Method for identifying and screening superior germplasm of rape plant canopy leaf and application
By screening and introducing materials with excellent sessile leaf area and functional duration of rapeseed canopy leaves, the problem of sessile leaves being neglected in rapeseed breeding was solved, and photosynthetic efficiency and yield were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- OIL CROPS RES INST CHINESE ACAD OF AGRI SCI
- Filing Date
- 2026-02-26
- Publication Date
- 2026-04-21
AI Technical Summary
In rapeseed breeding, existing technologies have neglected the importance of the sessile leaves on the main stem of the rapeseed plant, resulting in low photosynthetic efficiency and limited yield improvement.
By measuring and screening key trait indicators of rapeseed canopy leaves, especially the area and functional duration of sessile leaves, a scientific and efficient identification and screening method is provided. This method selects sessile leaf materials with excellent area and green retention, and introduces them into breeding parents to improve canopy photosynthetic capacity.
It significantly increased the number of branches and pods, improved the yield of individual plants and the overall yield of the plant population, and achieved a significant increase in rapeseed yield.
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Figure CN121899342A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of agricultural genetics and breeding technology, specifically relating to a method and application for identifying and screening dominant germplasm in the canopy leaves of rapeseed plants. Background Technology
[0002] Rapeseed is an important oilseed crop worldwide. Low-erucic acid rapeseed oil has a low content of unsaturated fatty acids and an oleic acid content as high as 60%, with a scientifically balanced fatty acid composition. Through a series of studies in recent years, it has been widely recognized as one of the healthiest bulk edible oils (Wang Kang, Yang Jing, Yue Peilei, et al., 2025). Improving rapeseed yield and promoting rapeseed oil production capacity is of great significance for ensuring edible oil supply and improving people's quality of life (Li Jiahui, Li Liangliang, Zhao Jia, et al., 2025; Feng Haitang, Wang Hanzhong; 2024).
[0003] Leaves are the main photosynthetic organs of rapeseed during the seedling and flowering stages. Their morphogenesis and spatial distribution directly determine the light interception efficiency, assimilate allocation pattern, and final yield potential. Rapeseed leaves are generally classified into three categories according to developmental stage: basal rosette leaves (also called long-petioled leaves, which function during the vegetative growth stage of rapeseed), Figure 1 A); Short-petioled leaves on the main stem (acting from bolting stage to early silique stage, Figure 1 B); the sessile leaves on the upper part of the main stem (effective from flowering to silique stage). Figure 1 C).
[0004] In gramineous crops like rice, wheat, and corn, the upper leaves (flag leaves and sword leaves) have a significantly larger leaf area compared to the lower leaves, making them important targets for breeding improvement. However, in rapeseed, the leaf area of the leaves on the main stem gradually decreases from bottom to top. Generally, sessile leaves have a smaller leaf area and shorter green period compared to long-petioled and short-petioled leaves, and their function is often overlooked in rapeseed breeding improvement, sometimes being mistakenly considered "senescent redundant organs." Rapeseed primary branches develop from axillary buds on the main stem. The leaves that enclose these axillary buds are mostly sessile leaves and a few upper short-petioled leaves. These leaves form the canopy of the rapeseed plant from the initial flowering stage to the silique stage, receiving direct sunlight and serving as the main photosynthetic organs during this stage, playing a crucial role in branching, silique development, and grain formation.
[0005] During the developmental stage to the pod-forming stage of rapeseed plants, the area of canopy leaves, especially sessile leaves, decreases by more than 50% compared to rosette leaves and short-stalked leaves at the lower part of the main stem, indicating significant room for improvement. Appropriately increasing the area of canopy leaves and their functional duration is an effective way to improve the photosynthetic capacity of the rapeseed canopy and is undoubtedly a key route for further high-yield breeding of rapeseed. Summary of the Invention
[0006] The purpose of this invention is to provide a scientific and efficient method for identifying and screening dominant germplasm in the canopy leaves of rapeseed plants. By measuring and obtaining key trait indicators of canopy leaves from the initial flowering stage to the pod-bearing stage of rapeseed plants grown in the field or indoors, the invention proposes key screening and definition criteria for dominant germplasm in rapeseed canopy leaves and provides a technical path for improving the canopy layer of rapeseed breeding parents to enhance their overall photosynthetic capacity.
[0007] Another objective of this invention is to provide an application of the aforementioned screening method in rapeseed breeding, which combines area and functional duration to introduce canopy leaf advantages into the backbone parents to improve the current main cultivated varieties. Compared with the original recipient rapeseed material, the branching becomes more robust, the number of siliques on branches increases, the number of branches also increases, and the yield per plant and the yield per population both increase significantly.
[0008] To achieve the above objectives, the present invention provides the following technical solution: The technical concept of this invention is as follows: By removing the sessile leaves of several major rapeseed varieties during the budding stage, yield measurement and variety evaluation experiments were conducted, clarifying that the contribution effect of sessile leaves on rapeseed grain yield is approximately 15%. Further investigation was conducted on traits such as the area of sessile leaves in rapeseed germplasm resource populations. Sessile leaf removal experiments were carried out on nine identified materials with different types of sessile leaf areas (3 with larger sessile leaf areas, 3 with sessile leaf areas similar to Zhongshuang 11 (ZS11), and 3 with smaller sessile leaf areas). Analysis of yield measurement and variety evaluation data revealed that sessile leaf removal led to a yield reduction of 2.47-39.36%, with an average of 17.07%. The larger the sessile leaf area, the greater the yield reduction effect. Based on correlation analysis with key yield traits, this invention clarified that the reduction in the number of branch pods is the only correlated factor leading to yield decline due to sessile leaf removal treatment. Based on this, it was concluded that sessile leaves mainly promote branching and branch pod development, i.e., they directly contribute to yield.
[0009] The sessile leaves and their adjacent short-petioled leaves form the canopy leaves during the flowering and early silique stages of rapeseed. They receive direct sunlight within the plant population and exhibit a significant advantage in photosynthetic capacity compared to the sessile and long-petioled leaves at the base of the main stem, primarily promoting branching and elongation. Therefore, in a first aspect, this invention provides a method for identifying and screening dominant germplasm in the canopy leaves of rapeseed plants, comprising the following steps: (1) The first sessile leaf and the adjacent upper short petiole leaf of the rapeseed plant planted in the field or greenhouse were used as representative leaves. The investigation method of the key traits of the representative leaves was clarified. The main investigations were on leaf length, width and leaf area. (2) The method for determining the functional duration of the above-mentioned representative leaves of the canopy was clarified. The time points of canopy leaf development and growth were recorded from the budding stage to the mid-flowering stage. The time points of leaf apoptosis from green to yellow were observed regularly during the silique stage. When necessary, the chlorophyll content was measured to judge the senescence of the canopy leaves. The senescence time points of the canopy leaves were recorded, and the functional duration of the canopy leaves was statistically obtained. (3) Based on the statistical analysis of the survey data of the canopy leaves of the breeding materials and germplasm resources in the early stage, the screening and identification criteria for the dominant sessile leaf germplasm of rapeseed canopy leaves were defined. The sessile leaves of the first leaf position of the candidate materials were compared with the control "Zhongshuang 11" and other current main reference varieties. The sessile leaf area exceeding 50% was defined as the dominant germplasm. The sessile leaf functional duration exceeding 20% of the current main reference varieties such as "Zhongshuang 11" and "Zhongyouza 39" or the sessile leaves remaining green until two weeks before the maturity of the rapeseed pods were defined as the sessile leaf functional duration dominant germplasm. According to the contribution effect of sessile leaves on yield, it is estimated that the sessile leaf area exceeding 50% or the greenness exceeding 20% can increase the yield by more than 5%, which has considerable breeding utilization value.
[0010] Optionally, the rapeseed refers to rapeseed crops used for field or greenhouse cultivation to produce edible oil, mainly including Brassica napus, Brassica rapa, and Brassica juncea; the germplasm includes germplasm resources and breeding population materials of various types of crops.
[0011] Optionally, the canopy leaves refer to the upper leaves of the main stem of rapeseed from the initial flowering stage to the silique stage. They mainly include all the sessile leaves on the main stem of the rapeseed plant and about three short-stalked leaves at the top, which play an important role in the branching and silique development of densely planted rapeseed plants in the field or indoors.
[0012] Optionally, the method for determining the canopy leaf area involves taking a live photograph or photographing a detached leaf (such as the first sessile leaf or the uppermost short-stalked leaf immediately adjacent to this sessile leaf). Key trait data, such as leaf length, width, and leaf area, of different individual plants of the material are obtained using a commercial leaf analysis system.
[0013] Optionally, the method for statistical analysis of canopy leaf function duration is as follows: record the development, growth, and unfolding time of representative canopy leaves (such as the first sessile leaf or the uppermost short-stalked leaf immediately adjacent to this sessile leaf), record the leaf color of the canopy leaves from normal green to yellow by visual observation, and further, detect changes in chlorophyll content in the same canopy leaf to determine the senescence of the canopy leaves, record the senescence time of the canopy leaves, and statistically analyze the canopy leaf function duration.
[0014] Optionally, the method for identifying and screening dominant germplasm of canopy leaves prioritizes the use of the first sessile leaf, and may also combine it with the short petiole leaves at the uppermost part of the main stem if necessary.
[0015] A second aspect of this invention provides an application of the aforementioned identification and screening method in rapeseed breeding or canopy improvement of rapeseed breeding parents. Using the aforementioned method, dominant canopy leaf germplasm obtained through screening and identification is introduced into rapeseed breeding materials or parents through 3-5 generations of continuous hybridization, thereby improving the canopy leaves and optimizing the canopy plant type to increase yield. Compared to the original recipient rapeseed material, the branches become more robust, the number of siliques on branches increases, and the number of branches also increases, resulting in a significant increase in both individual plant and population yield.
[0016] The beneficial effects of this invention are as follows: This invention utilizes two selected canopy leaf dominant germplasms and the “Zhongshuang 11” rapeseed backbone breeding parents to conduct hybridization and backcrossing experiments. Based on the above-mentioned canopy leaf dominant identification method, canopy leaf dominant is detected and tracked, and a near-isotropic line material (BC2F2 family) with canopy leaf dominant of Zhongshuang 11 was constructed. Furthermore, an investigation and research were conducted on indicators such as sessile leaf area and yield per plant.
[0017] This invention clarifies that canopy improvement during the flowering and pod-forming stages of rapeseed plants is a feasible approach to increasing rapeseed yield. This invention also provides important references in terms of research ideas and technical methods for the subsequent genetic analysis of superior canopy leaf traits and the development of molecular breeding tools. Attached Figure Description
[0018] Figure 1 To cultivate "Zhongshuang 11" rapeseed in the cultivation room; A. rapeseed plant, B. long-petioled leaves (roselet leaves), C. short-petioled leaves, D. sessile leaves.
[0019] Figure 2 Photographs of sessile leaf (RSL) material and untreated (CK) material.
[0020] Figure 3 This is a schematic diagram of a live photograph of a sessile leaf at the first leaf position.
[0021] Figure 4 Data on the cultivation of 6 varieties of materials at the Yangluo experimental base were obtained by removing sessile leaves and removing untreated materials.
[0022] Figure 5 A schematic diagram for measuring the length, width, and area of the first sessile leaf and the uppermost short-stalked leaf of a natural population material.
[0023] Figure 6 To measure the frequency distribution histogram of the first leaf position of the sessile leaf in natural population materials.
[0024] Figure 7 A graph showing the correlation between the area of the first sessile leaf at the first leaf position and the yield reduction effect for nine materials.
[0025] Figure 8 Image for screening F2 single plants with excellent canopy leaf area.
[0026] Figure 9 This image shows a selection of F2 plants with excellent canopy leaf area and functional duration. Detailed Implementation
[0027] Unless otherwise specified, the specific implementation of the technical solution described in this invention uses the conventional planting method for winter rapeseed in the Yangtze River Basin, which involves sowing between September 20 and October 10 each year at a density of 20,000 plants per mu.
[0028] Example 1: Experiment on the removal of sessile leaves in rapeseed varieties clearly demonstrates the significant contribution of sessile leaves to rapeseed yield. To preliminarily explore the contribution effect of sessile leaves on yield, the applicant planted multiple representative rapeseed germplasm materials of different types at the Wuchang and Yangluo experimental bases of the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences from September 2024 to May 2025 (winter rapeseed growth cycle). Specific materials included: conventional varieties Zhongshuang 11 and G142 (Zheyou 50); hybrid varieties Zhongyouza 39 and Zhongyouza 501; and backbone parent materials P8033 and 19AT637. P8033 and 19AT637 are both pure rapeseed lines obtained through multi-parental hybridization, high-yield, high-quality, and multi-resistance phenotypic identification and screening, and microspore double haploid technology, serving as parents to multiple rapeseed hybrids such as Zhongyouza 39 and Zhongyouza 501. The materials were planted in three replicates, with each replicate consisting of 10 rows (3 rows per meter, 1.8-meter bed). During the budding stage of different rapeseed varieties, remove 5 rows of tender, sessile leaves from the entire rapeseed plant, leaving the remaining 5 rows untreated. Figure 2 To illustrate the material condition at flowering time after the removal of sessile leaves during the experiment, CK represents the control material, and RSL represents the material with sessile leaves removed. The length, width, and area of sessile leaves were investigated during flowering, as follows: A1) Sampling location: the first sessile leaf of rapeseed; A2) Sample size: Select sessile leaves from 10 individual plants; A3) Sampling method: Cut the leaf from the petiole near the main stem; A4) Instruments and conditions for measurement: black screen, ruler, and mobile phone for taking pictures; A5) Measurement method: In vitro photography: Each leaf is laid flat on a black cloth and photographed with a mobile phone, with the phone's camera aligned with the cloth; In vivo photography (e.g., ... Figure 3Without damaging the rapeseed leaves, the rapeseed plant leaves were placed together with the background and photographed with a mobile phone. The photos were then used in computer software (Wanshen LA-S Leaf Area Analysis System) to calculate the length, width and leaf area of the sessile leaves. A6) The measured parameters include: length, width, and leaf area of sessile leaves.
[0029] The production measurement operation steps are as follows: When the rapeseed pods mature, all individual plants in a single row are harvested together, threshed, dried, and then the seeds are weighed.
[0030] Weigh the dry weight of the grains in a single row using an electronic balance and record it as W (unit: kg).
[0031] The yield of the 5-row area needs to be converted into yield per mu (unit of land area) or hectare. The core formula is as follows: Y = W / (L × D) × 10000 / 1000 The parameters in the formula are explained as follows: Y: yield per hectare of the target variety (unit: t / hectare); W: dry weight of grain per row (unit: kg); L: effective harvest length per row (unit: m); D: row spacing set in the experiment, 0.33 meters; 10000: conversion factor between hectares and square meters. W / (L × D) is the yield per square meter calculated from the conversion.
[0032] Results Analysis: Table 1 and others Figure 4 As shown, Zhongshuang 11 is ZS11, Zhongyouza 39 is ZYZ39, and Zhongyouza 501 is ZYZ501; CK represents the treated material; RSL represents the material after removing the sessile leaves. Removing the sessile leaves significantly reduced yield. Specifically, at the Yangluo experimental base, Zhongshuang 11 experienced a 11.84% yield reduction after removing the sessile leaves, 19AT637 a 17.49% reduction, Zhongyouza 39 a 14.96% reduction, P8033 a 17.81% reduction, Zhongyouza 501 a 18.37% reduction, and G142 a 23.05% reduction. In the Wuchang experimental base, the yield of rapeseed variety Zhongshuang 11 decreased by 12.05% after the removal of sessile leaves; 19AT637 decreased by 6.86%; Zhongyouza 39 decreased by 12.35%; P8033 decreased by 9.54%; Zhongyouza 501 decreased by 23.72%; and G142 decreased by 14.01%. It is clear that the contribution effect of sessile leaves on rapeseed grain yield is approximately 15%. Statistical significance tests: p<0.001(***), p<0.01(**), p<0.05(*).
[0033] In 2022-2023 and 2023-2024, the inventors also conducted sessile leaf removal experiments on representative materials such as Zhongshuang 11, Zhongyouza 19, and Zhongyouza 39 at the Wuhan Yangluo Experimental Base, and obtained the same results as above.
[0034] Table 1. Length, width, and area of the first sessile leaf at the Wuchang and Yangluo experimental bases, and experimental yield data. Example 2: Analysis of the differences in canopy leaves between natural populations and breeding material populations Rapeseed populations: Using 300 domestic and international natural population resources (Wang N et al., 2025) from the Rapeseed Genetics and Breeding Innovation Team of the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, as well as breeding material populations, the differences in canopy leaves between natural populations and breeding material populations were determined using the same method as shown in Example 1, which measured the first sessile leaf position. The differences in canopy leaf area between these materials were clarified by measuring the length, width, and area of the first sessile leaf position, as well as the length, width, and area of the uppermost short-stalked leaf.
[0035] Results analysis: such as Figure 5 As shown, the length, width, and area of the first sessile leaf and the length, width, and area of the uppermost short-stalked leaf were quickly measured. Figure 5 The red box in the middle shows a schematic diagram of short-petioled leaves, and the rest are schematic diagrams of sessile leaves. Each leaf contains data on leaf length, width, and area. The difference between the short-petioled leaves (length, width, and area) of rapeseed and the canopy leaves of the sessile leaf natural population and breeding material population is consistent. That is, the first sessile leaf of rapeseed can be used as the representative leaf of the rapeseed plant canopy during the initial flowering stage to the pod-bearing stage. Figure 6 The image shows a histogram of the distribution frequency of the sessile leaf area at the first leaf position in both natural and breeding populations. The inventors expressed the canopy leaf area as the sessile leaf area at the first leaf position, with differences ranging from 8.7 to 149.6 cm². 2 Currently, the area of sessile leaves in the main cultivated varieties is mostly at a medium or small level (Table 1), indicating a huge potential for improvement in sessile leaves.
[0036] Example 3: Conducting an experiment on removing sessile leaves from extreme materials in natural canopy forests to determine the yield reduction caused by sessile leaves. Similar to Example 1, nine materials with different sessile leaf areas (Type A: 3 with larger sessile leaf areas; Type B: 3 with sessile leaf areas similar to Zhongshuang 11; Type C: 3 with smaller sessile leaf areas) were planted in the field at the Yangluo experimental base. A whole-plant sessile leaf removal experiment was conducted during the budding stage of these nine materials. The length, width, and area of the first leaf position sessile leaf were measured, and related data were used for yield estimation.
[0037] Results analysis: As shown in Table 2 and Figure 7As shown, sessile leaf removal experiments were conducted on nine materials. Analysis of yield measurement and variety evaluation data revealed that sessile leaf removal led to yield reductions ranging from 2.47% to 39.36%, with an average of 17.07%. The larger the sessile leaf area, the greater the yield reduction effect after leaf removal; the two were significantly correlated, and R... 2 It is 0.5879.
[0038] Table 2 shows the sessile blade area and related yield data for the nine materials. Example 4: A method for screening and identifying dominant germplasm in canopy leaves Rapeseed populations: 300 natural populations and breeding materials from home and abroad (Wang N et al., 2025) Filter the above data 1) Screening materials with excellent canopy leaf area Selection period: peak flowering period; Target species: sessile leaves at the first leaf position; Screening criteria: sessile leaf length, sessile leaf width, and sessile leaf area; Reference variety: Zhongshuang 11 Methods: The first sessile leaf of the candidate material and the control variety at full bloom were photographed. The area was compared using the Wanshen LA-S leaf area analysis system. The length, width, and area of the sessile leaves of the candidate material and the control variety at full bloom were measured. Materials with an average first sessile leaf area greater than 50% of the average area of the control variety were considered to have superior canopy leaf area. 2) Screening for materials with excellent canopy leaf function duration Selection period: flowering period, silique stage; Target species: sessile leaves at the first leaf position; Screening criteria: Leaf color change characteristics and SPAD value observed by human visual inspection; Reference variety: Zhongshuang 11 Methods: Preliminary observations were conducted on the sessile leaves during the flowering period of rapeseed materials and control varieties to determine the development time of the first sessile leaf. The first sessile leaf during the pod-setting stage was also observed. When the leaf color clearly changed from green to yellow by visual inspection, and the SPAD value was measured using a SPAD-502 instrument, significant senescence of the canopy leaves was indicated by a SPAD value below 25. This time point was recorded. The duration of sessile leaf function in the candidate materials and the control varieties from flowering to pod-setting was determined. Materials with an average sessile leaf function duration exceeding the control variety's average by more than 20% (more than two weeks) were considered superior in canopy leaf function duration. A few materials with exceptionally long sessile leaf greenness, only turning yellow two weeks before pod maturity, were also identified in the breeding population. These materials were directly positioned as superior in sessile leaf function duration.
[0039] Table 3 shows the criteria for judging the function of canopy blades. The specific steps for measuring the length, width, and area of the canopy leaves are the same as those for investigating the length, width, and area of sessile leaves during the flowering period in Example 1.
[0040] The specific steps for determining the duration of canopy leaf function include: A1) Location: The first sessile leaf of rapeseed; A2) Sample size: Select sessile leaves from 10 individual plants; A3) Measuring instruments and conditions: SPAD-502 chlorophyll meter; A4) Measurement method: Observe and determine the development time of the first leaf sessile leaf during the flowering period; record the data; observe the first leaf sessile leaf during the silique stage. When the visual characteristics of the leaf are obviously yellow and green, measure the SPAD value of the first leaf sessile leaf of 10 rapeseed plants 3 times with SPAD-502. When the SPAD value is lower than 25, the canopy leaves are senescent. Record the time point. A5) The measurement indicators include: SPAD value; and observation of leaf color change characteristics.
[0041] By measuring the area and functional duration of representative leaves (first leaf position, sessile leaves) in the canopy of rapeseed plants from the initial flowering stage to the pod-forming stage, specifically by rapidly measuring the leaf length, leaf width, and leaf area of sessile leaves, and accurately identifying their developmental and senescence time points, superior canopy leaf materials were selected.
[0042] Results Analysis: The area of representative leaves (first sessile leaves) in the canopy of rapeseed plants from the initial flowering stage to the pod-forming stage was measured. The leaf length, width, and area of the sessile leaves were quickly determined to screen for materials with excellent canopy leaf area. Statistical analysis of the data ultimately selected 10 materials with excellent canopy leaf area, as shown in Table 4.
[0043] Table 4 shows the length, width, and area of the first sessile leaf in 10 materials with excellent canopy leaf area.
[0044] Example 5: An improved method for screening and identifying the dominance of sessile leaves in rapeseed canopy, applied to the rapeseed parent variety Shuang 11. The selected materials were hybridized to introduce superior canopy leaf area and functional duration materials into the ZS11 variety. Repeated backcrossing resulted in the high-generation backcross population BC2F2. Using the two screening methods described above, superior introduced individual plants were quickly selected, reducing the breeding scale and rapidly and efficiently improving the canopy leaves of currently cultivated rapeseed varieties. Specifically, the area and functional duration of representative canopy leaves (first sessile leaf) of rapeseed plants from the initial flowering stage to the pod-forming stage were measured. This involved rapidly measuring the leaf length, width, and area of sessile leaves and accurately identifying their developmental and senescence time points to screen for superior canopy leaf materials.
[0045] After hybridization, backcrossing, and self-pollination with the main cultivated variety, specifically, the selected materials with superior canopy leaves are hybridized with ZS11 to obtain F1. The F1 is then backcrossed with ZS11 to obtain BC1F1. Hybrid materials are selected and backcrossed with ZS11 again, followed by self-pollination to obtain a large number of BC2F2 individual plants. These superior BC2F2 individual plants, selected using relevant techniques, are then used in breeding experiments. This allows for small-scale and efficient improvement of the canopy leaves of the current main rapeseed varieties. This method can evaluate superior rapeseed canopy leaves, screen for excellent canopy germplasm, and provide strong support for rapeseed canopy improvement breeding.
[0046] Results Analysis: The selection of superior canopy leaf area from individual BC2F2 plants was used for genetic regulation analysis or breeding applications. The specific steps in the above-mentioned canopy area selection method, focusing on sessile leaf length, width, and area, were used to screen for superior leaf area from individual BC2F2 plants. Figure 8 Materials such as 604-4, 426-14, 623-4, 620-8, and 620-15 were used. The selected BC2F2 plants with excellent canopy leaf area were further screened for materials with excellent canopy leaf function duration. The development and senescence time points of the first sessile leaf were used to screen for BC2F2 plants with excellent canopy leaf function duration. Finally, the F2 population's sessile leaf superior plants were selected. Figure 9 (As shown): 426-14, 620-8, 620-15.
[0047] The above description is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants, characterized in that, Includes the following steps: A. Determine key trait indicators of canopy leaves from the initial flowering stage to the pod-bearing stage of rapeseed plants grown in the field or greenhouse, including: 1) Canopy leaf area measurement: During the full bloom period, measure the length, width, and leaf area of the first sessile leaf. 2) Statistics on the duration of canopy leaf function: record the development time of the first sessile leaf at the initial flowering stage and the senescence time at the silique stage to obtain the duration of the sessile leaf's function. B. Propose key screening and definition criteria for dominant leaf germplasm in rapeseed canopy leaves, including: 1) To identify the dominant germplasm in terms of canopy leaf area, compare the first sessile leaf of the candidate material with the current main reference variety. The sessile leaf area exceeding 50% is the dominant germplasm in terms of sessile leaf area. 2) Identify the dominant germplasm for canopy leaf function duration. Materials whose sessile leaf function duration exceeds that of the current main reference variety by 20% or whose sessile leaves remain green until two weeks before the rapeseed plant's siliques mature are defined as dominant germplasm for sessile leaf function duration.
2. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The rapeseed mentioned refers to rapeseed crops used for the production of edible oil, including Brassica napus, Chinese cabbage rapeseed, and mustard rapeseed.
3. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The germplasm mentioned includes germplasm resources and breeding population materials of various types of crops.
4. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The canopy leaves refer to the upper leaves of the main stem of rapeseed from the initial flowering stage to the pod-bearing stage, including all sessile leaves and about three short-stalked leaves on the main stem of the rapeseed plant.
5. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The currently main reference varieties include Zhongshuang 11, Zhongyouza 39, Zhongyouza 19, and Huayouza 50.
6. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The method for measuring the canopy leaf area includes: taking photos of representative canopy leaves in vivo or removing them from the plant for photography; and using a leaf analysis system to obtain data on the leaf length, width, and leaf area of different individual plants of the material.
7. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The method for statistical analysis of canopy leaf function duration includes: recording the development time points of representative canopy leaves; observing and recording the leaf color of canopy leaves from normal green to yellow through manual visual observation; further detecting changes in chlorophyll content in the same canopy leaf to determine the senescence of the canopy leaves; recording the senescence time points of the canopy leaves; and statistically analyzing the canopy leaf function duration.
8. The method for screening and identifying dominant germplasm in the canopy leaves of rapeseed plants as described in claim 1, characterized in that, The method for identifying and screening dominant germplasm in the canopy leaves prioritizes the use of the first sessile leaf, and when necessary, combines the use of the short petiole leaf at the top of the main stem and other sessile leaves.
9. The application of a screening and identification method as described in any one of claims 1-8 in rapeseed breeding.
10. The application of a screening and identification method as described in any one of claims 1-8 in the canopy improvement of rapeseed breeding parents, characterized in that, The superior canopy leaf germplasm obtained is introduced into rapeseed breeding materials or parents through 3-5 generations of continuous hybridization to improve the canopy leaves.