阅读说明：本技术 一种培育氮素高效利用粳稻品种的育种方法 (Breeding method for cultivating japonica rice variety with high-efficiency utilization of nitrogen ) 是由 杨军 龚红兵 胡庆峰 杜灿灿 曾生元 李闯 孙立亭 林添资 景德道 余波 钱华飞 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种培育氮素高效利用粳稻品种的育种方法,以早生快发的穗粒兼顾型粳稻品种作母本,与穗粒兼顾型粳稻品种作父本杂交,F-(0)-F-(3)稀直播种植,混收留种；F-(4)以上世代稀播育秧,单本移栽种植,单收留种。通过苗肥和基蘖肥减氮,以播后25-30d单株平均茎蘖数和成熟期单株平均成穗数为选择压,按照系谱法F-(5)起建立株系,优中选优,直至获得稳定品系提升参加各级中间试验。本发明培育出的粳稻品种能在苗肥和基蘖肥大幅“减氮”的情况下,实现培育壮秧,早生快发、早够苗,确保有效分蘖期内达到适宜茎蘖数,最终实现水稻生产“减肥”、“减药”提质增效的目的。(The invention discloses a breeding method for cultivating a japonica rice variety with high-efficiency utilization of nitrogen, which comprises the steps of hybridizing a japonica rice variety with early-growing and quick-growing spike-grain compromise type serving as a female parent and a japonica rice variety with spike-grain compromise type serving as a male parent, and F 0 ‑F 3 Planting in a direct seeding mode, and collecting and reserving seeds in a mixed mode; f 4 The seedling raising is carried out in the rare sowing of the generations, the transplanting and planting are carried out singly, and the seeds are collected and reserved singly. Reducing nitrogen through seedling fertilizer and basal tiller fertilizer, selecting the average tiller number of the single plant after sowing for 25-30d and the average spike number of the single plant in mature period as selection pressure, and performing a spectrum method F 5 And (4) establishing a strain, and selecting the best from the best until a stable strain is obtained, and promoting the strain to participate in all levels of intermediate tests. The japonica rice variety cultivated by the method can realize cultivation of strong seedlings, early growth, fast growth and early seedling, ensures that the proper number of stem tillers is reached in an effective tillering period and finally realizes the purposes of weight reduction, medicine reduction, quality improvement and efficiency improvement in rice production under the condition of great nitrogen reduction of seedling fertilizer and basal tillering fertilizer.)

1. A breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency is characterized by comprising the following steps:

A) selection of parents and F₀Configuration: hybridizing the early-growing and fast-growing panicle grain compatible japonica rice variety serving as a female parent and the panicle grain compatible japonica rice variety serving as a male parent to obtain F₀；

B) F is to be₀Directly seeding in the middle and lower reaches of Yangtze river at the time of 5 months 15 days-5 months 20 days to obtain F₁(ii) a Randomly investigating the number of tillers of more than or equal to 30 seedlings 25-30 days after sowing, eliminating the combination with low average number of tillers of single plants, and selecting and retaining the best stem tillers by applying a pedigree method during maturationWell combined, mixed harvested seeds are reserved to obtain F₂；

C) F is to be₂In Hainan Ling water, seeding in 12 months 25-12 months 30 days to ensure the seedling to be more than 2000, pulling out weak seedlings with few stem tillers of a single plant 25-30 days after seeding, selecting excellent individuals with a large spike number of the single plant during maturation, and harvesting and reserving seeds in a mixed manner to obtain F₃；

D) F is to be₃In the middle and lower reaches of Yangtze river, the seedlings are sowed in a sparse direct way in 6 months, 5 days to 6 months and 10 days, more than 2000 seedlings are ensured to be grown, weak seedlings with few stem tillers of a single plant are pulled out 25 to 30 days after sowing, excellent individuals with a large spike number of the single plant are selected and left in the mature period, and mixed harvest and seed reservation are carried out to obtain F₄；

E) F is to be₄Thinly sowing and raising seedlings in the Yannan Ling water at 25-12 months and 30 days, transplanting and planting, removing weak seedlings with few tillers of a single plant 25-30 days after sowing, transplanting the single plant, selecting and reserving a good single plant with a large number of spikes of the single plant during maturation, and harvesting and reserving seeds to obtain F₅；

F) From F₅Establishing strains, thinly sowing and raising seedlings in the middle and downstream areas of Yangtze river within the period of 5 months and 15 days to 5 months and 20 days, transplanting and planting, randomly investigating the number of tillers of more than or equal to 30 seedlings after sowing for 25-30 days, eliminating the strains with small average number of tillers of a single plant, transplanting the strains with large average number of tillers of a single plant, selecting excellent single plants with large spike number of the single plant during maturation, and collecting and reserving the seeds to obtain F₆；

G)F₆And if the later generations are still separated, continuing to select the best from the best according to the steps E) and F) until obtaining a stable strain and promoting the stable strain to participate in the middle test of each level.

2. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in the step A), the female parent is a pre-growing and quick-growing spike grain compatible japonica rice variety, and specifically, the japonica rice variety is sown in the middle and lower reaches of Yangtze river within 5 months and 15 days and within 5 months and 20 days, the dosage of the nitrogen fertilizer for the seedling is 7-8kg, the transplanting is carried out on a single plant, the planting density is 13-14cm multiplied by 24-26cm, the dosage of the nitrogen fertilizer for the tiller is 14-15kg, the average tiller number of a single plant after the planting is 20d is more than or equal to 8, the total glume amount per mu is more than or equal to 3000 ten thousand at maturity, the maturing rate is more than or equal to 90%, and the thousand-grain weight is more than or equal to 25 g.

3. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in the step A), the male parent is a panicle grain compatible japonica rice variety, and specifically, a variety with the total glume flower amount of more than or equal to 2800 ten thousand, the maturing rate of more than or equal to 90 percent and the thousand grain weight of more than or equal to 25g is selected for planting in an appropriate ecological region.

4. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in step B), F₀The seeding quantity of the dilute direct seeding planting is 3-4 kg/mu; f₁Mixing the remaining seeds to obtain F₂The method specifically comprises the steps of reducing the nitrogen dosage of the seedling fertilizer by 40-50% in a same ratio to 3-4kg, randomly investigating the number of tillers of seedlings larger than or equal to 30 days after sowing for 25-30 days, eliminating the combination of which the average number of tillers of a single plant is smaller than or equal to 2, selecting and reserving an excellent combination by applying a pedigree method during maturation, and harvesting and reserving seeds in a mixed mode.

5. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in step C), F₂Planting in a direct seeding mode, and harvesting and reserving seeds in a mixed mode to obtain F₃The specific seeding rate is 3-4 kg/mu, the seed consumption is 60-70g, and the seeding area is 13-15m²Ensuring that more than 2000 plants are grown; 3-4kg of seedling fertilizer nitrogen consumption which is reduced by 40-50% in a same ratio, pulling out weak seedlings with the number of single plant tillers less than or equal to 2 after sowing for 25-30 days, managing the field with other direct seeding fields, selecting excellent individuals with the single plant spike number more than or equal to 5 when the seedlings are mature, and harvesting and reserving seeds in a mixed mode.

6. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in step D), F₃Planting in a direct seeding mode, and harvesting and reserving seeds in a mixed mode to obtain F₄The specific seeding rate is 3-4 kg/mu, the seed consumption is 60-70g, and the seeding area is 13-15m²Ensuring that more than 2000 plants are grown; 3-4kg of seedling fertilizer nitrogen which is reduced by 40-50% in terms of same ratio, pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 after sowing for 25-30d, selecting excellent individuals with the number of spikes of the single plant being more than or equal to 7 when the seedlings are mature, and harvesting and reserving seeds in a mixed mode.

7.The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in step E), F₄Thin sowing for raising seedlings, transplanting for planting, and collecting seeds singly, specifically, the seeding amount of the seedling bed is 9-10 kg/mu, the seed consumption is 60-70g, and the seeding area is 4-5m²3-4kg of seedling fertilizer nitrogen which is reduced by 40-50% in terms of dosage by same ratio, pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 after sowing for 25-30d, transplanting the weak seedlings singly, 10-11kg of seedling fertilizer nitrogen which is reduced by 30-40% in terms of dosage by same ratio in a transplanting field, selecting good single plants with the number of grown single plants being more than or equal to 8 when the nitrogen dosage of the scion grains is the same as that of other transplanting fields, and harvesting and reserving the seeds singly.

8. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: in step F), F₅Performing thin sowing and seedling raising in different branches, and transplanting and planting, wherein the sowing quantity is 9-10 kg/mu; reducing the nitrogen dosage of the seedling fertilizer by 40-50% in a same ratio to 3-4kg, randomly investigating the tiller number of more than or equal to 30 seedlings after sowing for 25-30 days, eliminating the plant line with the average tiller number of a single plant being less than or equal to 2, transplanting the plant line with the average tiller number of the single plant being more than or equal to 2, transplanting the plant line singly, reducing the nitrogen dosage of the tillering fertilizer of the basal tiller of the transplanted field by 30-40% in a same ratio to 10-11kg, using the nitrogen dosage of the spike fertilizer to the other transplanted fields, selecting and reserving the excellent single plant with the spike number of more than or equal to 10 of the single plant during maturation, and harvesting and reserving the seeds singly to obtain F₆。

9. The breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency according to claim 1, characterized in that: the excellent single plants in the step G) are single plants with the average spike forming number of more than or equal to 8 in the southern Hainan Lingshui and the average spike forming number of more than or equal to 10 in the middle and lower reaches of Yangtze river.

Technical Field

The invention relates to the field of breeding methods, in particular to a breeding method for cultivating a japonica rice variety with high-efficiency utilization of nitrogen.

Background

Nitrogen, phosphorus and potassium are major elements necessary for the growth and development of rice, particularly nitrogen, and the application amount of nitrogen is the largest in the whole life of rice. The yield of japonica rice in the middle and lower Yangtze river is 600kg per mu, the nitrogen dosage is generally 18-20kg per mu, on the basis, the yield per unit is improved along with the increase of the nitrogen dosage, and then the nitrogen application amount per mu is increased along with the increase of the nitrogen dosage in pursuit of high yield and ultrahigh yield. Although the application of more nitrogen fertilizers is beneficial to high yield and ultrahigh yield, the nitrogen yield increasing effect and the input-output ratio are continuously reduced along with the improvement of the nitrogen input level, in addition, the nitrogen utilization rate is only 30% -35%, the surplus and lost nitrogen easily causes water eutrophication, the environment pollution of a large-area farmland is caused, and the excessive use amount of the nitrogen also causes the rice to be greedy, overgrown and influence fructify. Therefore, the investment of high nitrogen level is not beneficial to environmental protection and the safety, high quality and high efficiency of rice production.

The fertilizer applied 30 days after the rice is sowed (in the seedling bed period) is commonly called 'seedling fertilizer'. The seedling fertilizer is generally used for 2-3 times, and the nitrogen dosage is 7-10 kg/mu. "half rice is well-planted", strong seedling is the basis of high yield and super high yield, and the main function of seedling fertilizer is to cultivate strong seedling with tiller, which lays the foundation for high yield.

The nitrogen applied in the rice field stage mainly comprises two stages, wherein the first stage is named as tiller fertilizer and mainly used for promoting the vegetative growth and tillering of the rice, and the second stage is named as spike grain fertilizer and mainly used for promoting reproductive growth and grain filling and fructification. The ratio of the tiller fertilizer to the panicle grain fertilizer of japonica rice in the middle and lower reaches of Yangtze river varies from 5:5 to 7:3 according to the difference of soil fertility, cultivation level and target yield. The spike grain fertilizer directly acts on the reproductive growth of rice and the grain filling and fructification, and the utilization efficiency and the input-output ratio are far greater than those of the basal tiller fertilizer, so that on the premise of ensuring that a certain amount of nitrogen is input as the spike grain fertilizer, the dosage of the basal tiller fertilizer is reduced, the occupation ratio of the spike grain fertilizer is improved, the input of the total nitrogen amount of the rice in one life is reduced, the utilization efficiency of the nitrogen can be effectively improved, and the purposes of nitrogen reduction and efficiency improvement in rice production are achieved.

The rice yield is composed of four basic factors of spike number per unit area, grain number per spike (spike number of glumes per spike), granulation rate and grain weight. The spike number per unit area consists of the number of plants, the number of tillers per plant and the tillering percentage, and the increase or decrease of the spike number has the greatest influence on the yield among four factors of the yield of rice. The key stage in determining the number of ears per unit area is at the tillering stage. Therefore, the method is a main attack target in the tillering stage by re-applying base fertilizer and early applying tillering promoting fertilizer on the basis of cultivating strong seedlings, promoting tillering to grow quickly, ensuring that the proper number of stem tillers is reached in the effective tillering stage, improving tillering quality and earning rate and finally reaching the proper number of ears.

Obviously, the reduction of nitrogen in rice seedling fertilizer and basal tiller fertilizer is not beneficial to cultivating strong seedlings with tillers, tillers are not beneficial to early growth and quick growth, early enough seedlings and tillering into ears, and the high and stable yield is not beneficial.

Disclosure of Invention

The purpose of the invention is as follows: in order to solve the problems in the prior art, the invention provides a breeding method for cultivating a japonica rice variety with high-efficiency utilization of nitrogen, so that the selection pressure of related characters is increased to improve genetic response, and the 'nitrogen-reducing and synergistic' japonica rice variety suitable for being planted in the middle and lower reaches of Yangtze river is cultivated.

The technical scheme is as follows: in order to achieve the purpose, the invention can adopt the following technical scheme:

a breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency comprises the following steps:

A) selection of parents and F₀Configuration: hybridizing by using early-growing and fast-growing panicle grain compatible japonica rice variety as female parent and using panicle grain compatible type japonica rice variety as male parent to obtain F₀；

B) F is to be₀Directly seeding in the middle and lower reaches of Yangtze river at the time of 5 months 15 days-5 months 20 days to obtain F₁(ii) a Randomly investigating the number of tillers of more than or equal to 30 seedlings 25-30 days after sowing, eliminating the combination with low average number of tillers of single plants, selecting and reserving excellent combination by applying a pedigree method during maturation, and mixing and reserving seeds to obtain F₂；

G) F is to be₂In Hainan Ling water, seeding in 12 months 25-12 months 30 days to ensure the seedling to be more than 2000, pulling out weak seedlings with few stem tillers of a single plant 25-30 days after seeding, selecting excellent individuals with a large spike number of the single plant during maturation, and harvesting and reserving seeds in a mixed manner to obtain F₃；

H) F is to be₃In the middle and lower reaches of Yangtze river, the seedlings are sowed in a sparse direct way in 6 months, 5 days to 6 months and 10 days, more than 2000 seedlings are ensured to be grown, weak seedlings with few stem tillers of a single plant are pulled out 25 to 30 days after sowing, excellent individuals with a large spike number of the single plant are selected and left in the mature period, and mixed harvest and seed reservation are carried out to obtain F₄；

I) F is to be₄Thinly sowing and raising seedlings in the Yannan Ling water at 25-12 months and 30 days, transplanting and planting, removing weak seedlings with few tillers of a single plant 25-30 days after sowing, transplanting the single plant, selecting and reserving a good single plant with a large number of spikes of the single plant during maturation, and harvesting and reserving seeds to obtain F₅；

J) From F₅Establishing strains, thinly sowing and raising seedlings in the middle and downstream areas of Yangtze river within the period of 5 months and 15 days to 5 months and 20 days, transplanting and planting, randomly investigating the number of tillers of more than or equal to 30 seedlings after sowing for 25-30 days, eliminating the strains with small average number of tillers of a single plant, transplanting the strains with large average number of tillers of a single plant, selecting excellent single plants with large spike number of the single plant during maturation, and collecting and reserving the seeds to obtain F₆；

G)F₆And if the later generations are still separated, continuing to select the best from the best according to the steps E) and F) until obtaining a stable strain and promoting the stable strain to participate in the middle test of each level.

Furthermore, in the step A), the female parent is a premature and fast-growing panicle grain compatible japonica rice variety, and specifically, the japonica rice variety is sown in the middle and downstream areas of Yangtze river within 5 months and 15 days and within 5 months and 20 days, the dosage of the nitrogen fertilizer for the seedling is 7-8kg, the transplanting is carried out on a single plant, the planting density is 13-14cm multiplied by 24-26cm, the dosage of the nitrogen fertilizer for the basal tiller is 14-15kg, the average tiller number of the single plant after planting is 20d is more than or equal to 8, the total glume flower amount per mu is more than or equal to 3000 ten thousand at maturity, the maturing rate is more than or equal to 90%, and the thousand seed weight is more than or equal to 25 g.

Furthermore, in the step A), the male parent is a panicle grain compatible japonica rice variety, and specifically, a variety which is suitable for planting in an ecological area, has a total glume flower amount per mu of more than or equal to 2800 ten thousand, a seed setting rate of more than or equal to 90 percent and a thousand-grain weight of more than or equal to 25g is selected.

Further, in step B), F₀The seeding quantity of the dilute direct seeding planting is 3-4 kg/mu; f₁Mixing the remaining seeds to obtain F₂The method specifically comprises the steps of reducing the nitrogen dosage of the seedling fertilizer by 40-50% in a same ratio to 3-4kg, randomly investigating the number of tillers of seedlings larger than or equal to 30 days after sowing for 25-30 days, eliminating the combination of which the average number of tillers of a single plant is smaller than or equal to 2, selecting and reserving an excellent combination by applying a pedigree method during maturation, and harvesting and reserving seeds in a mixed mode.

Further, in step C), F₂Planting in a direct seeding mode, and harvesting and reserving seeds in a mixed mode to obtain F₃The specific seeding rate is 3-4 kg/mu, the seed consumption is 60-70g, and the seeding area is 13-15m²Ensuring that more than 2000 plants are grown; 3-4kg of seedling fertilizer nitrogen consumption which is reduced by 40-50% in a same ratio, pulling out weak seedlings with the number of single plant tillers less than or equal to 2 after sowing for 25-30 days, managing the field with other direct seeding fields, selecting excellent individuals with the single plant spike number more than or equal to 5 when the seedlings are mature, and harvesting and reserving seeds in a mixed mode.

Further, in step D), F₃Planting in a direct seeding mode, and harvesting and reserving seeds in a mixed mode to obtain F₄The specific seeding rate is 3-4 kg/mu, the seed consumption is 60-70g, and the seeding area is 13-15m²Ensuring that more than 2000 plants are grown; 3-4kg of seedling fertilizer nitrogen which is reduced by 40-50% in terms of same ratio, pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 after sowing for 25-30d, selecting excellent individuals with the number of spikes of the single plant being more than or equal to 7 when the seedlings are mature, and harvesting and reserving seeds in a mixed mode.

Further, in step E), F₄Cultivating seedlings by sparse sowing, transplanting, specifically sowing the seedlings at 9-10 kg/mu, transplanting the seedlings at 60-70g, sowing the seedlings in 4-5m area²3-4kg of seedling fertilizer nitrogen which is reduced by 40-50% in terms of dosage by same ratio, pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 after sowing for 25-30d, transplanting the weak seedlings singly, 10-11kg of seedling fertilizer nitrogen which is reduced by 30-40% in terms of dosage by same ratio in a transplanting field, selecting good single plants with the number of grown single plants being more than or equal to 8 when the nitrogen dosage of the scion grains is the same as that of other transplanting fields, and harvesting and reserving the seeds singly.

Further, in step F), F₅Performing thin sowing and seedling raising in different branches, and transplanting and planting, wherein the sowing quantity is 9-10 kg/mu; reducing the nitrogen dosage of the seedling fertilizer by 40-50% in a same ratio to 3-4kg, randomly investigating the tiller number of more than or equal to 30 seedlings after sowing for 25-30 days, eliminating the strain line with the average tiller number of a single plant being less than or equal to 2, transplanting the strain line with the average tiller number of the single plant being more than or equal to 2, reducing the nitrogen dosage of the seedling fertilizer by 30-40% in a same ratio to 10-11kg, selecting and reserving excellent single plants with the spike number of more than or equal to 10 when the spike fertilizer nitrogen dosage is mature, and reserving seeds singly to obtain F₆。

Furthermore, the excellent single plants in the step G) are single plants with the average spike number of more than or equal to 8 in the southern Hainan Lingshui and the average spike number of more than or equal to 10 in the middle and lower reaches of Yangtze river.

Has the advantages that: the invention has the following advantages:

(1) culturing japonica rice varieties with high nitrogen utilization efficiency:

the method takes the early-growing and fast-growing panicle grain compatible japonica rice variety as a female parent and takes the panicle grain compatible japonica rice variety as a male parent for hybridization, reduces the nitrogen dosage in the seedling stage and the tillering stage, takes the single plant (average) tiller number and the single plant (average) spike forming number as selective pressures, and can greatly reduce the nitrogen input of seedling fertilizer and base fertilizer, realize early growth and fast-growing, early enough seedlings, ensure that the proper tiller number is reached in the effective tillering stage, improve the tillering quality and the spike forming rate, and finally realize the purposes of weight reduction, drug reduction, quality improvement and synergy in rice production.

(2) Improving the adaptability of japonica rice varieties:

the japonica rice variety bred by the breeding method can realize high and stable yield under the high fertility level, can also stably increase the yield under the medium and low fertility level, enhances the adaptability of the japonica rice variety, enlarges the planting area of the japonica rice variety and effectively improves the planting benefit of vast middle and low yield fields.

(3) Environmental protection and pollution reduction:

the japonica rice variety cultivated by the breeding method can greatly reduce the nitrogen consumption in the early stage of rice growth, improve the spike grain fertilizer ratio, realize the 'nitrogen reduction' and 'synergistic' of the rice in one life and reduce the non-point source pollution caused by nitrogen surplus and loss. In addition, the nitrogen dosage in the early stage is less, the leaf color is light, the tissues are old and spicy, the occurrence of diseases and pests is less, the harm is light, and the using times and dosage of pesticides are greatly reduced. The purposes of weight reduction and drug reduction are realized through nitrogen reduction, so that the pollution is reduced, and the environment is protected.

(4) Labor and cost are saved, and the rice planting benefit is improved:

the japonica rice variety cultivated by the breeding method realizes the 'weight reduction' and 'drug reduction' of the rice in the whole life, and reduces the investment of agricultural resources and labor cost.

Drawings

FIG. 1 is a schematic flow chart of a breeding method in example 1 of the present invention.

Detailed Description

Example 1:

referring to fig. 1, the invention discloses a breeding method for cultivating a japonica rice variety with high nitrogen utilization efficiency, comprising the following steps:

A) in the Yannan Ling water of 2012 winter, Zhenuo No. 19 of the early-growing and fast-growing panicle grain compatible japonica rice variety is taken as a female parent, and Wuyujing No. 27 of the panicle grain compatible japonica rice variety is taken as a male parent to be hybridized to obtain 104 seeds (F)₀)。

B) In 2013, 104 grains of F are collected in Jiangsu sentence Capacity in summer₀Directly sowing seeds at 5 months and 20 days to obtain F₁The nitrogen dosage of the seedling fertilizer is 3.5kg (40-50 percent of the same ratio), and the average tiller number of a single plant is 28 days after sowing>2.3, mixing and reserving seeds during maturation to obtain F₂。

C)2013, in winter, in Hainan Ling water, adding F₂In 12 months and 30 days, the seeds are sowed in a sparse way and usedThe seed quantity is 65g, the seeding area is 14m²3.5kg of nitrogen (40-50% of nitrogen is reduced at the same ratio), pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 at 28 days after sowing, selecting excellent individuals with the number of spikes of the single plant being more than or equal to 5 when the seedlings are mature, and mixing and reserving the seeds to obtain F₃。

D) In summer in Jiangsu sentence capacity in 2014, will F₃The seeds are sowed in a thin direct way at 5 days in 6 months, the seed consumption is 65g, and the sowing area is 14m²3.5kg of nitrogen (40-50% of nitrogen is reduced at the same ratio), pulling out weak seedlings with the number of tillers of a single plant being less than or equal to 2 at 28 days after sowing, selecting excellent individuals with the number of spikes of the single plant being more than or equal to 7 when the seedlings are mature, and mixing and reserving the seeds to obtain F₄

E) In 2014, in winter, in Hainan Ling water, F₄The seedlings are sowed at a low rate (the sowing quantity is 10 kg/mu) 30 days in 12 months, and the seedlings are transplanted, the seed consumption is 65g, and the sowing area is 4.5m²3.5kg of seedling fertilizer nitrogen (40-50% reduced by same ratio), pulling out weak seedlings with single plant stem tiller number less than or equal to 2 at 28d after sowing, transplanting the seedlings singly, 10.5kg of seedling fertilizer nitrogen (30-40% reduced by same ratio) at the basal stage of the transplanted field, selecting 20 excellent single plants with single plant spike number more than or equal to 10 in the same amount of spike grain fertilizer nitrogen as other transplanted fields during maturation, and harvesting and reserving seeds singly to obtain F₅。

F) In 2015, summer in Jiangsu sentence content, compare F₅Carrying out sparse sowing and seedling raising in 20 days at 5 months and 5 days, transplanting and planting, wherein the dosage of seedling nitrogen fertilizer is 3.5kg (40-50% reduction by year on year-on-year basis), the number of stem tillers of 30 seedlings is randomly investigated in each plant line after sowing for 28 days, 6 plant lines with the average number of stem tillers of a single plant being less than or equal to 2 are eliminated, the number of single plant lines with the average number of stem tillers of a single plant being transplanted is more than or equal to 2, the dosage of seedling nitrogen fertilizer in a transplanting field is 10.5kg (30-40% reduction by year on year-on-year basis), the dosage of spike nitrogen fertilizer is the same as that in other transplanting fields, 17 excellent single plants with the spike number being more than or equal to 10 are selected and reserved in a single harvest mode when the seedlings are mature, and F is obtained₆。

G) In 2015, in winter, in Hainan tomb water, F₆Carrying out sparse sowing and seedling raising in 30 days in 12 months, transplanting and planting, wherein the dosage of seedling fertilizer nitrogen is 3.5kg (40-50% reduced by year on year-on-year basis), the number of stem tillers of 30 seedlings is randomly investigated by each strain after sowing for 28 days, 7 strains with the average number of stem tillers of a single plant being less than or equal to 2 are eliminated, 10 strains with the average number of stem tillers of a single plant being more than or equal to 2 are transplanted, the dosage of fertilizer nitrogen of basal tillers of a transplanting field is 10.5kg (30-40% reduced by year on year-on-year basis), the dosage of spike fertilizer nitrogen is equal to that of other transplanting fields, 10 excellent single plants with the spike number being more than or equal to 10 are selected and reserved when the seedlings are mature,collecting seeds singly to obtain F₇。

H) In 2016 in summer, Jiangsu sentence Capacity, general formula F₇Carrying out sparse sowing in 20 days after 5 months and 20 days, transplanting and planting, wherein the using amount of seedling fertilizer nitrogen is 3.5kg (40-50% reduced by the same ratio), after sowing, each strain randomly investigates the number of stem tillers of 30 seedlings, 4 strains with the average number of stem tillers of a single plant being less than or equal to 2 are eliminated, the single strain with the average number of stem tillers of a single plant being more than or equal to 2 is transplanted, the using amount of the fertilizer nitrogen of a transplanting field base is 10.5kg (30-40% reduced by the same ratio), the using amount of spike grain fertilizer nitrogen is the same as that of other transplanting fields, 7 excellent single strains with the spike number being more than or equal to 10 are selected and reserved in a single harvest mode when the seedlings are mature, and F is obtained₈。

I)2016 in winter in Hainan Ling water, and adding F₈Carrying out sparse sowing and seedling raising in 30 days in 12 months, transplanting and planting, wherein the seedling nitrogen fertilizer consumption is 3.5kg (40-50% reduced by the same ratio), the number of stem tillers of 30 seedlings is randomly investigated in each plant line after sowing for 28 days, 2 plant lines with the average number of stem tillers of a single plant being less than or equal to 2 are eliminated, the plant line with the average number of stem tillers of the single plant being transplanted is more than or equal to 2, the nitrogen fertilizer consumption of basal tillers of a transplanting field is 10.5kg (30-40% reduced by the same ratio), the nitrogen fertilizer consumption of spike grains is the same as that of other transplanting fields, and 3 stable lines with the average spike forming number of the single plant being more than or equal to 8 are selected when the stable strains are mature.

The strain line with the code B9136 is neat in spike at 8 months and 30 days, the plant height is 100.7cm, the number of spikes of a single plant is 11.3, the total glume flower amount per mu is 3127.4 ten thousand, the maturing rate is 94.1%, the thousand-grain weight is 26.1g, the yield is increased by 5.9% compared with that of Wuyujing 23, the maturity is equivalent, the quality reaches the national standard high-quality second grade, and the strain line is tentatively named Zhendao 9136 and is prepared for expanding propagation and promoting to participate in the middle tests at all grades.