Simplified programmed rice breeding hybridization method

Abstract

The invention relates to the technical field of rice breeding, and discloses a simplified programmed rice breeding hybridization method which comprises a simplified hybridization technology, a hybrid progeny low-generation new group breeding treatment technology, a hybrid progeny middle-generation precise mature period determination technology and a hybrid progeny middle-generation seed fragrance determination technology. According to the method, during hybridization, the influence of factors such as space, equipment, electricity, environment and nature is avoided, rice hybridization is efficiently carried out under the condition that manpower, material resources and time are saved, low generations are not selected during hybrid offspring selection, and the method is suitable for large-scale popularization and application. Under the condition that a large amount of land, time, manpower and material resources are saved, too high and too late diseased plant seeds are removed, the target character proportion is increased, efficient generation adding seeds are achieved, and the method has the advantages of being high in practicability and saving time and labor.

Description

Technical Field

[0001] The invention relates to the technical field of rice breeding, and in particular to a simplified programmed rice breeding hybridization method. Background Art

[0002] Rice is one of the important food crops for mankind, and its history of cultivation and consumption is quite long. The current rice hybridization technologies are the pinching method for emasculating and the vacuum method for emasculating. The pinching method is to cut the lemma of the female rice ears suitable for hybridization, and use tweezers to pinch out the anthers in each lemma, while ensuring that the anthers are not damaged. It is time-consuming and labor-intensive, and there are many pseudo-hybrids; the vacuum method is to use a vacuum pump to emasculate the rice ears with the lemma cut open. The anthers can be cut, which is much more efficient than the pinching method. It requires a vacuum pump and is limited by space, so the efficiency is difficult to improve. It is relatively time-consuming and labor-intensive, and there are relatively many pseudo-hybrids.

[0003] In the processing of low-generation 1-6 generations of variety breeding, the pedigree method and group method are now mostly used. The pedigree method selects more and more, and is time-consuming, labor-intensive and land-consuming. When selecting individual plants in each generation, individual plants with strong hybrid vigor are mostly selected, which leads to slow stabilization and generally late selection of varieties. The group method uses hybrid combinations as units, without selection or selecting dominant plant groups. Although it saves time, labor and land, such groups have many poor plants, are generally late, and lose early-maturing and excellent plants.

[0004] The 7th generation of rice hybrid offspring is selected. The existing selection method is to select individual plants during the yellow maturity stage of rice. The maturity stage of the selected individual plants is not accurate, and the plant shape, panicle shape, and uniformity of the main tiller panicle all change, making it difficult to select accurately.

[0005] The selection of fragrant rice is currently commonly done by the pedigree method. Starting from the second generation of hybrid offspring, each generation is selected by picking grains and chewing raw rice grains in the field, which wastes a lot of time and manpower. In addition, lower generations are unstable, and the fragrant generation may not exist in the future.

[0006] During the rice breeding process, breeders often do the breeding themselves, and often hundreds of combinations are used to select a few varieties. There is no simple and efficient programmed breeding technology, which is costly, time-consuming and labor-intensive. The breeding process cannot be broken down and completed by different people. Therefore, it is necessary to design a simple and programmed rice breeding hybridization method that is practical, time-saving and labor-saving. Summary of the invention

[0007] The object of the present invention is to provide a simplified programmed rice breeding hybridization method to solve the problems raised in the above background technology.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a simplified programmed rice breeding hybridization method, including a simplified hybridization technology, a hybrid offspring low-generation new group breeding processing technology, a hybrid offspring middle-generation precise maturity period determination technology and a hybrid offspring middle-generation seed fragrance determination technology, including the following steps: S1; Planting bags: Plant the parents of the rice hybrid combination in the same rice bag, with one bag for each combination; S2: Leave the spikelets: After the parents have produced spikes, before 9:30 a.m. every day, select spikes of the mother parent with 30% flowering and 30% in the leaf sheath, cut off the spikes that have flowered on the upper part, and also cut off the spike spikes wrapped in the leaf sheath, leaving the middle spikelets. At this time, the anthers and stigmas in the spikelets are mature, and the spikelets are arranged and the excess spikelets are cut off; S3; Cut the lemma: Cut the lemma at the middle 1 / 2 of the lemma, perpendicular to the longitudinal axis of the lemma, cut horizontally to increase the area for pollination. The key is to ensure that all anthers are cut off without cutting the stigma. S4; Emasculation: After cutting off all the spikelets, use the three fingers of one hand to hold the base of the spike, and use the other hand to spray water. Move the three fingers upwards, and use the other hand to spray water until the top of the spike. Repeat the above steps to complete the emasculation. The pollen grains in the anther are round, and there are pores between the grains. When these pores meet water, they will actively absorb water, and the pollen grains will then absorb water and burst, making the pollen lose vitality, unable to germinate, and lose the ability to pollinate; S5; Bagging: Put the male ear and the female ear in the same bag, ensure that the flowering part of the male ear is higher than the female ear, make a record, knock the paper bag for pollination at noon for three consecutive days to complete the hybridization, remove the paper bag after 10 days and replace it with a plastic bag. S6: Harvest: 30 days after hybridization, the hybrid seed husk has been cut off by half, and the hybrid grains are exposed. The hybrid grains turn from green to white and then become transparent. At this time, they are harvested; S7; Breeding: New group breeding treatment technology is used for low-generation rice 1-6 generations through hybrid offspring; S8; Determination of maturity: Harvest the seventh generation of rice hybrid offspring plants that meet the breeding goals through the precise maturity determination technology of hybrid offspring generations; S9; Aroma measurement: The aroma of the 7th generation of seeds harvested after stabilization is measured by using the hybrid offspring mid-generation seed aroma determination technology; S10; Testing the varieties: determining the height, yield, rice appearance, 1000-grain weight, grain shape and aroma of the selected plants and deciding whether to keep or reject them; S11; Identification: Field identification, indoor fragrance determination and indoor seed testing are combined. The 7th generation of seeds are selected. The 8th generation is planted according to whether there is fragrance at maturity. Separated strains are eliminated. The maturity, yield, resistance, fragrance and rice appearance are identified. Rice tasting is performed on the strains that have fragrance and good appearance for two consecutive years. S12; Expansion propagation: Select seeds from the 8th generation and repeat the 8th generation for the 9th generation, increase the propagation amount and select seeds for preliminary testing.

[0009] According to the appeal plan, the new group breeding processing technology for low-generation hybrid offspring in step S7 is specifically as follows: the seeds obtained after rice hybridization are the first-generation hybrid seeds, and the subsequent seeds are the second and third generations, and so on. The new group breeding processing technology is used for low-generation rice 1-6 generations, and the dense planting density is 4.5*3 inches, the number of plants in a hole is 10-15, the total number of holes is more than 200 holes, and the total number of plants in each combination is more than 2000 plants. At this density, each seedling does not tiller, and various gene types are retained as much as possible. At the heading stage, a knife is used to remove unfavorable genotype ears such as too high ears and many awns. At the maturity stage, 1 / 3 of the ears are mature and they must be harvested. The harvested seeds are selected with 1.08 specific gravity salt water to remove late-maturing, diseased, and incompletely mature seeds for use next year. These 6 generations of seeds can be added in Hainan in winter, and 6 generations can be completed in three years.

[0010] According to the appeal plan, the precise maturity determination technology of the hybrid offspring in step S8 is as follows: the 7th generation of rice hybrid offspring is basically stable, individual plants are planted, and excellent individual plants are selected while determining the maturity period. In this pedigree, reference varieties of various maturity periods are planted, and marker rods of different colors are used to mark plant lines of different maturity periods. For example, local reference varieties Longdao 20, Changbai 9, Jiyujing, and Tong 35 are set for control. The heading periods are marked with purple rods for plants that head before July 21, yellow rods for plants that head from July 21 to 23, and The plants that produce ears from July 24 to 26 are marked with blue poles, and the plants that produce ears from July 27 to 29 are marked with red poles. When marking, the poles should be uniformly inserted in the same direction and close to the marked rice. At the same time, individual rice plants should be selected when inserting the poles. Individual plants with even main tillers and ears, suitable plant shape, no awns or few awns, grain size, length-to-width ratio, ear size, and stalk thickness should be selected. In autumn, only the plants with inserted poles are selected for harvest. When harvesting, the marked plants of different colors are harvested in advance according to the early or late maturity, and the plants that meet the breeding goals are harvested.

[0011] According to the appeal scheme, the technology for determining the aroma of seeds in the middle generations of hybrid offspring in step S9 is specifically as follows: after the 7th generation of hybrid offspring is stable, select excellent individual plants, grind the harvested seeds of the excellent individual plants into brown rice, put 4 grams of brown rice into a test tube, add 20 ml of 1.7% potassium hydroxide solution, plug the test tube with a cotton plug, soak it for 30 minutes, then smell its aroma, and distinguish the concentration of light aroma, fragrant aroma, and strong aroma.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) Hybridization is not affected by space, equipment, electricity, environment, nature and other factors, saving manpower, material resources and time, and allowing rice hybridization to be carried out efficiently.

[0013] (2) When selecting hybrid offspring, do not select the lower generations, saving a lot of land, time, manpower and material resources. Remove seeds that are too high, too late, and diseased, increase the proportion of target traits, and efficiently increase the generation of seeds.

[0014] (3) The 7th generation accurately determines the maturity period. It determines the maturity period at the heading stage, which is more efficient and accurate than determining the maturity period at the beginning of the harvest.

[0015] (4) The potassium hydroxide soaking method can be used to determine the aroma of rice in the laboratory, which saves time and is more accurate than in the field. It can also effectively distinguish the degree of aroma. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic diagram of the breeding of Tongyu 8603 of the present invention; DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0018] See also Figure 1 The present invention provides a technical solution: a simplified programmed rice breeding hybridization method, including a simplified hybridization technology, a hybrid offspring low-generation new group breeding processing technology, a hybrid offspring middle-generation precise maturity period determination technology, and a hybrid offspring middle-generation seed fragrance determination technology, including the following steps: S1; Planting bags: Plant the parents of the rice hybrid combination in the same rice bag, with one bag for each combination; S2: Leave the spikelets: After the parents have produced spikes, before 9:30 a.m. every day, select spikes of the mother parent with 30% flowering and 30% in the leaf sheath, cut off the spikes that have flowered on the upper part, and also cut off the spike spikes wrapped in the leaf sheath, leaving the middle spikelets. At this time, the anthers and stigmas in the spikelets are mature, and the spikelets are arranged and the excess spikelets are cut off; S3; Cut the lemma: Cut the lemma at the middle 1 / 2 of the lemma, perpendicular to the longitudinal axis of the lemma, cut horizontally to increase the area for pollination. The key is to ensure that all anthers are cut off without cutting the stigma. S4; Emasculation: After cutting off all the spikelets, use the three fingers of one hand to hold the base of the spike, and use the other hand to spray water. Move the three fingers upwards, and use the other hand to spray water until the top of the spike. Repeat the above steps to complete the emasculation. The pollen grains in the anther are round, and there are pores between the grains. When these pores meet water, they will actively absorb water, and the pollen grains will then absorb water and burst, making the pollen lose vitality, unable to germinate, and lose the ability to pollinate; S5; Bagging: Put the male ear and the female ear in the same bag, ensure that the flowering part of the male ear is higher than the female ear, make a record, knock the paper bag for pollination at noon for three consecutive days to complete the hybridization, remove the paper bag after 10 days and replace it with a plastic bag. S6: Harvest: 30 days after hybridization, the hybrid seed husk has been cut off by half, and the hybrid grains are exposed. The hybrid grains turn from green to white and then become transparent. At this time, they are harvested; S7; Breeding: New group breeding treatment technology is used for low-generation rice 1-6 generations through hybrid offspring; S8; Determination of maturity: Harvest the seventh generation of rice hybrid offspring plants that meet the breeding goals through the precise maturity determination technology of hybrid offspring generations; S9; Aroma measurement: The aroma of the 7th generation of seeds harvested after stabilization is measured by using the hybrid offspring mid-generation seed aroma determination technology; S10; Testing the varieties: determining the height, yield, rice appearance, 1000-grain weight, grain shape and aroma of the selected plants and deciding whether to keep or reject them; S11; Identification: Field identification, indoor fragrance determination and indoor seed testing are combined. The 7th generation of seeds are selected. The 8th generation is planted according to whether there is fragrance at maturity. Separated strains are eliminated. The maturity, yield, resistance, fragrance and rice appearance are identified. Rice tasting is performed on the strains that have fragrance and good appearance for two consecutive years. S12; Expansion propagation: Select seeds from the 8th generation and repeat the 8th generation for the 9th generation, increase the propagation amount and select seeds for preliminary testing.

[0019] Specifically, the new group breeding processing technology for low-generation hybrid offspring in step S7 is as follows: the seeds obtained after rice hybridization are the first-generation hybrid seeds, and the subsequent seeds are the second-generation and third-generation seeds, and so on. The new group breeding processing technology is used for low-generation rice generations 1-6, with a dense planting density of 4.5*3 inches, 10-15 plants in a hole, and a total number of holes exceeding 200 holes. The total number of plants in each combination exceeds 2000 plants. At this density, each seedling does not tiller, and various gene types are retained as much as possible. At the heading stage, a knife is used to remove unfavorable genotype ears such as over-tall ears and multi-awn ears. When 1 / 3 of the ears are mature at the maturity stage, they must be harvested. The harvested seeds are selected with 1.08 specific gravity salt water to remove late-maturing, diseased, and incompletely mature seeds for use next year. These 6 generations of seeds can be added in Hainan in winter, and 6 generations can be completed in three years.

[0020] Specifically, the precise maturity determination technology of the hybrid offspring in step S8 is as follows: the 7th generation of rice hybrid offspring is basically stable, individual plants are planted, and excellent individual plants are selected while determining the maturity period. In this pedigree, reference varieties of various maturity periods are planted, and marker rods of different colors are used to mark plant lines of different maturity periods. For example, local reference varieties Longdao 20, Changbai 9, Jiyujing, and Tong 35 are set for control. The heading periods are marked with purple rods for plants before July 21, yellow rods for plants from July 21 to 23, and yellow rods for plants from July 21 to 23. The plants that produce headings from July 24 to 26 are marked with blue poles, and the plants that produce headings from July 27 to 29 are marked with red poles. When marking, the poles should be uniformly inserted in the same direction and close to the marked rice. At the same time, individual rice plants should be selected when inserting the poles. Individual plants with even main tillers and ears, suitable plant shape, no awns or few awns, grain size, length-to-width ratio, ear size, and stalk thickness should be selected. In autumn, only the plants with inserted poles are selected for harvest. When harvesting, the marked plants of different colors are harvested in advance according to the early or late maturity, and the plants that meet the breeding goals are harvested.

[0021] Specifically, the technique for determining the aroma of seeds in the next generation of hybrid offspring in step S9 is as follows: after the seventh generation of hybrid offspring is stable, select excellent individual plants, grind the harvested seeds of the excellent individual plants into brown rice, put 4 grams of brown rice into a test tube, add 20 ml of 1.7% potassium hydroxide solution, plug the test tube with a cotton plug, soak for 30 minutes, smell the aroma, and distinguish the concentrations of light aroma, fragrant aroma, and strong aroma.

[0022] Working principle: The current rice hybridization technology is the clip removal method and vacuum removal method, which requires a vacuum pump. Due to equipment and space limitations, it is difficult to improve efficiency, it is relatively time-consuming and labor-intensive, and there are relatively many pseudo-hybrids. In view of these shortcomings, the hybrid male and female parents are planted in the same bag through the simplified hybridization technology, and the rice anthers are treated with water. The rice pollen grains burst after absorbing water, lose vitality and pollination ability, and achieve the effect of rice removal. At the same time, it is not limited by equipment and space, has fast speed, high efficiency, low self-pollination rate, and high fruit setting rate. Most people can do it, achieving the purpose of simplification; Taking the breeding of Tongyu 8603 as an example 1. The female parent Tongyu 269 and the male parent Tongyu Y1-40 were hybridized by simplified hybridization technology in 2017. They were sown on April 12 and transplanted into the same bag on May 20. When flowering, the female parent was cut and the anthers were cut from the middle of the glume. Water was sprayed on the anthers to make the pollen grains absorb water and burst, losing their activity. The parents were put together. When flowering at noon, the bag was shaken to pollinate the female parent and obtain hybrid F1 generation seeds. Second, the new group breeding technology of low-generation F1-F6 generations. F1-F6 generations are planted in Hainan in winter and locally in summer. The planting density in each area is 15*10CM, and multiple rice seedlings are planted. 2,000 plants are planted in each area. 1.08 salt water is used to select seeds before sowing each season. At the heading stage, the ears that are too high and have many awns are removed to increase the proportion of early-maturing plants and reduce the proportion of too high plants. No selection is made during harvesting, and the harvest group is harvested. Time, labor and land are saved in these 6 generations. 3. The maturity period of individual plants in the middle generation F7 was accurately determined. The F7 generation expanded the individual plant population to 500 plants. At the heading stage, the exact maturity period of individual plants was marked with stalks of different colors inserted into the ground, referring to the heading stage of the control variety. Individual plants that met the breeding goals were selected while marking. Fourth, the aroma of the seeds harvested from the middle generation F7 generation is determined. The seeds harvested from F7 are tested indoors. At the same time, the potassium hydroxide soaking method is used to determine the aroma of the offspring of the combination whose parents have aroma genes. Pour 4 grams of brown rice into a test tube, add 20 ml of 1.7% potassium hydroxide solution, plug it with a cotton plug, soak it for 20 minutes, and determine the light aroma, fragrant, and strong aroma by smelling it. Combined with the test data, retain the single plant whose appearance and rice quality meet the breeding goals; Fifth, the high-generation F8 generation distinguishes strains according to maturity and the presence or absence of fragrance, and identifies their yield, resistance, rice quality, taste, and fragrance; 6. Preliminary trials will be conducted on the high generation F9 lines that meet the breeding objectives.

[0023] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0024] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A simplified programmed rice breeding hybridization method, comprising a simplified hybridization technology, a new breeding processing technology for low-generation hybrid offspring, a technology for accurately determining the maturity period of the middle-generation hybrid offspring, and a technology for determining the aroma of seeds in the middle-generation hybrid offspring, characterized in that: The following steps are involved: S1; Planting bags: Plant the parents of the rice hybrid combination in the same rice bag, with one bag for each combination; S2: Leave the spikelets: After the parents have produced spikes, before 9:30 a.m. every day, select spikes of the mother parent with 30% flowering and 30% in the leaf sheath, cut off the spikes that have flowered on the upper part, and also cut off the spike spikes wrapped in the leaf sheath, leaving the middle spikelets. At this time, the anthers and stigmas in the spikelets are mature, and the spikelets are arranged and the excess spikelets are cut off; S3; Cut the lemma: Cut the lemma at the middle 1 / 2 of the lemma, perpendicular to the longitudinal axis of the lemma, and cut horizontally to increase the area for pollination. The key is to ensure that all anthers are cut off without cutting the stigma; S4; Emasculation: After cutting off all the spikelets, use the three fingers of one hand to hold the base of the spike, and use the other hand to spray water. Move the three fingers upwards, and use the other hand to spray water until the top of the spike. Repeat the above steps to complete the emasculation. The pollen grains in the anther are round, and there are pores between the grains. When these pores meet water, they will actively absorb water, and the pollen grains will then absorb water and burst, making the pollen lose vitality, unable to germinate, and lose the ability to pollinate; S5； Bagging: Put the male ear and the female ear in the same bag, make sure the flowering part of the male ear is higher than the female ear, keep a record, and knock on the paper bag for pollination at noon for three consecutive days to complete the hybridization. After 10 days, remove the paper bag and replace it with a plastic bag. S6: Harvest: 30 days after hybridization, the hybrid seed husk has been cut off by half, and the hybrid grains are exposed. The hybrid grains turn from green to white and then become transparent. At this time, they are harvested; S7； Breeding: New group breeding technology is used for low-generation rice from 1st to 6th generations through hybridization; S8; Determination of maturity: Harvest the seventh generation of rice hybrid offspring that meet the breeding goals through the precise maturity determination technology of hybrid offspring; S9; Aroma measurement: The aroma of the seeds harvested in the 7th generation after stabilization is measured by using the aroma determination technology of the seeds in the middle generation of hybrid offspring; S10; Testing the varieties: determining the height, yield, rice appearance, 1000-grain weight, grain shape and aroma of the selected plants and deciding whether to keep or reject them; S11； Identification: Field identification is combined with indoor fragrance determination and indoor seed testing. The 7th generation of seeds are selected, and the 8th generation is planted according to whether there is fragrance at maturity, and the separated strains are eliminated. The maturity, yield, resistance, fragrance, and rice appearance are identified. The rice is tasted for the strains that have fragrance and good appearance for two consecutive years; S12； Propagation expansion: Select seeds from the 8th generation and repeat the 8th generation for the 9th generation, increase the breeding amount and select seeds for preliminary testing.

2. The simplified programmed rice breeding hybridization method according to claim 1, characterized in that: The new group breeding treatment technology for low-generation hybrid offspring in step S7 is specifically as follows: the seeds obtained after rice hybridization are the first-generation hybrid seeds, and the subsequent seeds are the second-generation and third-generation seeds, and so on. The new group breeding treatment technology is used for low-generation rice generations 1-6, with a dense planting density of 4.5*3 inches, 10-15 plants in a hole, and a total number of holes exceeding 200 holes. The total number of plants in each combination exceeds 2000 plants. At this density, each seedling does not tiller, and various gene types are retained as much as possible. At the heading stage, a knife is used to remove unfavorable genotype ears such as over-high ears and multi-awn ears. When 1 / 3 of the ears are mature at the maturity stage, they must be harvested. The harvested seeds are selected with 1.08 specific gravity salt water to remove late-maturing, diseased, and incompletely mature seeds for use next year. These 6 generations of seeds can be added in Hainan in winter, and 6 generations can be completed in three years.

3. The simplified programmed rice breeding hybridization method according to claim 1, characterized in that: The precise maturity determination technology of the hybrid offspring in step S8 is as follows: the 7th generation of rice hybrid offspring is basically stable, individual plants are planted, and excellent individual plants are selected while the maturity is determined. In this pedigree, reference varieties of various maturity periods are planted, and marker rods of different colors are used to mark plant lines of different maturity periods. For example, local reference varieties Longdao 20, Changbai 9, Jiyujing, and Tong 35 are set for control. The heading periods are marked with purple rods for plants before July 21, yellow rods for plants between July 21 and 23, and yellow rods for plants before July 2. The plants that produce headings from April to 26 are marked with blue poles, and the plants that produce headings from July 27 to 29 are marked with red poles. When marking, the poles should be uniformly inserted in the same direction and close to the marked rice. At the same time, individual rice plants should be selected when inserting the poles. Individual plants with even main tillers and ears, suitable plant shape, no awns or few awns, grain size, length-to-width ratio, ear size, and stalk thickness should be selected. In autumn, only the plants with inserted poles are selected and harvested. When harvesting, the marked plants of different colors are harvested in advance according to the early or late maturity, and the plants that meet the breeding goals are harvested.

4. The simplified programmed rice breeding hybridization method according to claim 1, characterized in that: The technique for determining the aroma of seeds in the middle generations of hybrid offspring in step S9 is specifically as follows: after the seventh generation of hybrid offspring is stable, select excellent individual plants, grind the harvested seeds of the excellent individual plants into brown rice, put 4 grams of brown rice into a test tube, add 20 ml of 1.7% potassium hydroxide solution, plug the test tube with a cotton plug, soak for 30 minutes, smell the aroma, and distinguish the concentrations of light aroma, fragrant aroma, and strong aroma.

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