioned genes) were normalized using Z-scores and trained using machine learning algorithms. Algorithms were selected from SVM, random forest, gradient boosting decision tree, or neural networks, with random forest being the preferred choice (500 trees, maximum depth 10, optimized using 5-fold cross-validation). Classification accuracy, sensitivity, and specificity were validated using an independent test set. The discrimination logic was as follows: soil exchangeable calcium < 400 mg / kg and leaf calcium below the threshold were classified as calcium-deficient soil; soil exchangeable calcium was normal, but leaf calcium was below the threshold, and / or fruit calcium... 2+ Abnormal flow velocity and / or abnormal marker gene expression (relative fold significantly deviating from 1.0) are classified as physiological calcium deficiency type; both soil exchangeable calcium and leaf calcium are below the threshold and there are also abnormal flow velocity or expression levels, which are classified as compound calcium deficiency type.

[0030] (vi) Prescription generation module Calcium supplementation prescriptions were generated based on the etiology of calcium deficiency. Methods: Basic prescriptions were retrieved from a prescription knowledge base; calcium requirements were calculated based on the deviations of leaf and fruit calcium from standard values; soil improvement plans were determined based on soil exchangeable calcium and pH (quicklime for acidic soils, gypsum, sulfur, etc. for alkaline soils); calcium fertilizer selection—soil-applied calcium fertilizers (quicklime, gypsum, calcium nitrate) were used for soil-deficient calcium types, foliar-applied calcium fertilizers (calcium nitrate, amino acid calcium, sugar alcohol calcium, EDTA-Ca) were used for physiological calcium deficiency types, and both methods were used for compound calcium deficiency types; a complete prescription was generated, including the type, dosage, application time, method, and frequency of calcium fertilizer application.

[0031] (vii) Output module It is used to output the type of calcium deficiency and calcium supplementation prescription, in formats including display screen, printing, mobile terminal push, cloud storage, etc.

[0032] Optionally, the system may also include an image acquisition module and a symptom recognition module. The image acquisition module acquires images of leaves and fruits; the symptom recognition module automatically identifies visual symptoms of calcium deficiency (chlorotic spots on leaves, leaf tip and edge adhesion and distortion, sunken spots on the fruit surface, and corky browning of the fruit pulp) based on a deep learning model. The recognition results are used as auxiliary diagnostic information input into the discriminant analysis module to improve the comprehensiveness of the diagnosis.

[0033] Example 2 Diagnostic Method This embodiment provides a physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees, including the following steps: S1. Sample collection: During the fruit enlargement to maturity period of pear trees, select plants with typical calcium deficiency symptoms in the target pear orchard and collect leaf, fruit and root soil samples according to the method in Example 1.

[0034] S2. Physicochemical Detection: Leaf calcium content, leaf nitrogen content (calculation of nitrogen-calcium ratio), fruit calcium content, soil exchangeable calcium content, and soil pH were obtained according to the physicochemical detection module method in Example 1; NMT was used to detect the calcium content in the calyx and pulp of the fruit according to the calcium ion flow rate detection module method. 2+ Flow rate.

[0035] S3. Molecular detection: Total RNA was extracted from leaves according to the molecular detection module method in Example 1, and the expression levels of calcium signaling pathway-related marker genes (at least two) were detected by qRT-PCR.

[0036] S4. Discriminant analysis: Input the above data into the pre-constructed pear tree calcium deficiency etiology discrimination model. The model outputs the calcium deficiency etiology type (soil calcium deficiency type, physiological calcium deficiency type, or compound calcium deficiency type). The discrimination logic is the same as in Example 1.

[0037] S5. Prescription Generation: Generate a calcium supplementation prescription based on the cause of the deficiency. Soil-induced calcium deficiency: Primarily apply calcium fertilizer to the soil. It is recommended to apply quicklime or calcium nitrate after fruit harvest in autumn or before bud break in spring. The dosage is calculated based on the difference between the measured and target values, combined with increased application of organic fertilizer. Physiological calcium deficiency: Primarily apply calcium fertilizer via foliar spraying. After flowering, during fruit enlargement, and before harvest, spray 0.3%~0.5% calcium nitrate, amino acid calcium, or sugar alcohol calcium in several applications, with an interval of 7~10 days, for 2~3 consecutive times. Simultaneously investigate and correct factors such as excessive nitrogen fertilizer, drought, waterlogging, and root diseases. Compound calcium deficiency: Combine soil application of calcium fertilizer with foliar spraying of calcium fertilizer, with the same treatment plan as the two types mentioned above.

[0038] Example 3: Model Optimization and Validation This embodiment provides a method for optimizing and validating the discriminant model.

[0039] Feature selection: Recursive Feature Elimination (RFE) was used to select the subset of features that contributed the most from all candidate indicators. The optimal combination was leaf calcium content, leaf nitrogen-calcium ratio, fruit calcium content, and Ca content in the calyx of the fruit. 2+ Flow velocity, soil exchangeable calcium content, and relative expression level of calmodulin gene.

[0040] Model Comparison and Optimization: The performance of SVM, Random Forest, GBDT, and Neural Networks on the same training / test set is compared. Evaluation metrics include overall accuracy, macro-average F1 score, and various precision and recall rates. Hyperparameters are optimized using grid search and cross-validation. Taking Random Forest as an example, the number of decision trees, maximum depth, and minimum number of sample splits are optimized.

[0041] Model validation: The generalization ability of the final model is validated using an independent validation set that was not involved in training and tuning.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees, characterized in that, include: The sample collection module is used to collect leaf samples, fruit samples, and root soil samples from the pear trees to be tested. The physicochemical detection module is used to perform physicochemical detection on the sample to obtain leaf calcium content, leaf nitrogen content, fruit calcium content, soil exchangeable calcium content, and soil pH value. A calcium ion flow rate detection module is used to detect the calcium ion flow rate in different parts of the fruit. The molecular detection module is used to detect the expression levels of calcium signaling pathway-related marker genes in leaf samples; The discriminant analysis module has a built-in model for identifying the cause of calcium deficiency in pear trees. It is used to output the type of cause of calcium deficiency based on a comprehensive analysis of physicochemical and molecular indicators. A prescription generation module is used to generate a calcium supplementation prescription based on the type of calcium deficiency etiology. The output module is used to output the type of calcium deficiency and the calcium supplementation prescription.

2. The physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees according to claim 1, characterized in that, The physicochemical detection module includes at least one of an inductively coupled plasma atomic emission spectrometer, an inductively coupled plasma mass spectrometer, or an atomic absorption spectrophotometer; the calcium ion flow rate detection module includes a non-destructive micro-measurement technology detection device.

3. The physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees according to claim 1, characterized in that, The discriminant model built into the discriminant analysis module is constructed using the method described in claim 7.

4. The physicochemical-molecular dual-indicator diagnostic and prescription generation system for calcium deficiency in pear trees according to claim 1, characterized in that, It also includes an image acquisition module and a symptom recognition module. The image acquisition module is used to acquire images of pear leaves and fruits. The symptom recognition module is used to identify visual symptoms of calcium deficiency based on the images. The visual symptoms include at least one of the following: chlorotic spots on leaves, leaf tip and leaf margin adhesion and twisting, sunken spots on the fruit surface, and corky browning of the fruit pulp. The recognition results of the symptom recognition module are input into the discriminant analysis module as auxiliary diagnostic information.

5. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 1, characterized in that, Includes the following steps: Leaf samples, fruit samples, and root soil samples were collected from the pear trees to be tested. The leaf samples were subjected to physicochemical tests to obtain the calcium and nitrogen content of the leaves and to calculate the nitrogen-calcium ratio of the leaves; the fruit samples were subjected to physicochemical tests to obtain the calcium content of the fruit and to detect the calcium ion flow rate in different parts of the fruit; the soil samples were subjected to physicochemical tests to obtain the exchangeable calcium content and pH value of the soil. Total RNA was extracted from the leaf samples, and the expression levels of calcium signaling pathway-related marker genes were detected by real-time quantitative PCR. The data obtained from the physicochemical and molecular tests are input into a pre-constructed calcium deficiency etiology discrimination model for pear trees. The discrimination model outputs the calcium deficiency etiology type based on the comprehensive analysis of physicochemical and molecular indicators. The etiology types include soil calcium deficiency type, physiological calcium deficiency type, and compound calcium deficiency type. Based on the type of calcium deficiency, a corresponding calcium supplement prescription is generated.

6. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 5, characterized in that, The calcium ion flow rate was detected using non-destructive microelectrometry, measuring the calcium ion flow rate in the calyx and pulp of the fruit, respectively. The calcium signaling pathway-related marker genes include at least two of the following: calmodulin gene, calcium-dependent protein kinase gene, calcium ion channel protein gene, and calcium pump gene.

7. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 5, characterized in that, The method for constructing the discriminant model includes: collecting calcium deficiency case samples and healthy samples of pear trees, obtaining data on leaf calcium content, leaf nitrogen-calcium ratio, fruit calcium content, fruit calcium ion flow rate, soil exchangeable calcium content, soil pH value, and expression level of calcium signaling pathway marker genes for each sample, performing standardization processing, and then training the discriminant model using a machine learning algorithm, wherein the machine learning algorithm is selected from support vector machine, random forest, gradient boosting decision tree, or neural network.

8. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 5, characterized in that, The discrimination logic for the cause of calcium deficiency is as follows: when both the exchangeable calcium content in the soil and the calcium content in the leaves are below their respective thresholds, it is determined to be soil-type calcium deficiency; when the exchangeable calcium content in the soil is normal but the calcium content in the leaves is below the threshold, and / or the calcium ion flow rate in the fruit is abnormal, and / or the expression level of calcium signaling pathway marker genes is abnormal, it is determined to be physiological calcium deficiency; when both the exchangeable calcium content in the soil and the calcium content in the leaves are below the thresholds and there is also abnormal calcium ion flow rate in the fruit or abnormal expression level of marker genes, it is determined to be compound calcium deficiency.

9. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 5, characterized in that, The generation of the calcium supplement prescription includes: retrieving a basic plan from the prescription knowledge base based on the type of calcium deficiency; calculating the calcium supplementation requirement based on the deviation of leaf calcium content, fruit calcium content from the standard value; determining the soil improvement plan and calcium fertilizer variety based on the soil exchangeable calcium content and pH value; and comprehensively generating a calcium supplement prescription that includes calcium fertilizer variety, application amount, application time, application method and application frequency.

10. The physicochemical-molecular dual-indicator diagnostic method for calcium deficiency in pear trees according to claim 9, characterized in that, The selection rules for calcium fertilizer varieties are as follows: for soil-deficient calcium type, soil-applied calcium fertilizer is selected; for physiological calcium deficiency type, foliar-sprayed calcium fertilizer is selected; for compound calcium deficiency type, both soil-applied calcium fertilizer and foliar-sprayed calcium fertilizer are selected.

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