High-temperature-resistant machine-picked cotton molecular breeding method
By combining targeted high-temperature window treatment during flowering, screening using machine harvesting vibration simulation, and simultaneous screening during defoliation and boll opening, the problem of the inability to directionally control the effects of high temperatures in existing technologies has been solved, enabling stable identification of high-temperature resistant cotton materials and screening for their adaptability to mechanical harvesting.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF ECONOMIC CROP HUBEI ACADEMY OF AGRI SCI
- Filing Date
- 2026-03-06
- Publication Date
- 2026-07-14
AI Technical Summary
In existing heat-resistant cotton breeding methods, the effects of high temperatures cannot be controlled in a targeted manner during the formation of flower organs and the pollination and fertilization stages, making it difficult to stably identify the heat-resistant responses of different materials during the reproductive stage.
A combined approach was adopted, consisting of high-temperature window treatment during flowering, vibration simulation screening treatment during machine harvesting, and simultaneous screening treatment during defoliation and boll opening. By using local heating, mechanical vibration, and liquid spraying treatment, a comprehensive selection index for high-temperature resistant machine harvesting was constructed to screen out cotton materials that are resistant to high temperatures and suitable for mechanical harvesting.
This method enables the formation of distinguishable boll formation differences within separate populations, improves the stability of the boll-forming process and the stability of mechanical vibration response under high-temperature conditions, and ensures the adaptability of cotton materials to high-temperature environments and mechanical harvesting.
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Figure CN121795314B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of crop molecular breeding technology, and in particular to a molecular breeding method for high-temperature resistant machine-harvested cotton. Background Technology
[0002] As an important economic crop, cotton's yield formation process is closely related to the environmental conditions during its reproductive growth stage. In cotton-producing areas, high temperatures typically occur during the flowering and boll-setting period, when the plant transitions from vegetative growth to reproductive growth. Pollen formation, pollination and fertilization, and boll development are all highly sensitive to temperature changes.
[0003] Current heat-resistant cotton breeding methods typically employ natural high-temperature environments for population selection. This involves field observations of planted populations during the hot season, with selection based on boll count or boll formation rate. In this approach, high-temperature stress originates from the natural environment, and its timing, duration, and intensity vary with climatic conditions. Furthermore, high temperatures often affect multiple growth stages, including the vegetative growth stage, flowering stage, and boll formation stage. The temperature response mechanisms differ across these stages, making it difficult to distinguish the temperature response characteristics during the flower organ formation stage during breeding.
[0004] In the process of realizing the relevant breeding technology, the inventors of this application discovered that the above-mentioned prior art has at least the following technical problems: In the existing high-temperature resistant cotton screening method, the effect of high temperature cannot be directionally controlled on the formation of cotton flower organs and the pollination and fertilization stages, making it difficult to stably identify the high-temperature resistant response of different materials in the reproductive stage. Summary of the Invention
[0005] To overcome the above shortcomings, this invention provides a molecular breeding method for high-temperature resistant machine-harvested cotton, aiming to improve the problem in existing high-temperature resistant cotton screening methods where high temperature cannot be used to directionally control the formation of cotton flower organs and the pollination and fertilization stages, making it difficult to stably identify the high-temperature resistance response of different materials during the reproductive stage.
[0006] This invention provides the following technical solution: a molecular breeding method for high-temperature resistant machine-harvested cotton, comprising the following steps:
[0007] S1. Select cotton materials with compact plant type and concentrated boll opening phenotype as parent materials for machine harvesting traits, and select cotton materials with stable boll opening under high temperature conditions as high temperature resistant parent materials for hybridization to obtain F2 and segregating populations.
[0008] S2. When the separated population enters the early stage of initial flowering to full bloom, a high-temperature window treatment for flowering period is implemented. The high-temperature window treatment for flowering period is to locally raise the temperature of the fruit branch layer where the flowers open on that day, so that the temperature of the plant canopy reaches 38-45℃, the temperature rise time is 10-60 min, and it is maintained for 1-6 h, followed by a recovery time of 12-30 h. The treatment is repeated for 2-6 days or 2-6 times in total.
[0009] S3. After completing the flowering period directional high temperature window treatment, the plants treated with the flowering period directional high temperature window are subjected to machine harvesting vibration simulation screening treatment. The parameters of the machine harvesting vibration simulation screening treatment are: vibration frequency 2-15Hz, vibration displacement amplitude 5-60mm, single vibration duration 10-180s, and vibration number per plant 1-5 times.
[0010] S4. When the proportion of boll opening in the group reaches 20-60%, the plants that have undergone mechanical harvesting vibration simulation screening are subjected to simultaneous defoliation and boll opening screening treatment. The spray volume of the simultaneous defoliation-boll opening screening treatment is 150-600 L / ha, and the spray pressure is 0.2-0.6 MPa.
[0011] S5. Based on the combined screening results of the flower-stage directional high-temperature window treatment, the machine-harvesting vibration simulation screening treatment, and the leaf-blooming synchronous screening treatment, a high-temperature resistant machine-harvesting comprehensive selection index is constructed by a standardized index weighted calculation method, and target single plants or families are selected according to the high-temperature resistant machine-harvesting comprehensive selection index.
[0012] S6. The target single plant or family is continuously self-crossed or backcrossed to obtain high-temperature resistant machine-harvested cotton material.
[0013] Preferably, the flower-oriented high-temperature window treatment is limited to the period from the day the plant flowers to 2 days after flowering, and only the fruit branch layer where the flowers open on that day are locally heated.
[0014] Preferably, after the high-temperature window treatment during the flowering period, the plants are sorted from high to low according to the proportion of marked flowers forming young bolls, and only the plants in the top 10-50% of the population are retained for mechanical harvesting vibration simulation screening treatment.
[0015] Preferably, the machine-harvested vibration simulation screening process is performed at least once each in the pre-fibering stage and the fiber-opening stage.
[0016] Ideally, only plants that did not experience branch breakage after the directional high-temperature window treatment during flowering and the machine-harvested vibration simulation screening treatment are included in the simultaneous defoliation and boll opening screening treatment.
[0017] Preferably, after the simultaneous screening treatment of leaf defoliation and boll opening, only plants that complete the main boll opening process within 7-15 days and have a residual leaf rate of 10-40% are retained for the calculation of the comprehensive selection index for high-temperature resistant machine harvesting.
[0018] Preferably, the high-temperature resistant mechanical mining comprehensive selection index also includes:
[0019] Three categories of indicators were identified: flower-stage directional high-temperature window treatment indicators, machine-harvesting vibration simulation screening treatment indicators, and simultaneous defoliation-cotyl opening screening treatment indicators. Furthermore:
[0020] The weighting of the index for the directional high-temperature window treatment during flowering period was 0.40–0.70.
[0021] The total weight of the screening treatment index for machine harvesting vibration simulation and the screening treatment index for simultaneous defoliation and boll opening was 0.30–0.60.
[0022] The total weight of each indicator is 1.
[0023] Preferably, the heat window treatment auxiliary spray solution is applied 2–24 hours before and / or 2–24 hours after the directional high temperature window treatment during the flowering period.
[0024] Preferably, the heat window treatment auxiliary spraying solution comprises:
[0025] Trehalose 1-20 mM,
[0026] Spermine or its salt, 0.05–1.0 mM,
[0027] Proline 5-50 mM
[0028] Ascorbic acid or its salts, 0.5–10 mM,
[0029] The buffer system should be 2–20 mM with a pH of 5.5–7.0.
[0030] Nonionic surfactant 0.01–0.10%,
[0031] The remainder is water.
[0032] Preferably, in step S6, molecular marker detection is performed on the plants selected based on the comprehensive selection index for high-temperature resistance and machine harvesting, and the molecular marker results and the comprehensive selection index for high-temperature resistance and machine harvesting are used as selection criteria in subsequent generations.
[0033] The present invention has the following beneficial effects:
[0034] 1. This invention implements a directional high-temperature window treatment during the early flowering to full bloom stage of cotton, and locally raises the temperature of the fruiting branch layer where the flowers open on that day. This concentrates the high temperature effect on the flower organ formation and pollination and fertilization stages, thereby creating distinguishable differences in boll formation within the segregating population. This facilitates the early identification of materials that can complete the boll-forming process under high-temperature conditions in breeding, improving the selectivity of heat-resistant traits.
[0035] 2. This invention combines the results of targeted high-temperature window treatment during flowering, screening treatment based on machine harvesting vibration simulation, and screening treatment based on simultaneous defoliation and boll opening. It then constructs a comprehensive selection index for high-temperature machine harvesting tolerance, allowing for the evaluation of high-temperature boll-forming stability, mechanical vibration response stability, and boll opening synchronization within the same selection system. This ensures that the correlation between high-temperature tolerance and machine harvesting adaptability is synchronously fixed across generations, thus forming a cotton breeding method that combines high-temperature adaptability with mechanical harvesting adaptability.
[0036] 3. After completing the directional high-temperature window treatment during flowering, this invention employs a machine-harvesting vibration simulation screening process. Mechanical vibrations of a set frequency and displacement amplitude are applied to the plants, and screening is conducted before and during boll opening. This allows the fruit branch connection structure and boll stalk stability to be evaluated during the breeding stage. The differences in boll drop and branch breakage responses under mechanical vibration conditions can be identified during material selection, thereby obtaining cotton materials suitable for mechanical harvesting conditions. Attached Figure Description
[0037] Figure 1 This is a flowchart of a molecular breeding method for high-temperature resistant machine-harvested cotton proposed in this invention;
[0038] Figure 2 This is a flowchart illustrating the molecular breeding process of a high-temperature resistant machine-harvested cotton method proposed in this invention. Detailed Implementation
[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0040] Please refer to Figure 1 and Figure 2 This invention establishes a molecular breeding method for high-temperature resistant machine-harvested cotton. The following detailed description of this application is based on specific examples.
[0041] Example: Example 1:
[0042] (1) Test materials
[0043] Cotton material A, with its compact plant type, concentrated boll opening, and stable phenotype, was selected as the parent material for machine-harvested traits, while cotton material B, which maintained stable boll formation under continuous high-temperature planting conditions, was selected as the parent material for high-temperature resistant traits.
[0044] Hybridization was performed using artificial emasculation and pollination to obtain F1 generation materials. F1 generation materials were then self-pollinated to obtain F2 segregating populations. The F2 population was planted with 1200 plants per row, with a row spacing of 0.80m and a plant spacing of 0.15m.
[0045] (2) High temperature window treatment for flowering period orientation
[0046] Treatment was implemented when the population entered the initial flowering stage and the proportion of flowering plants reached approximately 30%.
[0047] A mobile covered heating shed was used for localized heating treatment, and temperature sensors were installed at a height of 30cm from the plant canopy.
[0048] The treatment parameters were as follows: canopy temperature: 42℃; heating time: 30min; holding time: 3h; recovery time: 18h; continuous treatment: 4d; 8 flowers that opened on each plant on the same day were selected and marked; the formation of young bolls was counted on the 10th day after the treatment ended.
[0049] (3) Screening and processing of machine mining vibration simulation
[0050] Mechanical vibration treatment is implemented using a clamping vibration device.
[0051] The clamping position is 25cm above the ground on the main stem.
[0052] The vibration parameters are as follows: vibration frequency: 8Hz; displacement amplitude: 25mm; single duration: 60s;
[0053] Vibration frequency per plant: 3 times; once 10 days before boll opening and once when the boll opening rate is about 40%, and the number of bolls falling and the number of broken branches are recorded before and after vibration.
[0054] (4) Simultaneous screening treatment for leaf defoliation and boll opening
[0055] Spraying treatment should be carried out when the proportion of fluffy particles in the group reaches about 35%.
[0056] The spraying conditions were as follows: spray volume: 350 L / ha; spray pressure: 0.35 MPa.
[0057] The boll-opening process was statistically analyzed on the 7th and 12th days after treatment.
[0058] Select plants that complete the main boll opening process within 12 days and have a residual leaf rate of 25%.
[0059] (5) Construction of a comprehensive selection index for high-temperature mechanical mining
[0060] The following indicators were standardized: the proportion of young flower and boll formation, the boll drop rate after vibration treatment, the occurrence of branch breakage, the time of boll opening completion, and the residual leaf rate, using the Min–Max standardization method:
[0061] ;
[0062] Weights were set as follows: flowering period directional high temperature window treatment index: 0.55; machine harvesting vibration simulation screening treatment index: 0.30; simultaneous defoliation and boll opening screening treatment index: 0.15; calculate the comprehensive index and sort by value, retaining the top 30% of plants.
[0063] (6) Preparation and use of heat window treatment auxiliary spray solution
[0064] Weigh out: trehalose 10mM; spermidine 0.3mM; proline 20mM; ascorbic acid 3mM;
[0065] 10 mM MES buffer (pH 6.2), Tween-20 0.05% (v / v), add deionized water to a final volume of 10 L, stir magnetically for 15 min at 25 °C, and spray once 12 h before the high-temperature window treatment, at a rate of 300 L / ha.
[0066] (7) Offspring fixed
[0067] 100 mg of young leaves were collected from the selected plants for DNA extraction, with the DNA concentration controlled at 50 ng / μL. SNP molecular markers associated with heat tolerance and boll retention rate and / or machine harvesting adaptability were selected for genotyping. These SNPs could be derived from reported heat tolerance-related QTL / candidate gene regions, or significant sites obtained through linkage / association analysis based on the phenotypic data of this F2 population.
[0068] SNP genotyping can be performed using methods such as KASP, HRM, or targeted sequencing. The presence of favorable alleles is determined based on the genotype at each locus, and a molecular score is generated based on the carrying status of favorable alleles. This molecular score is combined with a comprehensive selection index for heat tolerance in mechanical harvesting as the selection criterion. Plants carrying favorable alleles and with a higher comprehensive index are preferentially retained and self-pollinated to the F4 generation to achieve trait fixation.
[0069] Example 2: Except for the following parameters, the remaining steps are the same as in Example 1. Flowering period directional high-temperature window treatment parameters: canopy temperature: 38℃; heating time: 10min; holding time: 1h; continuous treatment: 2d; machine harvesting vibration simulation screening treatment: vibration frequency: 2Hz; displacement amplitude: 5mm; vibration time: 10s; number of vibrations: 1; defoliation treatment spray volume: 150L / ha. The trehalose concentration in the auxiliary spray solution is 1mM.
[0070] Example 3: Except for the following parameters, the remaining steps are the same as in Example 1.
[0071] High-temperature window treatment parameters for flowering period orientation: Canopy temperature: 45℃; Heating time: 60 min; Holding time: 6 h; Continuous treatment: 6 d;
[0072] Mechanical vibration simulation screening process: vibration frequency: 15 Hz; displacement amplitude: 60 mm; vibration time: 180 s; number of vibrations: 5.
[0073] Defoliation treatment spray volume: 600 L / ha.
[0074] The auxiliary spray solution contains: trehalose 20 mM; spermidine 1.0 mM; proline 50 mM; ascorbic acid 10 mM.
[0075] Comparative Example: Comparative Example 1
[0076] F2 segregating populations were constructed using the same parental materials A and B as in Example 1, with the same population size and planting method. During the initial flowering to full bloom stage, no artificial heating was applied; the populations were grown only under natural ambient temperature conditions.
[0077] When the natural highest daily temperature of the season reaches 37-40℃, record the flowering and boll-forming situation.
[0078] No mechanical mining vibration simulation screening process was implemented.
[0079] When the percentage of fluffy leaves that have opened reaches approximately 35%, the fluffing process and the condition of any remaining leaves are recorded directly.
[0080] No comprehensive selection index for high-temperature resistant machine harvesting was constructed; selection was based solely on the number of bolls present on each plant, with the top 30% of plants retained for offspring fixation.
[0081] Comparative Example 2
[0082] The same population size and planting method as in Example 1 were used. No high-temperature window treatment for flowering was applied during the initial flowering to full bloom stage.
[0083] Mechanical harvesting vibration simulation screening was carried out before and during the boll opening stage, with the same parameters as in Example 1: vibration frequency 8 Hz; displacement amplitude 25 mm; duration 60 s; 3 times per plant; when the boll opening ratio reached about 35%, simultaneous defoliation and boll opening screening was carried out, with a spray volume of 350 L / ha and a spray pressure of 0.35 MPa.
[0084] A comprehensive selection index for high-temperature resistant mechanized harvesting was constructed, but it did not include the high-temperature window treatment index for flowering period. The index was constructed only by screening treatment indexes based on mechanized harvesting vibration simulation and simultaneous screening treatment indexes for leaf defoliation and boll opening.
[0085] Comparative Example 3
[0086] The same population size and planting method as in Example 1 were used.
[0087] During the initial flowering to full bloom stage, a directional high-temperature window treatment was implemented, with parameters consistent with those in Example 1:
[0088] Canopy temperature 42℃; heating for 30 min; holding for 3 h; continuous for 4 days;
[0089] No mechanical mining vibration simulation screening process was implemented.
[0090] When the boll opening rate reaches approximately 35%, a simultaneous screening process involving leaf defoliation and boll opening is implemented.
[0091] A comprehensive selection index for high-temperature resistant mechanical mining is constructed, but it does not include the screening and treatment index for mechanical mining vibration simulation.
[0092] Comparative Example 4
[0093] The same population size and planting method as in Example 1 were used.
[0094] Implement targeted high-temperature window treatment during the flowering period from the initial flowering stage to full bloom.
[0095] Mechanical mining vibration simulation screening was carried out before and during the fibrous opening stage.
[0096] Simultaneous screening treatment for leaf defoliation and boll opening was not implemented.
[0097] A comprehensive selection index for high-temperature resistant mechanized harvesting was constructed, but it does not include the simultaneous screening treatment index for defoliation and boll opening.
[0098] Performance testing
[0099] I. Target of Testing
[0100] The test samples came from the following sources:
[0101] The F4 stable families obtained from screening in Example 1; the F4 stable families obtained from screening in Example 2; the F4 stable families obtained from screening in Example 3; the F4 families obtained from screening in Comparative Example 1; the F4 families obtained from screening in Comparative Example 2; the F4 families obtained from screening in Comparative Example 3; the F4 families obtained from screening in Comparative Example 4; three representative families were selected for each type of material, and 30 plants were randomly selected from each family as test samples.
[0102] II. Detection Methods
[0103] (1) Determination of high temperature boll retention rate
[0104] A high-temperature environment was set in an artificially controlled greenhouse: maximum daily temperature: 40℃; duration: 5 days; relative humidity: 55%; 10 flowers were marked on the day of flowering; the number of young bolls formed was counted after 10 days. Calculation formula: ;
[0105] (2) Measurement of the ring-falling rate due to mechanical vibration
[0106] The plants were treated with a vibration frequency of 8 Hz, a displacement amplitude of 25 mm, and a duration of 60 s.
[0107] The change in the number of bells before and after vibration was statistically analyzed.
[0108] ;
[0109] (3) Determination of branch breakage rate
[0110] After vibration treatment, the number of plants with broken main stems or primary fruit branches was counted. ;
[0111] (4) Determination of the concentration of fluff release
[0112] The percentage of boll opening was statistically analyzed on the 7th, 10th, and 14th days after defoliation treatment.
[0113] Calculate the cotton-blooming concentration index: ;
[0114] III. Test Results
[0115] Source of materials Boll retention rate (%) Example 1 78.4 Example 2 65.2 Example 3 80.1 Comparative Example 1 52.3 Comparative Example 2 54.8 Comparative Example 3 76.9 Comparative Example 4 77.5
[0116] Table 1. High-Temperature Boll Retention Rate (%)
[0117] Source of materials Ringing rate (%) Example 1 8.6 Example 2 12.3 Example 3 7.9 Comparative Example 1 18.7 Comparative Example 2 9.5 Comparative Example 3 21.4 Comparative Example 4 10.1
[0118] Table 2. Ring dropping rate due to mechanical vibration (%)
[0119] Source of materials Branch breakage rate (%) Example 1 2.1 Example 2 3.8 Example 3 1.9 Comparative Example 1 6.7 Comparative Example 2 4.5 Comparative Example 3 7.2 Comparative Example 4 4.3
[0120] Table 3. Branch breakage rate (%)
[0121] Source of materials Concentration Index Example 1 0.88 Example 2 0.8 Example 3 0.9 Comparative Example 1 0.62 Comparative Example 2 0.64 Comparative Example 3 0.66 Comparative Example 4 0.7
[0122] Table 4. Fluff Concentration Index
[0123] IV. Data Analysis
[0124] Combining Examples 1-3 with Comparative Example 1, it can be seen that under artificial high temperature conditions, the boll retention rate of the materials in the Examples is significantly higher than that in Comparative Example 1, indicating that the directional high temperature window treatment during flowering has an impact on the boll stability under high temperature conditions.
[0125] Combining Examples 1-3 with Comparative Example 3, it can be seen that under mechanical vibration conditions, the boll drop rate and branch breakage rate of the materials in the examples are lower than those of the materials that have not undergone mechanical harvesting vibration simulation screening treatment, indicating that mechanical harvesting vibration simulation screening treatment has a screening effect on plant structural stability.
[0126] Combining Examples 1-3 with Comparative Example 4, it can be seen that the boll opening concentration index of the materials in the examples is higher than that of the materials that have not undergone simultaneous defoliation and boll opening screening treatment, indicating that simultaneous defoliation-boll opening screening treatment has an impact on maturity uniformity.
[0127] The results in Tables 1 to 4 show that Examples 1 to 3 exhibited differences in boll retention rate, boll drop rate, branch breakage rate, and boll opening concentration index, while the pairs only showed differences in some indicators. This indicates that the three-stage screening process achieved a combined screening effect on multiple traits.
[0128] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A molecular breeding method for high-temperature resistant machine-harvested cotton, characterized in that, Includes the following steps: S1. Select cotton materials with compact plant type and concentrated boll opening phenotype as parent materials for machine harvesting traits, and select cotton materials with stable boll opening under high temperature conditions as high temperature resistant parent materials for hybridization to obtain F2 and segregating populations. S2. When the separated population enters the early stage of initial flowering to full bloom, a high-temperature window treatment for flowering period is implemented. The high-temperature window treatment for flowering period is to locally raise the temperature of the fruit branch layer where the flowers open on that day, so that the temperature of the plant canopy reaches 38-45℃, the temperature rise time is 10-60 min, and it is maintained for 1-6 h, followed by a recovery time of 12-30 h. The treatment is repeated for 2-6 days or 2-6 times in total. The flower-oriented high-temperature window treatment is limited to the period from the day the plant flowers to 2 days after flowering, and only the fruit branch layer where the flower is on the day of flowering is locally heated. S3. After completing the flowering period directional high temperature window treatment, the plants treated with the flowering period directional high temperature window are subjected to machine harvesting vibration simulation screening treatment. The parameters of the machine harvesting vibration simulation screening treatment are: vibration frequency 2-15Hz, vibration displacement amplitude 5-60mm, single vibration duration 10-180s, and vibration number per plant 1-5 times. Only plants that did not experience branch breakage after the directional high-temperature window treatment during flowering and the machine-harvested vibration simulation screening treatment were selected for simultaneous defoliation and boll opening screening treatment. S4. When the proportion of boll opening in the group reaches 20-60%, the plants that have undergone mechanical harvesting vibration simulation screening are subjected to simultaneous defoliation and boll opening screening treatment. The spray volume of the simultaneous defoliation-boll opening screening treatment is 150-600 L / ha, and the spray pressure is 0.2-0.6 MPa. S5. Combined screening results based on flowering period directional high temperature window treatment, machine harvesting vibration simulation screening treatment, and defoliation-fiber opening synchronous screening treatment. The high-temperature resistant mechanical mining comprehensive selection index also includes: Three categories of indicators: flowering period directional high temperature window treatment index, machine harvesting vibration simulation screening treatment index, and defoliation-fiber opening synchronous screening treatment index. A comprehensive selection index for high-temperature resistant machine harvesting is constructed by weighting standardized indicators, and target individual plants or families are selected based on the comprehensive selection index for high-temperature resistant machine harvesting. S6. The target single plant or family is continuously self-crossed or backcrossed to obtain high-temperature resistant machine-harvested cotton material.
2. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, After the high-temperature window treatment during the flowering period, the plants were sorted from high to low according to the proportion of marked flowers forming young bolls, and only the top 10-50% of the plants in the group were retained for mechanical harvesting vibration simulation screening treatment.
3. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, The machine-harvesting vibration simulation screening process is implemented at least once each in the pre-blooming stage and the blooming stage.
4. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, After the simultaneous screening treatment of leaf defoliation and boll opening, only plants that complete the main boll opening process within 7-15 days and have a residual leaf rate of 10-40% are retained for the calculation of the comprehensive selection index for high-temperature resistant machine harvesting.
5. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, The weight of the index for the flower-stage directional high-temperature window treatment is 0.40–0.
70. The total weight of the screening treatment index for machine harvesting vibration simulation and the screening treatment index for simultaneous defoliation and boll opening was 0.30–0.
60. The total weight of each indicator is 1.
6. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, Apply the heat window treatment auxiliary spray solution 2–24 hours before and / or 2–24 hours after the directional high temperature window treatment during the flowering period.
7. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 6, characterized in that, The heat window treatment auxiliary spraying solution includes: Trehalose 1-20 mM, Spermine or its salt, 0.05–1.0 mM, Proline 5-50 mM Ascorbic acid or its salts, 0.5–10 mM, The buffer system should be 2–20 mM with a pH of 5.5–7.
0. Nonionic surfactant 0.01–0.10%, The remainder is water.
8. The molecular breeding method for high-temperature resistant machine-harvested cotton according to claim 1, characterized in that, In step S6, molecular marker detection is performed on the plants selected based on the comprehensive selection index for high-temperature resistance and machine harvesting, and the molecular marker results and the comprehensive selection index for high-temperature resistance and machine harvesting are used as selection criteria in subsequent generations.