Method for accelerating watermelon breeding process

Abstract

The invention relates to the technical field of watermelon breeding, in particular to a method for accelerating the watermelon breeding process, which comprises the following steps: sampling and dissecting immature watermelon fruits, determining the harvesting time according to the immature embryo development degree of immature watermelon fruit seeds, collecting the immature watermelon fruits within the harvesting time, taking out the seeds, cleaning and airing. The taken seeds are subjected to seed soaking and initiation treatment, then the seeds subjected to seed soaking and initiation treatment are subjected to germination acceleration, germinated seeds are obtained, and the germinated seeds are directly sown in a seedling culture substrate for conventional seedling culture management and protection. Therefore, the seed breeding time between different generations in the watermelon breeding process can be shortened, next generation breeding can be carried out without waiting for complete maturation of the seeds of the previous generation, the breeding process is accelerated, the situation that the breeding process is delayed due to seed malformation, abortion and the like is avoided, the complete structure of the seeds does not need to be damaged, and the breeding efficiency is improved. Sterile culture is not needed, and the operation is simple, convenient and feasible.

Description

Technical Field

[0001] The invention relates to the technical field of watermelon breeding, and in particular to a method for accelerating the watermelon breeding process. Background Art

[0002] Watermelon is an annual climbing vine plant of the genus Citrus in the Cucurbitaceae family. It is one of the world's important horticultural economic crops and is deeply loved by consumers all over the world. With the development of advanced breeding technologies such as molecular markers and gene editing, various watermelon varieties and types continue to emerge, which not only enriches the watermelon consumer market, but also brings breeders the requirement for faster and better variety iteration. Although watermelon breeders can use modern molecular technology principles to quickly locate the target gene and introduce it into the variety that needs to be improved, new germplasm resources (such as genetically engineered plants, hybrid combinations, etc.) still need to go through the seed breeding stage to realize trait expression and variety continuation.

[0003] At present, the existing seed breeding methods, such as the Chinese patent with publication number CN115136889B, disclose a papaya immature seed germination method, which takes out the papaya immature seeds under sterile conditions for tissue culture, and directly grows papaya seedlings through the organogenesis pathway, which overcomes the factor of the existing technology that the immature embryos are induced to form callus tissue by hormones, and papaya seed seedlings can be quickly obtained in a short time, and the germination efficiency of papaya seeds is improved. However, the tissue culture link under sterile conditions in the invention still requires a certain culture time, which is mainly suitable for situations where mature seeds cannot be obtained (such as typhoon damage, etc.), and cannot solve the problem of breeding acceleration.

[0004] How to shorten the seed breeding time between different generations in the watermelon breeding process, so that the next generation can be selected and bred without waiting for the seeds of the previous generation to fully mature, speed up the breeding process, and avoid delays in the breeding process due to seed deformities, abortion, etc., without destroying the intact structure of the seeds, without the need for sterile culture, and with simple and easy operation, has become a technical problem that needs to be broken through.

[0005] In summary, the prior art obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the invention

[0006] In view of the above-mentioned defects, the purpose of the present invention is to provide a method for accelerating the watermelon breeding process, which can shorten the seed breeding time between different generations in the watermelon breeding process, and can carry out the breeding of the next generation without waiting for the seeds of the previous generation to fully mature, thereby accelerating the breeding process and avoiding delays in the breeding process due to seed deformity, abortion, etc., and there is no need to destroy the intact structure of the seeds, no need for sterile culture, and the operation is simple and easy.

[0007] In order to achieve the above object, the present invention provides a method for accelerating the watermelon breeding process, comprising the following steps:

[0008] S1. Determine the harvest time: Sample and dissect the immature watermelon fruits, and determine the harvest time based on the development degree of the immature embryo of the seeds of the immature watermelon fruits.

[0009] S2. Collecting seeds: According to the harvesting time determined in S1, collect the immature watermelon fruits within the harvesting time, take out the seeds, wash and dry them.

[0010] S3. Seed soaking and initiation treatment: The seeds collected in S2 are soaked in a gibberellin solution for initiation treatment.

[0011] S4. Germination and sowing: The seeds treated by seed soaking and priming in S3 are germinated to obtain germinated seeds, and the germinated seeds are directly sown in the seedling medium for conventional seedling care.

[0012] According to the method for accelerating the watermelon breeding process of the present invention, the harvesting time in step S1 is the shortest time from the completion of pollination of the female flowers to the completion of differentiation of the cotyledons of the immature watermelon seeds and the ability to germinate.

[0013] According to the method for accelerating the watermelon breeding process of the present invention, the harvesting time is 15 to 18 days after the female flowers are pollinated.

[0014] According to the method for accelerating the watermelon breeding process of the present invention, the optimal harvesting time is 18 days.

[0015] According to the method for accelerating the watermelon breeding process of the present invention, in the step S3, the condition for the seed soaking induction treatment is that the gibberellin concentration is 50 to 100 mg / L, and the time for the seed soaking induction treatment is 30 to 60 minutes.

[0016] According to the method for accelerating the watermelon breeding process of the present invention, the optimal conditions for the seed soaking induction treatment are a gibberellin concentration of 50 mg / L and a seed soaking induction treatment time of 30 minutes.

[0017] According to the method for accelerating the watermelon breeding process of the present invention, in the step S4, a constant temperature germination method is adopted during germination, and the temperature is 30°C.

[0018] The object of the present invention is to provide a method for accelerating the watermelon breeding process. According to the development degree of immature watermelon fruit seeds, the shortest time from pollination to the formation of cotyledon embryos is determined, the harvesting time of watermelon seeds is shortened, the harvesting is faster than that in the prior art, and the next generation breeding can be carried out without waiting for the seeds of the previous generation to be fully mature, thereby accelerating the breeding process; when the seeds are harvested, the immature embryos have basically developed and have the potential to develop into normal and complete plants, thereby avoiding delays in the breeding process due to situations such as seed deformity and abortion, and there is no need to destroy the complete structure of the seeds, no need for aseptic culture, and the operation is simple and easy. In summary, the beneficial effects of the present invention are: it can shorten the seed breeding time between different generations in the watermelon breeding process, it is not necessary to wait for the seeds of the previous generation to be fully mature before the next generation breeding can be carried out, the breeding process is accelerated, and the breeding process is avoided due to situations such as seed deformity and abortion, and there is no need to destroy the complete structure of the seeds, no need for aseptic culture, and the operation is simple and easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a statistical chart of the germination rate of watermelon seeds under pollination days and gibberellin treatment;

[0020] Figure 2 Shown are the germination conditions of seeds harvested at different times. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "top / bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The present invention provides a method for accelerating the watermelon breeding process, comprising the following steps:

[0025] S1. Determine the harvest time: Sample and dissect the immature watermelon fruits, observe the development degree of the immature watermelon fruit seed embryos, determine the shortest time from pollination to the formation of cotyledon embryos, and use this as the harvest time for the immature watermelon fruits (the harvest time is the shortest time from the completion of pollination of the female flowers to the completion of the differentiation of the cotyledons of the immature watermelon seed embryos and the ability to germinate).

[0026] The harvest time is 15 to 18 days after the female flowers are pollinated.

[0027] S2. Collecting seeds: According to the harvesting time determined in S1, collect the immature watermelon fruits within the harvesting time, take out the seeds, wash and dry them.

[0028] S3. Seed soaking and initiation treatment: The seeds collected in S2 are soaked in a gibberellin solution for initiation treatment.

[0029] The concentration of gibberellin is 50-100 mg / L, and the time for seed soaking initiation treatment is 30-60 minutes.

[0030] S4. Germination and sowing: The seeds treated by seed soaking and priming in S3 are germinated to obtain germinated seeds, and the germinated seeds are directly sown in the seedling medium for conventional seedling care.

[0031] The germination was carried out at a constant temperature of 30°C.

[0032] To verify the breeding method of the present invention, the present invention conducted the following experiments:

[0033] Take seeds of watermelon variety G42 (this variety is selected and bred by Huaiyin Agricultural Science Institute in Xuhuai District, Jiangsu Province, plant variety right application number 20241003856, and the seeds are provided by the breeder), and grow seedlings in a 50-hole plug tray in a nursery room; when the first true leaf of the watermelon emerges, use pumpkin rootstock with flattened cotyledons for grafting; when the grafted seedlings grow to three leaves and one heart, they are planted in a greenhouse, double-vine pruning is performed, and the second female flower is used for pollination.

[0034] The immature watermelon fruits are harvested 12 days, 15 days and 18 days after pollination (usually watermelon seeds are fully mature about 30 days after pollination. In order to speed up the breeding process, the present invention selects seeds that form cotyledon embryos as seeds), and the immature seeds of the harvested immature watermelon fruits are taken out, washed and dried to obtain seeds at different days after pollination.

[0035] Seeds 12 days, 15 days and 18 days after pollination were grouped according to distilled water (CK), gibberellin (GA) 50 mg / L, gibberellin 50 mg / L, gibberellin 100 mg / L and gibberellin 100 mg / L, respectively. Two soaking time gradients (30 min and 60 min) were set for each group. Twelve seeds were used in each group, and each group was repeated 5 times.

[0036] Place absorbent paper at the bottom of the culture dish, soak the absorbent paper with distilled water, evenly place the seeds that have been primed by seed soaking on the absorbent paper soaked with distilled water, cover the culture dish lid, place the culture dish flat in the incubator, set the temperature to 30°C, and protect from light throughout the process. Starting from 36 hours after constant temperature cultivation, count the number of sprouts every 12 hours, and calculate the germination rate as the ratio of the cumulative number of germinated seeds after 120 hours of constant temperature cultivation to the number of treated seeds.

[0037] See also Figure 2 , where AC is the situation of seeds harvested 12 days, 15 days and 18 days after pollination after constant temperature culture and germination for 24 hours, DF is the situation of seeds harvested 12 days, 15 days and 18 days after pollination after constant temperature culture and germination for 72 hours, because the seeds 12 days after pollination are all germinated, the specific data are omitted in the table below, and the germination of seeds 15 days and 18 days after pollination is statistically analyzed, and the obtained data are shown in Tables 1 and 2 below:

[0038] Table 1 Germination of seeds collected 15 days after pollination

[0039]

[0040]

[0041] Table 2 Germination of seeds harvested 18 days after pollination

[0042]

[0043]

[0044] The data in Table 1 and Table 2 were sorted to obtain the pollination days and the germination rate of watermelon seeds under gibberellin treatment, see Table 3:

[0045] Table 3 Seed germination rate

[0046]

[0047] In Table 3, different lowercase letters indicate that there were significant differences in the germination rates of watermelon seeds treated with different gibberellins at the same pollination days level (p < 0.05); different uppercase letters in the table indicate that there were significant differences in the germination rates of watermelon seeds treated with different pollination days at the same gibberellin treatment (p < 0.05).

[0048] See also Figure 1 , the data in Table 3 were further processed to obtain the statistical graph of pollination days and watermelon seed germination rate under gibberellin treatment ( Figure 1 In the data, * indicates P value < 0.05, i.e., the statistical significance level is 95%, ** indicates P value < 0.01, i.e., the statistical significance level is 99%, ns indicates no statistical significance). It can be seen that under the premise of ensuring normal germination and growth of seeds, the best time to harvest seeds is 18 days (if seeds after 18 days are selected, the breeding time will be extended, and if seeds before 18 days are selected, it will affect the germination and growth of seeds). The best conditions for seed soaking induction treatment are a gibberellin concentration of 50 mg / L and a seed soaking induction treatment time of 30 min.

[0049] It should be pointed out that the later the seeds are harvested, the higher their development degree may be, but the effect of accelerating the breeding process will be relatively reduced. Therefore, under the premise of comprehensively considering the urgency of the breeding project and the adequacy of funds, selecting 18-day-old seeds for harvesting can not only ensure a certain germination rate, but also speed up the breeding process and save costs.

[0050] The present invention provides a method for accelerating the watermelon breeding process. According to the development degree of immature watermelon fruit seeds, the shortest time from pollination to the formation of cotyledon embryos is determined, the harvesting time of watermelon seeds is shortened, and the harvesting is faster than that in the prior art, which can accelerate seed breeding and the breeding process; when the seeds are harvested, the immature embryos have basically completed their development and have the potential to develop into normal and complete plants, so that the breeding process is avoided from being delayed due to the occurrence of seed deformity, abortion and the like, and the complete structure of the seeds does not need to be destroyed, and aseptic culture is not required, and the operation is simple and easy. In summary, the present invention has the beneficial effects of shortening the seed breeding time between different generations in the watermelon breeding process, and the next generation breeding can be carried out without waiting for the seeds of the previous generation to be fully mature, accelerating the breeding process, avoiding the delay of the breeding process due to the occurrence of seed deformity, abortion and the like, and the complete structure of the seeds does not need to be destroyed, and aseptic culture is not required, and the operation is simple and easy.

[0051] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for accelerating watermelon breeding process, characterized in that: The steps include: S1. Determine the harvest time: sample and dissect the immature watermelon fruit, and determine the harvest time according to the development degree of the immature embryo of the seed of the immature watermelon fruit; S2. Collecting seeds: According to the harvesting time determined in S1, collect immature watermelon fruits within the harvesting time, remove the seeds, wash and dry them; S3 seed soaking initiation treatment: The seeds collected in S2 were soaked in a gibberellin solution to initiate treatment; S4. Germination and sowing: The seeds treated by seed soaking and priming in S3 are germinated to obtain germinated seeds, and the germinated seeds are directly sown in the seedling medium for conventional seedling care.

2. The method for accelerating watermelon breeding process according to claim 1, characterized in that: The harvesting time in step S1 is the shortest time from the completion of pollination of the female flowers to the completion of differentiation of the cotyledons of the immature watermelon seeds and the completion of germination ability.

3. The method for accelerating watermelon breeding process according to claim 2, characterized in that: The harvesting time is 15 to 18 days after the female flowers are pollinated.

4. The method for accelerating watermelon breeding process according to claim 3, characterized in that: The optimal harvesting time is 18 days.

5. The method for accelerating watermelon breeding process according to claim 1, characterized in that: In the step S3, the condition for the seed soaking initiation treatment is that the gibberellin concentration is 50 to 100 mg / L, and the time for the seed soaking initiation treatment is 30 to 60 minutes.

6. The method for accelerating watermelon breeding process according to claim 5, characterized in that: The optimal conditions for the seed soaking initiation treatment are a gibberellin concentration of 50 mg / L and a seed soaking initiation treatment time of 30 min.

7. The method for accelerating watermelon breeding process according to claim 1, characterized in that: In the step S4, the germination is carried out at a constant temperature of 30°C.

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