阅读说明：本技术 一种混播混收的杂交水稻制种方法 (Hybrid rice seed production method with mixed sowing and mixed harvesting ) 是由 朱爱儒 朱仁山 戴继洪 于 2020-07-12 设计创作，主要内容包括：本发明涉及一种混播混收的杂交水稻制种方法,包括以下步骤：将播始历期相近、粒型不同的父本种子和母本种子按比例混合浸种,得到湿润混合种子；向湿润混合种子中加入未浸种的父本种子,充分混匀,得到直播种子；将所述直播种子直播于大田中；进行田间管理,待水稻结种后,收获水稻种子；通过粒型分选从水稻种子中分离得到杂交水稻种子。本发明将播始历期相近、粒型不同的父本和母本混播于田中来制备杂交水稻种子,混收后通过粒型分选来将父本结的种子和杂交水稻种子分开。本发明在播种时部分父本种子没有浸种,从效果上延迟了未浸种父本的开花时间3-5天,形成了两期父本,使得总父本的花期得以延长,从而保证总父本的花期覆盖母本的花期。(The invention relates to a hybrid rice seed production method by mixed sowing and mixed harvesting, which comprises the following steps: mixing and soaking the male parent seeds and the female parent seeds which have similar sowing initial periods and different grain types according to a proportion to obtain wet mixed seeds; adding the male parent seeds which are not soaked into the wet mixed seeds, and fully and uniformly mixing to obtain direct-seeding seeds; directly seeding the direct seeding seed in a field; performing field management, and harvesting rice seeds after the rice seeds are grown; separating the hybrid rice seeds from the rice seeds by grain type sorting. The invention mixedly sows the male parent and the female parent which have similar sowing beginning and duration and different grain types in a field to prepare the hybrid rice seed, and separates the male parent seed from the hybrid rice seed by grain type sorting after mixedly harvesting. In the invention, partial male parent seeds are not soaked in the seeds during sowing, the flowering time of the male parent without soaking in the seeds is delayed for 3-5 days from the effect, and the two-stage male parent is formed, so that the flowering phase of the total male parent is prolonged, and the flowering phase of the total male parent is ensured to cover that of the female parent.)

1. A hybrid rice seed production method of mixed sowing and mixed harvesting is characterized by comprising the following steps:

s1: mixing and soaking the male parent seeds and the female parent seeds which have similar sowing initial periods and different grain types according to a proportion to obtain wet mixed seeds;

s2: adding the male parent seeds which are not soaked into the wet mixed seeds, and fully and uniformly mixing to obtain direct-seeding seeds;

s3: directly seeding the direct seeding seed in a field;

s4: performing field management, and harvesting rice seeds after the rice seeds are grown;

s5: separating the hybrid rice seeds from the rice seeds by grain type sorting.

2. The method for producing hybrid rice seeds as claimed in claim 1, wherein in S1, the ratio of male parent seeds to female parent seeds is 1:5-20 during seed soaking.

3. The method for producing hybrid rice seeds as claimed in claim 1, wherein the seed soaking time in S1 is 18-36 hours.

4. The method for producing hybrid rice seeds as claimed in claim 1, wherein the ratio of the amount of the non-seeded male parent seed to the amount of the seeded male parent seed added in S2 is 1: 0.5-2.

5. The method for producing hybrid rice seeds as claimed in claim 1, wherein in S3, the row spacing is 18-20cm and the plant spacing is 13-18cm during direct seeding.

6. The method for producing hybrid rice seeds as claimed in claim 1, wherein in S4, artificial pollination is used when the male parent is heading.

7. The method for producing hybrid rice seeds as claimed in claim 6, wherein in S4, pollination is carried out by unmanned aerial vehicle method.

8. The method for producing hybrid rice seeds as claimed in claim 1, wherein the period of time of the sowing beginning of the male parent and the period of time of the sowing beginning of the female parent differ by no more than 5 days.

9. The method for producing hybrid rice seeds as claimed in any one of claims 1 to 8, wherein the grain type is the size, color, shape or a combination of any two or more thereof of the rice seeds.

Technical Field

The invention relates to the field of hybrid rice breeding and mechanized seed production, in particular to a hybrid rice seed production method with mixed sowing and mixed harvesting.

Background

The rice is a main grain crop in China, the annual planting area of the current rice is about 4.3-4.4 hundred million acres, wherein the annual planting area of the hybrid rice is about 2.2 hundred million acres, which accounts for more than 50% of the total rice area, and the rice greatly contributes to the yield increase and the grain safety of the rice in China.

The principle of hybrid rice is: two rice varieties which have certain difference in heredity and can complement excellent characters are selected for hybridization, and the obtained first generation hybrid has heterosis. The first generation hybrid is used for agricultural planting, has strong stress resistance and high yield, and is suitable for mechanization. The seeds obtained by selfing hybrid rice cannot maintain the heterosis, so that the hybrid rice seeds for agricultural production obtained by ordinary farmers must be obtained by the hybridization of two parents, and the process is called seed production.

The seed production of hybrid rice is one of the most critical links in agricultural production. The flower season meeting of the male parent and the female parent is the precondition of ensuring high quality and high yield of the seed production, however, the flower season meeting of the male parent and the female parent is also an important limiting factor of the seed production. As the male parent and the female parent belong to different strains, the flowering phases of the male parent and the female parent are different, generally speaking, the flowering phases of the male parent are short and concentrated, the flowering phases of the female parent are long and dispersed, and the heading and flowering time of the male parent and the female parent is different by 7-40 days. Therefore, in order to meet the florescence, adjustment is often required during planting according to the florescence characteristics of the parental combination, including determining the sowing difference period, predicting the florescence, adjusting the vegetative or reproductive growth period through water and fertilizer management, and the like.

However, these methods greatly increase the production of seeds on the one hand and are also influenced by human factors (e.g., sowing error, flowering prediction inaccuracy, too many or too few parent seedlings, improper field management, etc.) and non-human controllable factors (e.g., weather, plant diseases and insect pests, soil moisture, etc.) on the other hand.

At present, many researches and applications have been carried out to screen out the combination of parents with similar broadcasting-beginning period, but in order to pollinate female flowers as much as possible to realize high yield, the florescence of the male parent should be ensured to completely cover the female parent. This requires that the sowing initial period of the male parent is shorter than that of the female parent, the flowering period is longer than that of the female parent, and the flowering period of the female parent is completely in the flowering period of the male parent, which is too harsh to limit the combination of male and female parents of hybrid rice, and is not favorable for obtaining high-quality hybrid rice.

To overcome this difficulty, some breeders have grown two-stage male parents to cover the female parent completely in the flowering phase. For example, during transplanting, the female parent and the first-stage male parent are transplanted first, one row is reserved beside the first-stage male parent in each row for the second-stage male parent, and the second-stage male parent is transplanted after a few days. Although this method can ensure that the florescence of the male parent completely covers the florescence of the female parent, it has two disadvantages. One is increased labor and the other is not conducive to mechanized operation.

Future agriculture is necessarily mechanized and automated, so a new seed production method is needed to be provided for breeders, the high-yield requirement and the mechanized requirement are met, and the selection of parents and parents is not too harsh.

Disclosure of Invention

In order to solve the problems, the invention provides a hybrid rice seed production method of a synchronous mixed sowing parent, which comprises the following steps:

s1: mixing and soaking the male parent seeds and the female parent seeds which have similar sowing initial periods and different grain types according to a proportion to obtain wet mixed seeds;

s2: adding the male parent seeds which are not soaked into the wet mixed seeds, and fully and uniformly mixing to obtain direct-seeding seeds;

s3: directly seeding the direct seeding seed in a field;

s4: performing field management, and harvesting rice seeds after the rice seeds are grown;

s5: separating the hybrid rice seeds from the rice seeds by grain type sorting.

The hybrid rice seeds are prepared by sowing male parents and female parents which have similar sowing initial period and flowering period and different grain types in a field in a mixed manner, the male parents and the hybrid rice seeds are harvested in a mixed manner, and the seeds grown on the male parents and the hybrid rice seeds are separated by grain type sorting. In order to improve the yield, partial male parent seeds are not soaked in the seeds during sowing, and as a result, the flowering time of the male parent which is not soaked in the seeds is delayed for 3-5 days in effect, and the male parent with two or more stages is formed, so that the flowering phase of the total male parent is prolonged, and the flowering phase of the total male parent is ensured to cover that of the female parent.

In a specific embodiment, in S1, the ratio of the paternal seed to the maternal seed is 1:5-20 during seed soaking.

In one embodiment, in S1, the seed soaking time is 18 to 36 hours.

In a particular embodiment, the ratio of the amount of non-steeped male parent seed to the amount of steeped male parent seed added in S2 is 1: 0.5-2.

By optimizing the proportion of the male parent and the female parent, the female parent can be planted as many as possible in the field under the condition of keeping complete pollination so as to obtain hybrid rice seeds as many as possible. Preferably, the ratio of the amount of non-steeped male seed to the amount of steeped male seed added in S2 is 1: 1.

In a preferred embodiment, in S3, the row spacing is 18-20cm and the plant spacing is 13-18cm during direct seeding. The thinning can also be carried out in the field management process, and the proper spacing is a means for improving the rice yield. In the field, direct seeding can be carried out by using a mechanical precision hole direct seeding machine.

In a preferred embodiment, in S4, artificial pollination is used when the male parents are spiked.

In a specific embodiment, pollination is performed using the unmanned aerial vehicle method. Can use unmanned aerial vehicle to pollinate when the parent book begins to ear, blossoming every day.

In a preferred embodiment, the parental control books have a calendar date that differs by no more than 5 days to ensure that the parental control books have florescence.

In a specific embodiment, the grain type is the size, color, shape, or a combination of any two or more thereof of the rice seed. For example, a large-sized male parent (about 30g in thousand grain weight) and a small-sized female parent (about 15g in thousand grain weight) can be selected for seed production, and among seeds that are produced at the time of harvest, the large-sized seed is a male parent seed, and the small-sized seed is a hybrid rice seed, and the large-sized seed and the small-sized seed can be easily separated by size grain type sorting.

Through the seed production method, the hybrid rice seed production from the hybrid direct seeding of the parents, the field management and plant protection, the pollination of the parents, the mixed harvesting and the selection to the seed separation can be mechanized, and the whole process of the hybrid rice seed production can be completely mechanized.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

"onset of broadcasting" means the number of days from sowing to heading of rice.

"flowering duration" refers to the number of days from the first time a flower is opened, the female and male stamens are exposed from the flower perianth, until the flower is completely withered and all the stamens or pistils are inactive.

The 'land preparation' refers to planting the parents of the hybrid rice and hybridizing the parents to obtain the location of the hybrid rice seeds or a place with the climate and hydrology similar to the location.

The pollination means that the stigma of the female parent of the hybrid rice receives the pollen of the male parent to finish the fertilization.

The term "grain type" refers to rice seeds, wherein the male parent is large (about 30g per thousand grains) and the small grain is female parent (about 15g per thousand grains).

The 'big and small grain separating seed classificator' is a hybrid rice seed classificator which can remove impurities and blighted grains in seeds and then carry out big and small grain sorting.

Detailed Description

The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

The sterile line cultured by the team is selected, the sowing initial period is 79 days in Hubei, the flowering period is 8 days, the flowering time is 9:00a.m. -11:30a.m, the plant height is about 78cm, the loose and moderate effect is achieved, the leaf color is light green, the sword leaf is upright, the tillering force is strong, the neck wrapping degree is small, the spike layer is neat, the flowering habit is good, the flowering is concentrated, the stigma is large, the color is colorless, the double exposure rate is high, the glume opening included angle is large, the glume closing is good, the outcrossing maturing rate is high, and the thousand seeds are about 15 g. Selecting a commonly used restoring line, wherein the sowing beginning calendar period is 81 days, the flowering period is 8 days, and the flowering time is 9: 30a.m. -11:30a.m, and about 30g of thousand seeds. The initial period of the restorer line is 2 days longer than that of the sterile line, the lengths of the florescence are the same, and better florescence meeting can be expected. The following seed production tests were performed:

Seed production test 1: in 2016, the seeds are produced in the Luo field in Hubei, the area is 0.5 mu, the male parents are planted in two periods of soaking, the male parents are planted in the first period 6 days earlier than the female parents, the male parents are planted in the second period 7 days later than the male parents in the first period, the seedlings are planted manually, the female parents are planted in 5 months and 22 days, the female parents are planted in 12 months and are aligned with ears, the flowering period of the female parents meets the male parents in the second period better, and the yield of hybrid seeds per mu is.

Seed production test 2: in 2017, 5 mu of seedlings are produced in Wene water in Hubei province, male parents are sequentially soaked in seeds and are mixed and directly sown in a certain proportion, the mixed and direct sowing is carried out in the same period of 5 months and 20 days, and when the seedlings of the male parents grow to 4-5 leaves, thinning is carried out, so that the reasonable density of the male parents and the female parents is ensured. And then continuing to carry out conventional field management. The result shows that the male parent completely covers the female parent in the flowering phase, the flowering phases meet better, the female parent is flush with the ear in 7 months and 30 days, the female parent is harvested in a mixed mode in 8 months and 15 days, the harvesting is carried out, the drying is carried out, the selection is carried out, the separation of large grains and small grains is carried out, and the yield per mu of the small-grain hybrid seeds is 432 jin.

Seed production test 3: in 2018, breeding 20 mu in water in xi province in large area, all according to mechanized mixed direct seeding in a field, plant protection by an unmanned aerial vehicle, artificial pollination, mixed harvesting by a large-scale harvester, drying, fine selection and sorting of large grains, and obtaining the small-grain hybrid rice seeds with the yield per mu of 420 jin and the seed purity of more than 99 percent.

Therefore, the mixed sowing and mixed harvesting seed production method can ensure the yield of the hybrid rice seeds and can perform fully mechanical sowing, management and harvesting.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.