Method for maintaining purity of high-oil-content single plant selection of high generation population of brassica napus

Abstract

The application relates to the field of Brassica napus breeding, and discloses a pureness-keeping method for high-oil-content single-plant selection of a high-generation population of Brassica napus, which comprises the following steps: selecting a plurality of high-generation Brassica napus breeding populations; screening single plants of the Brassica napus meeting breeding requirements at a mature stage of the Brassica napus and marking the single plants as primary selected single plants; harvesting the silicles of the primary selected single plants, and reserving the main stems and branch stems; drying and threshing the silicles to obtain grains, using a near-infrared instrument to analyze and detect the grains, screening grains meeting detection requirements and the primary selected single plants corresponding to the grains, and taking the screened primary selected single plants as target single plants; regenerating and cultivating the target single plants; and using a net cover to isolate and forcibly self-pollinate the Brassica napus single plants with high-oil-content potential at a flowering stage.

Description

Technical Field

[0001] This invention relates to the field of rapeseed breeding, specifically to a method for preserving the purity of high-oil-content single plants selected from high-generation populations of rapeseed. Background Technology

[0002] Rapeseed (Brassica napus) is an important oilseed crop, a winter oilseed crop that does not compete with other oilseed crops for land. Rapeseed seeds typically contain 30%–50% oil, indicating significant development potential. Breeding new, high-oil-content, high-quality rapeseed varieties is crucial for achieving high and stable yields. The oil content of rapeseed is mainly influenced by additive effects, which are the cumulative effects of the genotype values ​​of multiple minor genes affecting quantitative traits. Since additive effects can accumulate through generations of selection, and the oil content of rapeseed exhibits maternal inheritance, continuous single-plant selection over multiple generations has a significant effect on increasing the oil content of rapeseed.

[0003] The commonly used method for selecting individual plants is pedigree selection, also known as the pedigree method. This is a selection method frequently used in hybridization breeding. Starting from the first segregating generation of the hybrid, each subsequent generation uses selected individual plants as units for separate planting. After several generations of individual plant selection until the traits of the lines are stable and consistent, the selected lines are then mixed and harvested as a new strain. In the middle generation population, many genetic traits are not completely stable, and the probability of genetic variation is relatively high, which affects the accuracy of selecting individual plants with high oil content.

[0004] Brassica napus is a cross-pollinated crop, making it prone to biological contamination during production and breeding, which affects its quality and yield. In current technology, when using pedigree selection for breeding Brassica napus, single-plant selection to prevent contamination typically involves bagging during flowering to force self-pollination and avoid pollen contamination. However, this method is labor-intensive and inefficient due to the large number of breeding populations, requiring bagging of each plant individually during flowering, and the need to remove and remove bags after pod formation to ensure sufficient space for seed growth. Summary of the Invention

[0005] To address the aforementioned shortcomings or defects in the existing technology, this invention provides a method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus, reducing the number of bags required for each plant, decreasing workload, and improving breeding efficiency.

[0006] To achieve the above objectives, the present invention provides a method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus, comprising the following steps:

[0007] S1: Select several high-generation Brassica napus breeding populations and adopt isolation measures to reduce cross-pollination rate for breeding and planting;

[0008] S2: At the maturity stage of Brassica napus, select single plants of Brassica napus that meet the breeding requirements and mark them as preliminary single plants;

[0009] S3: Select individual plants for initial harvesting to obtain pods, while retaining the main stem and branch stalks;

[0010] S4: The obtained pods are dried, threshed, and seeds are obtained. Near-infrared spectrometer is used to analyze and detect the obtained seeds, and the seeds that meet the detection requirements and the corresponding preliminary single plants are selected. The selected preliminary single plants are used as target single plants.

[0011] S5: Regenerate the target single plant obtained in step S4 to obtain a single plant of Brassica oleracea with high oil content potential.

[0012] S6: The oilseed plants of the Brassica oleracea type with high oil content potential obtained in step S5 are subjected to forced self-pollination by netting isolation during the flowering period;

[0013] S7: Harvest the seeds of the single Brassica napus plant with high oil content potential after pod formation in step S6 to obtain Brassica napus seeds with high oil content potential.

[0014] The present invention provides a method for preserving the purity of high-oil-content single plants in a high-generation population of Brassica napus, which has the following advantages: Initial selection of single plants meeting breeding requirements is performed from the high-generation breeding population. The pods obtained from the initial selection are dried and threshed to obtain seeds. The seeds are then tested, and the initial selection plants whose seeds meet the testing requirements are retained as target plants. These target plants are then bagged and self-pollinated for regeneration cultivation to obtain single plants with high oil content potential. Finally, the single plants produce pods and seeds to obtain rapeseed seeds with high oil content potential, thus achieving the purpose of preserving purity and preventing contamination. In the breeding process, only the target plants need to be bagged, reducing the number of bags required, decreasing workload, and improving breeding efficiency.

[0015] Furthermore, between step S2 and step S3, the following step is also included: applying fertilizer uniformly before harvesting.

[0016] Furthermore, in step S3, the selected individual plants are harvested on the same day to obtain pods.

[0017] Furthermore, between step S3 and step S5, the following step is also included: performing a tilting treatment on the initially selected individual plants to promote growth.

[0018] Furthermore, between step S3 and step S5, the following step is also included: spraying a fungicide on the cut of the initially selected single plant for sterilization treatment.

[0019] Furthermore, between step S3 and step S5, the following step is also included: transplanting the initially selected individual plants.

[0020] Furthermore, in step S4, the requirements for grain testing include erucic acid ≤3%, glucosinolates ≤30μmol / g, and oil content higher than 45.0%.

[0021] Furthermore, the initial selected plants corresponding to the grains that meet the testing requirements are sorted in descending order of oil content, and a suitable number of the top-ranked initial selected plants are selected as target plants.

[0022] Furthermore, in step S6, the obtained high-oil-content Brassica napus plants are artificially pollinated during the flowering period.

[0023] Furthermore, it also includes step S8: using the seeds harvested in step S7 as breeding material for the next generation, and repeating steps S1 to S5 at least repeatedly.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] Figure 1 This is a logic block diagram of a method for preserving the purity of high-oil-content single plants in a high-generation population of Brassica napus according to the present invention.

[0026] Figure 2 This is a logic block diagram showing the step of applying fertilizer between steps S2 and S3;

[0027] Figure 3 This is a logic block diagram of the tilting and growth-promoting treatment steps located between steps S3 and S4;

[0028] Figure 4 This is a logic block diagram of the tilting and growth-promoting treatment steps located between steps S4 and S5.

[0029] Figure 5 This is a logic block diagram showing that the tilting and growth-promoting treatment steps and step S4 are performed simultaneously.

[0030] Figure 6 This is a logic block diagram showing the sterilization process located between steps S3 and S4.

[0031] Figure 7 This is a logic block diagram showing the sterilization process located between steps S4 and S5.

[0032] Figure 8 This is a logic block diagram showing that the sterilization process and step S4 are performed simultaneously.

[0033] Figure 9 This is a logic block diagram showing the transplanting process between steps S3 and S4;

[0034] Figure 10This is a logic block diagram showing the transplanting process between steps S4 and S5.

[0035] Figure 11 This is a logic block diagram showing that the transplanting process and step S4 are performed simultaneously.

[0036] Figure 12 This is a schematic diagram showing the range of the number of initial selected individual plants and the target individual plants. Detailed Implementation

[0037] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0038] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the orientation in the assembled and used state. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.

[0039] Combined with appendix Figure 1 The present invention discloses a method for preserving the purity of high-oil-content single plants in a high-generation population of Brassica napus, comprising the following steps:

[0040] S1: Select several high-generation Brassica napus breeding populations and adopt isolation measures to reduce cross-pollination rate for breeding and planting;

[0041] S2: At the maturity stage of Brassica napus, select single plants of Brassica napus that meet the breeding requirements and mark them as preliminary single plants;

[0042] S3: Select individual plants for initial harvesting to obtain pods, while retaining the main stem and branch stalks;

[0043] S4: The obtained pods are dried, threshed, and seeds are obtained. Near-infrared spectrometer is used to analyze and detect the obtained seeds, and the seeds that meet the detection requirements and the corresponding preliminary single plants are selected. The selected preliminary single plants are used as target single plants.

[0044] S5: Regenerate the target single plant obtained in step S4 to obtain a single plant of Brassica oleracea with high oil content potential.

[0045] S6: The oilseed plants of the Brassica oleracea type with high oil content potential obtained in step S5 are subjected to forced self-pollination by netting isolation during the flowering period;

[0046] S7: Harvest the seeds of the single Brassica napus plant with high oil content potential after pod formation in step S6 to obtain Brassica napus seeds with high oil content potential.

[0047] In higher generations of populations, long-term self-pollination and selection reduce the outcrossing rate to some extent, helping to maintain genetic purity. At the same time, after multiple generations of selection and self-pollination, unfavorable genetic variations are eliminated, making it easier to select individual plants with high oil content genetic potential in higher generations of populations, which is conducive to rapidly increasing oil content.

[0048] Using the above-mentioned purity preservation method, single-plant varieties of Brassica napus that meet the breeding requirements are selected as initial single plants. Only the seeds obtained after drying the harvested pods from these initial single plants are analyzed. Based on the oil content of the seeds, corresponding initial single plants are selected and designated as target single plants. These target single plants are then subjected to regeneration cultivation and forced self-pollination through bagging to obtain single-plant varieties of Brassica napus with high oil content potential. Finally, pods are formed and seeds are harvested, achieving the goal of purity preservation and contamination prevention. Throughout the entire breeding purity preservation process, it is not necessary to bag each single-plant variety of Brassica napus in the breeding population. Only the target single plants with high oil content potential need to undergo bagging isolation and forced self-pollination during the flowering period, reducing the number of bags required, thereby reducing workload and improving breeding efficiency.

[0049] It should be noted that, for the existing pedigree selection method that uses flowering bagging, on the one hand, it requires bagging each individual breeding plant, which is labor-intensive. On the other hand, the large number of bagged breeding plants also has the following disadvantages, affecting breeding efficiency.

[0050] If rapeseed is bagged and then encounters heavy rainfall, the large number of bagged breeding plants means that some plants cannot be bagged in time. This affects the oil content and other quality of the seeds harvested from self-pollination, and may even cause rapeseed to become diseased and unable to be harvested normally. This affects the results of quality testing, leading to omissions and misjudgments in the selection of individual plants, and reducing breeding efficiency.

[0051] After the flowers were bagged, some of the bags were damaged or fell off, causing pollen to cross between individual plants and making it impossible to maintain purity.

[0052] After bagging during the flowering period, the growth space of some rapeseed plants is restricted, which may even affect the growth and development of the main inflorescence of the bagged plant and affect the plant type of the rapeseed plant. As a result, the expected breeding goals cannot be achieved in terms of both plant type and oil content.

[0053] The large number of rapeseed plants requiring bagging makes it difficult to control the timing of bagging, especially during rainy weather when field operations are inconvenient. As a result, some individual plants are bagged too late, missing the peak flowering period or even approaching the end of the flowering period. This reduces the selection of flower buds and inflorescences available for bagging, increasing the difficulty of bagging.

[0054] By adopting the above-mentioned purity preservation method of the present invention, the number of individual plants required for bagging is reduced, the probability of the above-mentioned adverse factors is reduced or even overcome, thereby achieving the goal of improving breeding efficiency.

[0055] The purification method in this invention will be described in detail below.

[0056] In step S1, the selected high-generation breeding populations can be F5 and F6 generation breeding populations. It should be noted that in the breeding process of Brassica napus, the pollen-providing parent is the male parent, and the pollen-receiving parent is the female parent. The parents are the parental generations, and through continuous hybridization, their offspring are the offspring generations; for example, the F5 generation breeding population is the fifth generation of F5. Different breeding experiments and goals require different numbers of generations to achieve the desired genetic stability. Generation division can be based on the actual number of breeding generations; for example, F1 and F2 are low-generation, F3 and F4 are mid-generation, and F5 or later are high-generation. In other embodiments, the specific generation is based on the actual number of breeding generations. In this embodiment, three high-generation breeding populations are selected, with their parents all from the double-low basal line of Brassica napus bred by the Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University. Each population is planted with 500-600 plants. According to GB / T11762-2006, "double low" rapeseed varieties refer to rapeseed varieties with erucic acid content ≤3% and glucosinolate content ≤35μmol / g.

[0057] During planting, certain isolation measures should be taken between different breeding populations and between different individuals within the same breeding population to reduce the cross-crossing rate between populations and individuals. This helps to reduce hybridization interference, avoid unpredictable trait combinations caused by large differences in genetic background, facilitate the rapid identification of individuals that do not meet the breeding requirements, and thus improve the efficiency of screening target plants.

[0058] Specifically, isolation measures include spatial isolation, physical isolation, natural barrier isolation, wind direction control, planting layout, planting density, and flowering period management.

[0059] Spatial isolation: No other rapeseed varieties or cruciferous plants should be planted within a 200-meter radius of the rapeseed planting area. Sufficient distance should be maintained between breeding populations to increase pollen dispersal distance and reduce the chance of pollen transfer between populations.

[0060] Physical isolation: Establish physical barriers, such as high-density isolation nets, around rapeseed planting areas to block pollen carried by the wind.

[0061] Natural barrier isolation: Utilize natural barriers such as mountains and forests. The height and width of the natural barriers must be appropriate to ensure the isolation effect.

[0062] Wind direction control: Using wind direction to control the direction of pollen dispersal, such as planting other crops or building barriers in the upwind area of ​​rapeseed-growing regions.

[0063] Planting layout: Within the rapeseed planting area, a strip planting layout can be adopted to reduce pollen spread between individuals within the same population.

[0064] Planting density: Control the planting density to avoid pollen dispersal distance being too short due to excessive planting density within the breeding population.

[0065] Flowering period management: Based on the growth cycle and flowering time of Brassica napus, the planting time should be arranged reasonably to reduce cross-pollination and achieve time isolation.

[0066] Furthermore, adjacent planting populations share similar genetic backgrounds, which can reduce the occurrence of unpredictable trait combinations caused by large differences in genetic background. Whether the genetic background is similar can be determined by comprehensively understanding parental information, comparing the agronomic traits of the offspring of the parents, and using molecular marker data.

[0067] In this embodiment, a high-generation breeding population with similar genetic backgrounds is used. The agronomic traits or genetic backgrounds compared include, but are not limited to, stem height, stem diameter, flowering time, disease resistance, and fruit yield and quality (such as the number of siliques, seed size, and seed coat color). Offspring of the same parents usually exhibit similar agronomic traits and genetic backgrounds. Specific evaluation methods include, but are not limited to: stem height and stem diameter measurements within ±10% of the average value indicating a similar genetic background; flowering time differences of no more than 2 days indicating a similar genetic background; individuals in the breeding population having similar resistance levels to specific diseases indicating a similar genetic background; and similar yield and quality traits (such as the number of siliques, seed size, and seed coat color) indicating a similar genetic background.

[0068] Molecular markers are heritable and detectable DNA sequences or proteins, and specific DNA segments that reflect certain differences in the genome of an individual or population. The consistency of molecular marker data is used to determine whether individuals share a similar genetic background.

[0069] In step S2, the formulation of breeding requirements and quantitative standards need to be adjusted according to the breeding objectives and the local planting environment. If necessary, the planting and breeding experience of personnel should be considered. Specifically, individual plants with compact plant type, suitable plant height, good disease resistance or high yield can be selected as initial single plants and marked with tags or ropes.

[0070] In this embodiment, high-yielding oilseed rape plants with good yields were selected from three high-generation breeding populations in the first year and marked with red string. Different marking methods could be used for the initial selected plants in the three different populations to distinguish them.

[0071] In step S3, after harvesting the siliques from the initially selected individual plants, the main stem and branches are retained for subsequent regeneration cultivation. Harvesting is generally carried out when the siliques are yellowish-green, the pods are a yellowish-brown color, and the stems are still green and not dry. Other plants not selected in the initial phase can be harvested using conventional methods.

[0072] In addition, the initial selected plants in the same breeding population are harvested on the same day to obtain pods. Since the oil content of rapeseed pods is affected by the harvest time, harvesting on the same day makes it easier for the maturity of the plant samples to be consistent in subsequent determination of pod quality and oil content, ensuring the reliability of oil content determination, thereby ensuring the selection of breeding plants with high oil content potential.

[0073] In step S4, the requirements for detecting rapeseed kernels include erucic acid ≤3%, glucosinolates ≤30 μmol / g, and oil content higher than 45.0%. That is, non-low-erucic acid and low-glucosinolate content rapeseed kernels and their corresponding initial selected plants are screened out to obtain initial selected plants with high oil content potential. Furthermore, based on the oil content of the kernels, the obtained initial selected plants are sorted in descending order, and a suitable number of the top-ranked initial selected plants are selected as target plants for step S5.

[0074] In this embodiment, the target plants are sorted in descending order of seed oil content, and the top five target plants are selected for step S5. These five selected target plants are those with high oil content potential. It should be noted that: a target plant with high oil content potential means that the probability of its pods having an oil content higher than 45.0% in mixed cultivation is high, not that all siliques have an oil content higher than 45.0%. Step S3 involves selecting siliques from the same location, such as siliques from the main stem or siliques from the main stem and first branches. In other embodiments, the number of target plants in step S5 can be adjusted according to actual breeding needs, generally selecting plants with the top 10% oil content, and no fewer than three. Specifically, in this embodiment, the breeding population is three, and a total of fifteen high-oil-content target plants are obtained.

[0075] In step S5, the target plants with high oil content potential selected in step S4 are regenerated. During the regeneration process, soil moisture should be monitored, keeping the soil slightly moist but avoiding excessive dryness or wetness; generally, the soil moisture should be maintained at 60%–70%. During rapeseed regeneration, boron fertilizer can be sprayed at the budding or early flowering stage, depending on the actual situation, and certain temperature control and pest and disease control measures should be taken. In addition, the target plants to be regenerated are generally treated to induce growth. Specifically, the following two implementation methods can be used:

[0076] I. Between steps S2 and S3, in conjunction with the appendix Figure 2As shown, fertilizer is applied uniformly before harvesting to promote the regeneration of rapeseed plants after harvest. Specifically, fertilizer is applied uniformly 10 to 15 days before harvesting. Compound fertilizer and urea can be evenly spread using drones to reduce mechanical damage to rapeseed plants caused by manual fertilization. In this embodiment, fertilizer is applied to all plants, regardless of whether they were initially selected, reducing the difficulty of the fertilization process. Of course, fertilizer can also be applied only to the initially selected plants to reduce the amount of fertilizer used.

[0077] II. Between step S3 and step S5, in conjunction with the appendix Figure 3 To be continued Figure 5 As shown, this involves applying a tilting treatment to the initially selected individual plants after harvesting and before planting to promote growth. Specifically, the tilting method involves using tools such as wooden sticks or bamboo poles to press down on the base of the plant, causing it to lean but not fall over. The angle of the tilt should be moderate to ensure that the plant can grow stably.

[0078] It should be noted that the two methods of catalytic and growth-promoting treatments described above have different operating times, therefore they do not interfere with each other. Both methods are implemented in this embodiment.

[0079] Furthermore, the near-infrared spectroscopy analysis in step S4 is an indoor operation, while the growth-inducing and growth-promoting treatment steps are field operations. The second method of growth-inducing and growth-promoting treatment (i.e., tilting growth-promoting treatment) is performed between steps S3 and S5. Therefore, the tilting growth-promoting treatment and step S4 can be performed simultaneously or sequentially. Different processing times for the tilting growth-promoting treatment and step S4 will also produce different effects.

[0080] Specifically, if the slant-inducing treatment is performed before or simultaneously with step S4, and no target plants with high oil content potential are screened out, then all the initially selected plants in step S3 need to undergo the slant-inducing treatment.

[0081] When the slant-inducing treatment is performed after step S4, target plants with high oil content potential have been screened out. At this point, only the screened target plants with high oil content potential need to be subjected to the slant-inducing treatment.

[0082] In comparison, the tilting-induction treatment, performed before or simultaneously with step S4, involves a larger workload, but its earlier timing results in a more significant growth-promoting effect. Conversely, the tilting-induction treatment, performed after step S4, also involves a larger workload, but its growth-promoting effect is less pronounced.

[0083] In this embodiment, two methods are used to promote growth and induce growth, which ensures the effectiveness of these two methods. Furthermore, the tilting and promoting growth process is performed after step S4, which reduces the workload of tilting and promoting growth.

[0084] In a further configuration, between step S3 and step S5, a step of spraying a fungicide on the cut of the initially selected marble for sterilization and a step of transplanting the initially selected individual plants may be included.

[0085] For the sterilization process, combined with the attached Figure 6 To be continued Figure 8 As shown, after harvesting the initially selected individual plants in step S3, fungicides such as carbendazim are sprayed promptly to prevent infection of the cut surfaces and reduce the occurrence of diseases later. The fungicide treatment step can be performed simultaneously with or sequentially with step S4. When the fungicide treatment step is performed before or simultaneously with step S4, all initially selected individual plants harvested in step S3 need to be fungicide treated. This involves a larger workload, but the earlier timing results in better fungicide effects. When the fungicide treatment step is performed after step S4, only the target individual plants with high oil content potential selected in step S4 need to be fungicide treated. This involves a smaller workload, but the later timing results in poorer fungicide effects.

[0086] Generally, after the pods are dried, it takes about a week to thresh them and obtain the seeds. That is, there is usually a one-week interval between the seed detection time in step S4 and the implementation time in step S3. Therefore, in this embodiment, the sterilization effect is given priority, and sterilization is carried out immediately after harvesting the initially selected individual plants in step S3 to minimize the risk of infection at the cut and disease.

[0087] For the transplanting process, please refer to the attached instructions. Figure 9 To be continued Figure 11 As shown, in actual single-plant cultivation, the choice between leaving the target plant in the field or transplanting it will be considered. It is important to note that after transplanting, three breeding populations should still be maintained for subsequent transplanting. When transplanting a target plant, the transplanting pots should be well-ventilated and well-drained containers, such as ceramic or plastic pots, ensuring the container size is suitable for the root development of the oilseed plant. Use fertile, well-drained soil, such as a mixture of peat moss, perlite, and organic fertilizer. Transplanting should be avoided in high-temperature environments and is generally carried out in the morning when the temperature is suitable and there is sufficient sunlight to improve the survival rate.

[0088] In this embodiment, the transplanting step is performed after step S4. If transplanting is required, only the target plants with high oil content potential need to be transplanted, resulting in minimal transplanting workload. Of course, since the grain detection step in step S4 takes place approximately one week after step S3, if there is a need to transplant the initially selected plants before step S4, the transplanting step can also be performed before or simultaneously with step S4.

[0089] It should be noted that, in conjunction with the appendix Figure 12As shown, the target plant obtained in step S4 is one or more of the initially selected plants in step S2, meaning the number of initially selected plants is not less than the number of target plants. Generally, the number of initially selected plants is greater than the number of target plants. Therefore, disinfecting the cuts, pressing to promote growth, or transplanting all initially selected plants can fully ensure that all target plants undergo the same treatment.

[0090] In step S6, before the rapeseed flowers bloom, the flower buds and inflorescences are completely covered with a net, and the integrity of the net is checked regularly to prevent pollen or insects from entering. In addition to forced self-pollination through isolation during flowering, the obtained high-oil-content Brassica napus plants can be artificially pollinated during the flowering period to compensate for the inadequacy of natural pollination and improve the seed setting rate of rapeseed.

[0091] In step S7, the high-oil-content cabbage oilseed plants from step S6 are harvested after pod formation, thereby obtaining seeds with high oil content potential.

[0092] Seeds of Brassica oleracea var. truncatum with high oil content potential, obtained through the above-described purification method, can also be used as breeding material for the next generation population. The previous purification steps can be repeated to improve the purity level and ensure the stable inheritance of individual plant traits. Specifically, after step S7, step S8 is included: using the seeds harvested in step S7 as breeding material for the next generation population, and repeating steps S1 to S5 at least once.

[0093] In this embodiment, the seeds harvested in step S7 are planted in the second year, and are similarly divided into several breeding populations. Steps S1 to S7 are repeated, and the seeds are harvested again in the second year. Specifically, five target plants are selected in step S4, and the seeds of these five target plants are harvested in step S7. In the second year, the seeds of one or two of these target plants are selected for planting.

[0094] The seeds harvested in the second year were then replanted, and steps S1 to S5 were repeated to obtain three groups of high-oil-content Brassica napus in the third year. Ultimately, in the three groups of Brassica napus breeding populations obtained in the third year, the highest oil content per plant was 49.1%, 51.7%, and 52.1%, respectively. Compared to the common oil content of 30%–50% per plant in Brassica napus, the oil content of the Brassica napus bred using this method is at a medium-high level, even exceeding the common oil content range, indicating a significant increase in oil content after breeding using this method.

[0095] This application provides a high-oil-content Brassica napus cultivated using the above method, which is registered in the "Variety Registration Inquiry - China Seed Industry Big Data Platform" under the variety name "Zhejiang University 635".

[0096] The URL for "Variety Registration Inquiry - China Seed Industry Big Data Platform" is: http: / / 202.127.42.47:6010 / index.aspx.

[0097] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0098] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0099] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preserving the purity of high-oil-content single plants in a high-generation population of Brassica napus, characterized in that, Includes the following steps: S1: Select several high-generation Brassica napus breeding populations and adopt isolation measures to reduce cross-pollination rate for breeding and planting; S2: At the maturity stage of Brassica napus, select single plants of Brassica napus that meet the breeding requirements and mark them as preliminary single plants; S3: Select individual plants for initial harvesting to obtain pods, while retaining the main stem and branch stalks; S4: The obtained pods are dried, threshed, and seeds are obtained. Near-infrared spectrometer is used to analyze and detect the obtained seeds, and the seeds that meet the detection requirements and the corresponding preliminary single plants are selected. The selected preliminary single plants are used as target single plants. S5: Regenerate the target single plant obtained in step S4 to obtain a single plant of Brassica oleracea with high oil content potential. S6: The oilseed plants of the Brassica oleracea type with high oil content potential obtained in step S5 are subjected to forced self-pollination by netting isolation during the flowering period; S7: Harvest the seeds of the single Brassica napus plant with high oil content potential after pod formation in step S6 to obtain Brassica napus seeds with high oil content potential. Between step S3 and step S5, the following step is also included: the selected individual plants are subjected to a tilting treatment to promote growth.

2. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, Between step S2 and step S3, the following step is also included: applying fertilizer uniformly before harvesting.

3. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, In step S3, the initial selected individual plants are harvested on the same day to obtain pods.

4. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, Between step S3 and step S5, the following step is also included: spraying a fungicide on the cut of the initially selected single plant for sterilization treatment.

5. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, In step S4, the requirements for grain testing include erucic acid ≤3%, glucosinolates ≤30μmol / g, and oil content higher than 45.0%.

6. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 5, characterized in that, The initial selected plants corresponding to the seeds that meet the testing requirements are sorted in descending order of oil content, and a suitable number of the top-ranked initial selected plants are selected as target plants.

7. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, In step S6, the obtained high-oil-content cabbage oilseed plants are artificially pollinated during the flowering period.

8. The method for preserving the purity of high-oil-content single plants in high-generation populations of Brassica napus according to claim 1, characterized in that, It also includes step S8: using the seeds harvested in step S7 as breeding material for the next generation, and repeating steps S1 to S5 at least.

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