Method for shortening soybean breeding cycle based on plant after-ripening

Abstract

The invention discloses a method for shortening a soybean breeding cycle based on plant after-ripening, which is suitable for a soybean autumn sowing area, and comprises the following steps: after a soybean plant enters a R6 period and before the soybean plant enters a R8 period, harvesting an overground plant of the whole plant; the harvested plants are placed in a ventilated and dry indoor environment to be subjected to after-ripening treatment; the after-ripening treatment time is 0-8 days; peeling pods and taking seeds after the after-ripening treatment, and sowing or storing. Compared with the prior art, the method has the advantages that soybean plants are harvested from R6 to R7 and subjected to after-ripening treatment for 0-8 days, the seed bud rate is remarkably increased, the problem of seed mildewing caused by high temperature and high humidity in traditional spring sowing is solved, the soybean growth cycle is shortened, and the yield of the soybeans is increased. Local two-generation breeding in one year and remote (local + Hainan) three-generation breeding in one year can be achieved, breeding efficiency is improved, and the long-standing problem that the spring sowing and seed reserving effect is poor is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of crop breeding, specifically a fresh soybean breeding and cultivation technology, which aims to effectively shorten the growth cycle of fresh spring soybeans through plant after-ripening treatment, significantly improve the seed germination rate, and thus greatly accelerate the breeding process. Background Art

[0002] Fresh soybeans (commonly known as "edamame" or "vegetable soybeans") are a popular crop with a unique flavor, rich nutritional value, and widespread market demand. Rich in nutrients such as protein, fat, starch, vitamins, plant fiber, and unsaturated fatty acids, fresh soybeans can be processed into a variety of foods, including soy milk, fresh soy milk, and ice cream. Fresh soybeans also have health benefits, demonstrating significant effectiveness in preventing and assisting in the treatment of various chronic diseases.

[0003] However, the breeding cycle of fresh soybeans is long and is restricted by climatic conditions, resulting in low seed germination rate and low breeding efficiency, which seriously affects the promotion speed of new varieties and the development of the fresh soybean industry.

[0004] In the process of realizing the present invention, the inventors discovered that the prior art has at least one of the following technical problems: a) Seeds mature late and have low germination rates Spring-sown fresh soybeans in the Yangtze River Basin typically reach full maturity (R8) between late July and early August. Due to the high temperatures and humidity of summer during this period, seeds are prone to wrinkling, cracking, and mildew, resulting in extremely low germination rates. This problem not only affects breeding efficiency but also makes it difficult for growers to obtain high-quality seeds.

[0005] b) Conventional spring sowing will miss the best time for autumn sowing The maturity period (R8) of spring-sown fresh soybeans is usually from the end of July to early August, which means that the best sowing period for autumn sowing (mid-to-late July) has been missed when the seeds are harvested, resulting in difficulties in breeding generations and further reducing breeding efficiency.

[0006] c) Long breeding cycle Existing fresh soybean breeding methods typically require one generation per year, resulting in a long breeding cycle. Even with the southern breeding method (transplanting to Hainan during winter for additional generations), only two generations can be achieved per year, making it difficult to meet the demand for rapid breeding.

[0007] d) Spring sowing seed retention effect is poor The problem of poor seed quality of spring planting is a technical problem that has been realized by Mei Jianmei et al. in 2004 but has not been properly solved so far. The seed of fresh soybean is matured in a high-temperature and humid environment, and the seed vigor decreases significantly during storage until the next year, resulting in low seedling emergence rate and poor growth potential after sowing, which seriously affects the yield and quality of fresh soybean. In order to solve this problem, Mei Jianmei et al. proposed the autumn planting technology, and the results showed that the germination rate and growth potential of autumn planting seeds were significantly better than those of spring planting seeds, thereby verifying the severity of the problem of spring planting seed. Since the climate conditions in the Yangtze River Basin and other major planting areas have not changed fundamentally for a long time, the high-temperature and humid environment continues to exist, and the problem of poor seed quality of spring planting has not been effectively solved, which has become an important bottleneck restricting the development of fresh soybean industry.

[0008] e) Defects of other prior art The immature embryo culture method: Although the method of drying and transferring the immature embryo to the culture medium for germination can shorten the breeding cycle to some extent, the operation is complicated, the cost is high, and the seed germination rate is low, which is difficult to be applied on a large scale.

[0009] The fresh grain direct sowing method: Although the method of directly peeling and sowing the immature fresh grains can realize 90-day generation, it is easy to damage the seed coat and embryo, resulting in low seedling emergence rate, many weak seedlings and poor seed quality. SUMMARY

[0010] Therefore, the present application aims to provide a method for improving the seed germination rate and shortening the breeding cycle of soybean by plant after-ripening, thereby realizing efficient breeding.

[0011] The present application provides a method for shortening the breeding cycle of soybean based on plant after-ripening, which is suitable for soybean autumn planting areas, and includes the following steps: a) After the soybean plant enters the R6 stage and before it enters the R8 stage, the whole plant is harvested; b) The harvested plant is placed in a well-ventilated and dry indoor environment for after-ripening treatment; c) The after-ripening treatment time is 0 to 8 days; d) After the after-ripening treatment, the seeds are peeled and sowed or stored.

[0012] Compared with the prior art, the present application has the following advantages: The present invention significantly improves the seed germination rate by harvesting soybean plants during the R6 to R7 period and conducting a post-ripening treatment for 0 to 8 days, avoiding problems such as wrinkled or mildewed seeds caused by high temperature and high humidity in traditional spring sowing, while shortening the soybean growth cycle. It can achieve local "two generations breeding in one year" and remote (local + Hainan) "three generations breeding in one year", thereby improving breeding efficiency and solving the long-standing problem of poor seed retention effect of spring sowing.

[0013] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore: in step a), the soybean plants are spring-sown soybean plants.

[0014] Compared with the prior art, the beneficial effects of adopting the above further technical solution are: After the soybean plants in step a) are identified as spring-sown soybean plants, the present invention can significantly improve the quality of spring-sown soybean seeds. Spring-sown soybeans are susceptible to high temperatures and high humidity, resulting in low seed vigor, wrinkling, cracking, or mildew, leading to low germination rates and long breeding cycles. The after-ripening treatment of the present invention can effectively address these issues, increasing the seed germination rate to over 88.3%, shortening the growth period by 4-25 days, reducing reliance on southern propagation and generation, lowering breeding costs, improving breeding efficiency, and increasing the supply of fresh soybean seed sources, thus possessing significant economic value and application prospects.

[0015] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore: the spring sowing time is March to April.

[0016] Compared with the prior art, the beneficial effects of adopting the above further technical solution are: Limiting the spring sowing time to March and April can accurately match the soybean growth cycle and climatic conditions, provide the best time for subsequent ripening treatment and autumn sowing, and significantly improve seed germination rate and breeding efficiency.

[0017] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore: in the step a), the soybeans are fresh soybeans.

[0018] Compared with the prior art, the beneficial effects of adopting the above further technical solution are: By limiting soybeans to fresh-edible soybeans, the present invention more accurately solves the problems of long breeding cycle and low seed germination rate of fresh-edible soybeans based on the characteristics and market demand of fresh-edible soybeans, improves breeding efficiency and seed quality, and meets the urgent needs of the fresh-edible soybean industry to shorten the breeding cycle and improve seed quality.

[0019] On the basis of the above technical solution, the present invention can also be improved as follows: Further, the fresh soybean varieties include Jia Da 133, Zhe Nong 8, Chuan Xian Dou 1, Chuan Dou 155, Gong Xian Dou 4, Gong Xian Dou 5 or Nan Xian Dou 1.

[0020] Compared with the prior art, the beneficial effects of the above further technical solutions are: These fresh soybean varieties have significantly improved seed germination rate and greatly shortened growth period after plant after-ripening treatment in R6 to R7 period. Using these varieties can effectively solve the problems of low seed vigor and long breeding cycle of traditional spring sowing soybean, provide high-quality seeds for autumn sowing, improve breeding efficiency, and meet market demand.

[0021] Based on the above technical solutions, the present application can also be improved as follows: Further, in step a), when the harvest period is R6, the after-ripening treatment time is 4-8 days.

[0022] Compared with the prior art, the beneficial effects of the above further technical solutions are: Limiting the after-ripening treatment time to 4-8 days when the harvest period in step a) is R6 can significantly improve the seed germination rate of fresh soybean. This improvement is based on a large amount of experimental data, such as Jia Da 133 after-ripening for 6 days with a germination rate of 88.3%, and 8 days with a germination rate of 93.3%; Chuan Dou 155 after-ripening for 4 days with a germination rate of 100%. This shows that after-ripening for 4-8 days can significantly improve the seed germination rate, effectively solve the problems of low seed germination rate, easy wrinkling and moldy of R8 period seeds, and easy damage to seed coat of fresh grain direct sowing method, provide high-quality seeds for autumn sowing, and improve breeding efficiency.

[0023] Based on the above technical solutions, the present application can also be improved as follows: Further, in step a), when the harvest period is R7, the after-ripening treatment time is 1-8 days.

[0024] Compared with the prior art, the beneficial effects of the above further technical solutions are: Limiting the after-ripening treatment time to 0-8 days when the harvest period is R7 can significantly improve the seed germination rate and shorten the growth period by 4-19 days, effectively solve the problems of low seed germination rate and long growth period of traditional R8 period harvested seeds, improve breeding efficiency, and meet the demand for autumn sowing and breeding of fresh soybean.

[0025] Based on the above technical solutions, the present application can also be improved as follows: Further, in step c), the number of days of after-ripening is determined by seed germination experiment, and the seed germination rate is not less than 85%.

[0026] Compared with the prior art, the beneficial effects of the above further technical solutions are: By determining the number of days for ripening through seed germination experiments and ensuring that the germination rate is not less than 85%, the optimal ripening time can be accurately locked to avoid low germination rate or unstable seed quality due to improper number of days for ripening, thereby significantly improving seed germination rate and breeding efficiency and meeting the demand for high-quality seeds.

[0027] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, in step d), the sowing is done in autumn, in mid to late July, so as to achieve two generations of breeding per year locally.

[0028] Compared with the prior art, the beneficial effects of adopting the above further technical solution are: By specifying the sowing time in step d) as autumn sowing, which takes place in mid-to-late July, we can fully utilize autumn weather conditions and achieve two generations of breeding per year in this region. This improvement effectively addresses the problem of traditional breeding methods, which only allow one generation of breeding per year. It significantly shortens the breeding cycle, improves breeding efficiency, and ensures seed germination rate and quality, providing strong support for the efficient breeding and promotion of fresh soybeans.

[0029] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore: After harvesting in autumn, the seeds are moved to the tropics in the winter of the same year for reproduction and generation, achieving three generations of reproduction in one year.

[0030] Compared with the prior art, the beneficial effects of adopting the above further technical solution are: By moving the seeds to the tropics for reproduction and generation after autumn sowing and harvesting, we can fully utilize the climatic advantages of tropical regions, achieve three generations of breeding a year, significantly shorten the breeding cycle, improve breeding efficiency, accelerate the selection and promotion of excellent varieties, and effectively solve the problems of long breeding cycle and low efficiency in existing technologies, providing strong support for the development of the fresh soybean industry. DETAILED DESCRIPTION

[0031] The following describes the details in conjunction with specific embodiments.

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0033] In the present application, all the equipment and raw materials can be purchased from the market or commonly used in the industry, unless otherwise specified. The methods in the following examples are conventional methods in the art, unless otherwise specified.

[0034] The term "soybean fall planting area" refers to a geographical area suitable for planting soybeans in the fall. These areas usually have suitable climate conditions, such as moderate temperature and moderate precipitation in the fall, which are suitable for the growth and development of soybeans. The climate characteristics of these places make it possible for soybeans planted in the fall to avoid the high temperature and high incidence of pests and diseases in the summer, while taking advantage of the suitable climate and soil conditions in the fall to achieve better growth and yield performance.

[0035] "Soybean growth period" refers to a series of growth and development stages that soybeans go through from planting to maturity, usually divided into vegetative growth stages (V period) and reproductive growth stages (R period) according to the morphological and physiological characteristics of soybeans.

[0036] Each period is further divided into several periods, and the vegetative period is divided into periods according to the number of nodes on the main stem, and the vegetative period and the reproductive growth period are divided by flowering. The reproductive growth period includes 8 time nodes (R1 to R8). The first flowering period (R1): the day when a flower opens on any node of the main stem. The full flowering period (R2): the day when a flower opens on any node of the uppermost 2 nodes of the main stem with fully expanded leaves. The first pod period (R3): the day when a pod with a length of 5 mm appears on any node of the uppermost 4 nodes of the main stem with fully expanded leaves. The full pod period (R4): the day when a pod with a length of 2 cm appears on any node of the uppermost 4 nodes of the main stem with fully expanded leaves. The initial grain period (R5): the day when the length of the seed in the pod reaches 3 mm on any node of the uppermost 4 nodes of the main stem with fully expanded leaves. The full grain period (R6): the day when the green seeds in the pod fill the seed cavity of the pod on any node of the uppermost 4 nodes of the main stem with fully expanded leaves. The physiological maturity period (R7): the day when a pod on the main stem reaches the normal color. The full maturity period (R8): the day when 95% of the pods reach the normal maturity color.

[0037] All the examples in this embodiment are field planting. The field planting parameters in the examples are: flat planting, row spacing 40 cm, row length 4 m, hole spacing 16 cm, 2 plants per hole, 12 rows per variety (line). The fresh soybean cultivation in the examples is carried out according to the Sichuan Province Fresh Spring Soybean Variety Independent Test Implementation Scheme for routine management. The following 7 materials are set up respectively: Jiaoda 133 is a new variety of national spring soybean for table use. The relevant information of Jiaoda 133: scientific name Glycine max (L.) Merr.; approval number: Guoshen 2011018; breeding unit: Shanghai Jiaotong University.

[0038] Zhenong 8 is a new spring soybean variety for vegetable use in Zhejiang Province. Information about Zhenong 8 includes: scientific name: Glycine max (L.) Merr.; approval number: Zheshendou 2009002; and breeding unit: Vegetable Research Institute, Zhejiang Academy of Agricultural Sciences.

[0039] Chuanxiandou No. 1 is a new spring soybean variety for vegetable production in Sichuan Province. Information about Chuanxiandou No. 1 includes its scientific name, Glycinemax (L.) Merr.; approval number: Chuanshengdou20203003; and was bred by the Institute of Economic Crop Breeding and Cultivation of the Sichuan Academy of Agricultural Sciences, the Weikui Soybean Research Institute of Tieling City, and the Yunong Seed Co., Ltd. in Kaiyuan City.

[0040] Chuandou 155 is a new spring soybean variety for both vegetable and grain use in Sichuan Province. Information about Chuandou 155: Scientific name: Glycinemax (L.) Merr.; Vegetable type approval number: Chuan Shendou 20213004; Grain type approval number: Chuan Shendou 20220003; Breeding institutions: Institute of Economic Crop Breeding and Cultivation, Sichuan Academy of Agricultural Sciences, Weikui Soybean Research Institute, Tieling City, and Kaiyuan Yunong Seed Co., Ltd.

[0041] Gongxiandou No. 4 is a new spring soybean variety for vegetable production in Sichuan Province. Information about Gongxiandou No. 4 includes its scientific name, Glycinemax (L.) Merr.; its approval number is Chuan Shendou 20223004; and it was bred by the Zigong Academy of Agricultural Sciences.

[0042] Gongxiandou No. 5 is a new edible spring soybean variety from Sichuan Province. Information about Gongxiandou No. 5: Scientific name: Glycinemax (L.) Merr.; Approval Number: Chuan Shendou 20243003; Breeding Institutions: Zigong Academy of Agricultural Sciences and Nanjing Agricultural University.

[0043] Related information about Nanxiandou No. 1: Its scientific name is Glycine max (L.) Merr. It is a vegable spring soybean variety bred by the Nanchong Academy of Agricultural Sciences, with Nanchong City, Sichuan Province as the breeding target area.

[0044] 1. Test methods 1. Field design The experiment was conducted at the experimental base of Nanchong Academy of Agricultural Sciences in Luxi Town, Shunqing District, Nanchong City.

[0045] The plot area is 19.2 square meters, with 12 rows in each plot, row spacing of 0.4m, row length of 4m, hole spacing of 0.16m, 2 plants left in each hole, and a density of 20,800 plants per mu.

[0046] The aboveground plants of the eight tested materials were harvested at the R6, R7 and R8 stages.

[0047] The harvest period is set as factor A, the harvest during R6 is A1, the harvest during R7 is A2, and the harvest during R8 is A3.

[0048] The number of days after harvest is set as factor B, where sowing on the day of harvest is set as B1, sowing 2 days after ripening is set as B2, sowing 4 days after ripening is set as B3, sowing 6 days after ripening is set as B4, and sowing 8 days after ripening is set as B5.

[0049] There were 11 treatments in the experiment, namely: (1) A1B1, (2) A1B2, (3) A1B3, (4) A1B4, (5) A1B5, (6) A2B1, (7) A2B2, (8) A2B3, (9) A2B4, (10) A2B5, and (11) A3B1.

[0050] 2. Treatment On April 11, 2025, Jiaoda 133, Zhejiang Agricultural No. 8, Sichuan Fresh Bean No. 1, Sichuan Bean No. 155, Gongxian Bean No. 4, Gongxian Bean No. 5, and Nanxian Bean No. 1 were sown at the same time. After emergence, routine management and field observation records were carried out in accordance with the Sichuan Province Fresh Spring Soybean Variety Independent Test Implementation Plan. When the plants of each test material reached the R6 and R7 period, 3 rows of above-ground plants were harvested and placed in a well-ventilated and dry place indoors to dry evenly. After ripening for 0 days, 2 days, 4 days, 6 days, After 8 days of treatment, the pods were peeled and germination tests were carried out, which belonged to treatments (1) A1B1, (2) A1B2, (3) A1B3, (4) A1B4, (5) A1B5, (6) A2B1, (7) A2B2, (8) A2B3, (9) A2B4, and (10) A2B5. When the plants of each test material reached the R8 stage, one row of aboveground plants was harvested and threshed on the same day for germination tests, which belonged to treatment (11) A3B1. When peeling the pods, pods with full bulges in the middle and lower parts, intact grains, and a high degree of maturity were preferred.

[0051] The growth period of each test material is shown in Table 1: Table 1. Sowing period and growth period of experimental materials and record of 100-grain weight at R6 stage Germination test Sowing conditions: Fill 25cm diameter, 18cm high gallon pots (including trays) with nutrient soil and water thoroughly for 1 hour. Sow 120 seeds per treatment, 40 seeds per pot. Cover with approximately 3cm of nutrient soil after sowing. Place the pots indoors. Due to the high temperatures during the experiment, water the trays once daily to keep the soil moist while waiting for seedlings to emerge.

[0052] Sowing time: The harvest date of Jiaoda 133 in the R6 period was July 2, and germination tests were conducted on July 2, July 4, July 6, July 8, and July 10, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R7 period was July 14, and germination tests were conducted on July 14, July 16, July 18, July 20, and July 22, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R8 period was July 24, and sowing was carried out on the same day after harvest.

[0053] The harvest date of Zhejiang Agricultural No. 8 in the R6 period was July 2, and germination tests were conducted on July 2, July 4, July 6, July 8, and July 10, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R7 period was July 14, and germination tests were conducted on July 14, July 16, July 18, July 20, and July 22, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R8 period was July 24, and sowing was carried out on the same day after harvest.

[0054] The harvest date of Sichuan Fresh Bean No. 1 in the R6 period was July 4, and germination tests were conducted on July 4, July 6, July 8, July 10, and July 12, respectively, after 0, 2, 4, 6, and 8 days of ripening; the harvest date in the R7 period was July 14, and germination tests were conducted on July 14, July 16, July 18, July 20, and July 22, respectively, after 0, 2, 4, 6, and 8 days of ripening; the harvest date in the R8 period was July 24, and sowing was carried out on the same day after harvest.

[0055] The harvest date of Sichuan Bean 155 in the R6 period was July 4, and germination tests were conducted on July 4, July 6, July 8, July 10, and July 12, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R7 period was July 14, and germination tests were conducted on July 14, July 16, July 18, July 20, and July 22, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R8 period was July 18, and sowing was carried out on the same day after harvest.

[0056] The harvest date of Gongxiandou No. 4 in the R6 period was July 8, and germination tests were conducted on July 8, July 10, July 12, July 14, and July 16, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R7 period was July 24, and germination tests were conducted on July 24, July 26, July 28, July 30, and August 1, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R8 period was August 2, and sowing was carried out on the same day after harvest.

[0057] The harvest date of Gongxiandou No. 5 in the R6 period was July 8, and germination tests were conducted on July 8, July 10, July 12, July 14, and July 16 after 0, 2, 4, 6, and 8 days of ripening, respectively; the harvest date in the R7 period was July 18, and germination tests were conducted on July 18, July 20, July 22, July 24, and July 26 after 0, 2, 4, 6, and 8 days of ripening, respectively; the harvest date in the R8 period was August 6, and sowing was carried out on the same day after harvest.

[0058] The harvest date of Nanxiandou No. 1 in the R6 period was July 4, and germination tests were conducted on July 4, July 6, July 8, July 10, and July 12, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R7 period was July 18, and germination tests were conducted on July 18, July 20, July 22, July 24, and July 26, respectively, 0, 2, 4, 6, and 8 days after ripening; the harvest date in the R8 period was August 2, and sowing was carried out on the same day after harvest.

[0059] Survey standard: Record the number of seedlings that emerge for each variety 10 days after sowing.

[0060] 2. Results and Analysis As shown in Table 2, the germination rate of Jiaoda 133 seeds at R6 stage increased with the increase of ripening days. The germination rate was the lowest when sown on the 0th day after ripening, that is, on the day of harvest, which was only 15.8%±1.4%. The germination rate was lower than 60.0% when sown on the 4th day after ripening, which was 57.5%±2.5%. The germination rate increased significantly when sown on the 6th day after ripening, which was 88.3%±1.4%. The germination rate exceeded 90.0% when sown on the 8th day after ripening, reaching 93.3%±3. .8%; the germination rate of seeds in the R7 stage was relatively high, all exceeding 85.0%, but the germination rate of seeds sown on the day of harvest was the lowest, at 87.5%±2.5%, and the germination rate of seeds sown 2 days after ripening was the highest, at 95.0%±2.5%, and the germination rate of seeds sown 4 days after ripening was the second highest, at 94.2%±3.8%; the germination rate of seeds in the R8 stage was average, at 67.5%±2.5%, which was only higher than the 3 treatments of 0 days, 2 days and 4 days after ripening in the R6 stage.

[0061] Table 2 Seed germination rate of Jiaoda 133 seeds with different after-ripening treatments (%) As can be seen from Table 3, the germination rate of seeds of Zhenong 8 at the R6 stage first increased and then decreased slightly with the increase of the number of days after ripening. The germination rate was lowest when sowing on the 0th day after ripening, that is, the day of harvest, was 33.3%±2.9%. The germination rate increased significantly when sowing on the 2nd day after ripening, reaching 97.5%±4.3%. The germination rate was highest when sowing on the 4th and 6th day after ripening, both at 100.0%±0.0%. The germination rate decreased slightly when sowing on the 8th day after ripening, but was still high. The germination rate of seeds in the R7 stage also showed a trend of first increasing and then decreasing with the increase of the number of days after ripening of the plants, and the germination rate was relatively high, all exceeding 90.0%. The germination rate was the highest when sown 4 days after ripening, reaching 99.2%±1.4%, and the germination rate was the lowest when sown 8 days after ripening, at 93.3%±1.4%; the germination rate of seeds in the R8 stage was 80.8%±3.8%, which was only higher than the germination rate on the sowing day of the R6 stage.

[0062] Table 3 Seed germination rate of Zhenong 8 with different after-ripening treatments (%) As shown in Table 4, the seed emergence rate of Sichuan Fresh Bean No. 1 at the R6 stage showed a trend of first increasing and then slightly decreasing with the increase of plant ripening days. The seed emergence rate was the lowest, 33.3%±1.4%, when sown on the day of harvest. The seed emergence rate increased significantly, reaching 94.2%±2.9%, when sown 6 days after ripening, and the highest, 98.3%±1.4%, and the seed emergence rate was second, 95.8%±1.4% when sown 8 days after ripening. The seed emergence rate was relatively high in the R7 stage, all exceeding 90.0%. The seed emergence rate was the highest, reaching 97.5%±2.5%, when sown 4 days after ripening. The seed emergence rate was still high in the R8 stage, reaching 92.5%±2.5%, but was only higher than the two treatments of 0 and 2 days after ripening in the R6 stage.

[0063] Table 4 Seed germination rate of Sichuan Fresh Bean No. 1 under different ripening treatments (%) As shown in Table 5, the germination rate of seeds of Chuandou 155 at the R6 stage showed a trend of first increasing and then decreasing with the increase of the number of days after ripening of the plants. The germination rate was the lowest, 26.7%±3.8%, when sown on the day of harvest, and increased significantly, reaching 90.0%±4.3% when sown 4 days after ripening. The germination rate was the highest, reaching 100.0%±0.0%, and the germination rate was second, 92.5%±2.5% when sown 8 days after ripening. The germination rate of seeds treated with plant after-ripening at the R7 stage was relatively high, all exceeding 90.0%. It showed a trend of gradually decreasing with the increase of the number of days after ripening of the plants. The germination rate was the highest, both reaching 100.0%±0.0% when sown on the day of harvest and 4 days after ripening. The germination rate of seeds at the R8 stage was relatively high, at 95.0%±2.5%.

[0064] Table 5 Seed germination rate of Chuandou 155 under different ripening treatments (%) As shown in Table 6, the germination rate of Gongxiandou No. 4 seeds at the R6 stage increased with the increase of the number of days after the plant ripening. The germination rate was the lowest at 27.5%±2.5% when sown on the day of harvest, and increased significantly at 80.0%±2.5% when sown 4 days after ripening. The germination rate reached 90.0%±0.0% when sown 6 days after ripening, and the highest at 96.7%±3.8% when sown 8 days after ripening. The germination rate of seeds treated with plant after-ripening at the R7 stage exceeded 90.0%, and the germination rate was the highest at 98.3%±1.4% when sown on the day of harvest, showing a gradually decreasing trend with the increase of the number of days after the plant ripening. The germination rate of seeds at the R8 stage was 69.2%±3.8%.

[0065] Table 6 Seed germination rate of Gongxiandou No. 4 under different ripening treatments (%) As shown in Table 7, the germination rate of Gongxiandou No. 5 seeds at the R6 stage showed a trend of first increasing and then slightly decreasing with the increase of the number of days after the plant ripening. The germination rate was the lowest, 52.5%±4.3%, when sown on the day of harvest. The germination rate increased significantly, reaching 80.8%±3.8% when sown 2 days after ripening. The germination rate exceeded 90.0% when sown 4 days after ripening, reaching 93.3±1.4%. The germination rate was the highest, 98.3%±2.9%, when sown 6 days after ripening. The germination rate of seeds treated with plant after-ripening at the R7 stage exceeded 90.0%, and the germination rate was the highest, reaching 100.0%±0.0% when sown 2 days after ripening. The germination rate of seeds at the R8 stage was low, only 40.0%±2.5%.

[0066] Table 7 Seed germination rate of Gongxiandou No. 5 under different ripening treatments (%) As shown in Table 8, the germination rate of seeds of Nanxiandou No. 1 at the R6 stage increased with the increase of the number of days after the plant ripening. The germination rate was the lowest when sown on the day of harvest, only 21.7%±3.8%. The germination rate increased significantly when sown 4 days after ripening, reaching 85.8%±1.4%. The germination rate was the highest when sown 6 and 8 days after ripening, both reaching 100.0%±0.0%. The germination rate of seeds treated with plant after-ripening at the R7 stage exceeded 90.0%, and increased with the increase of the number of days after the plant ripening. The germination rate was the highest when sown 8 days after ripening, reaching 97.5%±2.5%. The germination rate of seeds at the R8 stage was relatively low, at 66.7%±3.8%.

[0067] Table 8 Seed germination rate of Nanxiandou No. 1 under different ripening treatments (%) The results in Tables 2-8 all show that the germination rate of each variety sown on the day of harvest in the R6 stage was the lowest. Except for Gongxiandou No. 5 (the germination rate was 52.5% when sown on the day of harvest), the germination rate of the other varieties sown on the day of harvest was less than 40%. The number of days required for the varieties to obtain a germination rate of more than 80.0% after plant after-ripening in the R6 stage was different, but all the tested varieties could obtain a high germination rate (≥88.3%) after ripening for more than 6 days.

[0068] A high seed emergence rate (≥87.5%) can be obtained after all treatments in the R7 stage. In the actual production process, appropriate ripening days can be treated according to the demand for seeds.

[0069] With the exception of Chuandou 155, the seed germination rates of all tested varieties treated with appropriate after-ripening days at R6 and R7 were higher than those of seeds harvested at R8. The higher seed germination rate of Chuandou 155 at R8 may be due to its being a vegetable and grain variety, resulting in faster seed dehydration than other edible bean varieties.

[0070] The total number of days required for plant after-ripening in the R6 and R7 stages of the seven tested varieties was significantly shortened compared to their growth period in the R8 stage (Table 9). Combined with the germination rates of each variety after plant after-ripening in the R6 and R7 stages (Tables 2-8), in order to obtain seeds with a germination rate of more than 80.0%, Jiaoda 133 can achieve this by plant after-ripening for 6 days in the R6 stage, which can shorten 16 days compared to the harvest in the R8 stage. Zhejiang Agricultural No. 8 can achieve this by plant after-ripening for 2 days in the R6 stage, which can shorten 20 days compared to the harvest in the R8 stage. Sichuan Fresh Bean No. 1 can achieve this by plant after-ripening for 4 days in the R6 stage, which can shorten the harvest in the R8 stage. The harvest time can be shortened by 16 days. Chuandou 155 can achieve this by after-ripening the plants for 4 days in the R6 stage, which can shorten 10 days compared with the harvest at the R8 stage. Gongxiandou No. 4 can achieve this by after-ripening the plants for 4 days in the R6 stage, which can shorten 22 days compared with the harvest at the R8 stage. Gongxiandou No. 5 can achieve this by after-ripening the plants for 2 days in the R6 stage, which can shorten 27 days compared with the harvest at the R8 stage. Nanxiandou No. 1 can achieve this by after-ripening the plants for 4 days in the R6 stage, which can shorten 25 days compared with the harvest at the R8 stage.

[0071] All test varieties can achieve a high germination rate (≥88.3%) after 6 days of plant after-ripening in the R6 stage, and the growth days can be shortened by 8 to 23 days compared with harvesting in the R8 stage; a high germination rate (≥87.5%) can be achieved on the day of harvesting in the R7 stage, and the growth days can be shortened by 4 to 19 days compared with harvesting in the R8 stage.

[0072] Table 9 Differences in growth days between different varieties after ripening treatment and their R8 stage (days) The present invention solves the long-standing technical problem of "poor seed retention effect after spring sowing" for fresh spring soybeans. By subjecting the aboveground parts of fresh spring soybeans harvested in advance to the R6 and R7 stages to after-ripening treatment and conducting a germination rate test on the seeds, the number of after-ripening days required for a high seed germination rate is obtained. Under high temperature conditions in summer, plants harvested in the R6 stage can obtain a high seed germination rate (≥88.3%) after 6 days of after-ripening, and the seed germination rate is generally higher than that of seeds harvested in the R8 stage; plants harvested in the R7 stage can obtain a high seed germination rate (≥87.5%) after after-ripening treatment, and the seed germination rate is generally higher than that of seeds harvested in the R8 stage, solving the long-standing problem of "poor seed retention effect after spring sowing" for fresh spring soybeans.

[0073] As of the patent application date, the seedlings obtained from the germination experiment were very strong.

[0074] The method of the present invention can significantly shorten the growth period of fresh spring soybeans, enabling multi-generation breeding in one year and significantly improving breeding efficiency. The plant after-ripening method improves the germination rate of fresh spring soybean seeds while also shortening the growth period. Plants harvested at the R6 stage achieve a higher germination rate after six days of after-ripening, with the growth period shortened by 8 to 23 days compared to those harvested at the R8 stage. Plants harvested at the R7 stage achieve a higher germination rate after after-ripening, with the growth period shortened by 4 to 19 days compared to those harvested at the R8 stage. This allows for smooth transition to the golden autumn sowing period (mid-to-late July), enabling local two-generation breeding in one year. After the autumn harvest, additional generations can be carried out in Hainan during the winter, thus achieving three-generation breeding in one year in a different location. Compared to the original one-generation breeding method, the breeding process is accelerated by 2-3 times, the breeding period is significantly shortened, and the breeding efficiency is greatly improved.

[0075] The method of the present invention is simple to operate and low in cost. The aboveground parts of fresh spring soybeans harvested at the R6 and R7 stages are placed in a well-ventilated, dry environment indoors for a certain number of days of after-ripening treatment. The maturity of the seeds can then be determined by peeling the pods and observing them. The method can also be used to select an appropriate number of days for after-ripening treatment based on the sowing plan and seed demand. This method is simple and easy for breeders to perform, does not require the use of any equipment, and is very low in cost.

[0076] The present invention shortens the growth period and achieves a higher seed germination rate while also ensuring high seed quality. By the time the aboveground plant is harvested at the R6 and R7 stages, the seeds have completed their basic nutritional growth. After the entire plant is harvested, the plant can continue to provide some nutrients to the ripening grains, allowing them to continue growing. This plant after-ripening prevents problems such as wrinkled, cracked, or moldy grains during the fully ripening stage, while ensuring the essential nutrients required by the seeds, thereby ensuring seed quality and improving the seed germination rate.

[0077] Based on the after-ripening method of the present invention and conventional autumn sowing and southern propagation treatment, the following breeding process can be completed in conventional soybean autumn sowing areas: (1) Planting edible spring soybean hybrid progeny materials in spring (March-April); (2) Harvest the aboveground plants at the full-grain stage, i.e., R6 stage (late June to early July), or the initial ripening stage, i.e., R7 stage (early July to mid-July), and perform after-ripening treatment; (3) The seeds obtained from the after-ripening treatment are planted locally in autumn (sowed in mid-to-late July) for an additional generation, completing local two-generation breeding per year; (4) After the offspring materials of autumn sowing are harvested (late October to early November), they are sent to Hainan for further propagation in winter (late November to early December), completing three generations of off-site propagation in one year; (5) The following year, the offspring materials harvested from the southern breeding (in March) will be transported back to the local area for spring sowing (in March-April), entering the next round of off-site breeding with three generations per year.

[0078] Soybean hybrid offspring materials can generally be stably inherited in the F6 generation. According to the original breeding method of one generation per year, it takes 6 years.

[0079] By adopting plant after-ripening treatment, local "spring sowing + autumn sowing" can achieve two generations of breeding per year, which only takes three years, which is 1 / 2 the time required for one generation of breeding per year.

[0080] By adopting plant after-ripening treatment + autumn sowing + Hainan southern breeding, three generations of breeding in a year can be achieved through "spring sowing + autumn sowing + winter southern breeding" in a different location. It only takes two years, which is 1 / 3 of the time required for one generation of breeding a year, and the breeding efficiency is greatly improved.

[0081] In the description of the present invention, it should be understood that "-" and "~" represent a range between two values, and the range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0082] In the description of the present invention, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0083] In the description of the present invention, the term "about" or "approximately" is used to express the approximate value of a numerical value or range, allowing a certain error to ensure the flexibility and practicality of the description while remaining within an acceptable error range, with the maximum error range not exceeding 10% of the corresponding numerical value or numerical range.

[0084] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for shortening the soybean breeding cycle based on plant after-ripening, characterized in that: Applicable to autumn soybean sowing areas, including the following steps: a) After the soybean plant enters the R6 stage and before entering the R8 stage, the aboveground part of the plant is harvested; b) Place the harvested plants in a ventilated and dry indoor environment for after-ripening; c) After-ripening treatment time is 0 to 8 days; d) After ripening, peel the pods and take out the seeds for sowing or storage.

2. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, characterized in that: In the step a), the soybean plants are spring-sown soybean plants.

3. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 2, characterized in that: The spring sowing time is March to April.

4. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, characterized in that: In the step a), the soybeans are fresh soybeans.

5. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 4, characterized in that: The varieties of fresh soybeans include Jiaoda 133, Zhenong 8, Chuanxiandou 1, Chuandou 155, Gongxiandou 4, Gongxiandou 5 or Nanxiandou 1.

6. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, characterized in that: In step a), when the harvest period is R6, the time for the after-ripening treatment is 4 to 8 days.

7. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, characterized in that: In the step a), when the harvest period is R7, the time for the after-ripening treatment is 0 to 8 days.

8. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, 6 or 7, characterized in that: In the step c), the number of days for after-ripening is determined by a seed germination experiment, and the seed germination rate is not less than 85%.

9. The method for shortening the soybean breeding cycle based on plant after-ripening according to claim 1, characterized in that: In the step d), the sowing is done in autumn, in mid to late July, so as to achieve two generations of breeding per year locally.

10. The method for shortening soybean breeding cycle based on plant after-ripening according to claim 9, characterized in that: After sowing and harvesting in autumn, the seeds are moved to the tropics in the winter of the same year for reproduction and generation, achieving three generations of reproduction in one year.

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