Breeding method of mixed-flavor hybrid rice variety

Abstract

The embodiment of the invention discloses a breeding method of a mixed aromatic hybrid rice variety. The method comprises the following steps: obtaining rice resources 1-2 with different fragrance characteristics and fragrance genotypes, and parents of a maintainer line and a restorer line; carrying out hybridization and backcross on the rice resource 1 and the maintainer line parent, and carrying out sterile line transformation to obtain a sterile line material; hybridizing and backcrossing the rice resource 2 and the restorer parent to obtain a restorer material; the sterile line material and the restorer line material are subjected to hybridization matching, and the mixed-flavor hybrid water variety is bred. By combining a biotechnology, an electronic nose technology and an artificial analysis method, the fragrance difference of the rice varieties is classified carefully. Aiming at rice resources with different fragrance characteristics and fragrance genotypes, the research respectively constructs corresponding sterile lines and restorer lines. By means of the prepared hybrid combination, fragrance enhancement is successfully achieved, and the fragrance of the rice is richer and thicker. The popularization and the application of the hybrid japonica rice are greatly promoted.

Description

Technical Field

[0001] The embodiment of the present invention relates to the technical field of rice breeding, and in particular to a method for breeding a hybrid rice variety with a good aroma. Background Art

[0002] Rice aroma is considered to be an excellent trait. Aromatic rice has a high application value in market promotion and is loved by most consumers. Existing studies believe that the production of aroma is related to the mutation of the Bahd2 gene. This gene produces a recessive allele that inactivates betaine aldehyde dehydrogenase, resulting in an increase in 2-AP precursor substances and the production of aroma. The aroma of aromatic rice can be divided into many types according to the odor emitted, such as popcorn type, jasmine type, violet type, lettuce type, pecan type, toast type, fragrant rice type, basmati type, etc. At present, conventional rice has a single aroma. When two aromatic rice materials containing Badh2-E2 and Badh2-E7 are hybridized by conventional methods, only new materials containing Badh2-E2 or Badh2-E7 can be separated from the offspring, and new materials containing Badh2-E2 and Badh2-E7 at the same time cannot be created. According to the characteristics of hybrid rice F1 grain progeny segregation, the sterile line and restorer line containing Badh2-E2 and Badh2-E7 respectively were hybridized to create a new hybrid rice variety with both fragrant and aromatic properties, which is of great significance to the promotion and cultivation of fragrant rice.

[0003] The aroma of hybrid rice comes from its parents. At present, hybrid aromatic rice varieties in my country mainly show a single aroma. There are no reports on the cultivation of rice varieties with mixed aromas, and the sterile lines and restorer lines have not been carefully classified during the breeding process to distinguish different aromas. Therefore, by introducing different aroma genes into the sterile lines and restorer lines, and based on the separation characteristics of the seeds produced by the F1 generation of hybrid rice, rice varieties with both aromas can be cultivated, thereby expanding the application field of aromatic rice.

[0004] Practice has fully verified that the yield advantage of hybrid rice is only one aspect of hybrid vigor. As a popular staple food, hybrid rice breeding with a combination of aroma will undoubtedly become an important trend in rice breeding in the future. Globally, the aroma of rice has been widely regarded as a key quality indicator. Aromatic rice not only has high nutritional value, but also has a unique taste. It is rich in various amino acids, alkaloids, and various minerals such as calcium, phosphorus, and iron. It also contains rich trace elements such as zinc and selenium. These characteristics make it an important basis for the promotion and development of health rice in the future. Traditional and conventional breeding techniques are limited to the cultivation of rice varieties with a single aroma. By applying biotechnology, electronic nose detection and artificial screening, we can successfully create hybrid rice parents with different aromas, and further cultivate rice varieties with different aroma characteristics to better meet the diversified needs of markets in different regions.

[0005] The rice in northern my country is mainly characterized by the popcorn aroma of varieties such as Daohuaxiang No. 2 (also known as Wuyoudao No. 4) and Songjingxiang No. 1. These varieties are of high quality, but there are problems such as high plants, easy lodging, and low yield. To solve the above problems, the application of hybrid rice has been proven to be an effective way. In view of the rich germplasm resources of fragrant rice in my country, by breeding sterile line materials with different fragrance characteristics and carefully selecting restorer lines with short stalks, large panicles and different fragrances for matching, it can not only significantly reduce plant height and increase yield, but also make the hybrid combination of grains contain two kinds of fragrance genes, showing rich and diverse fragrance characteristics, so as to better meet the needs of different consumer groups and further enhance the competitiveness of my country's fragrant rice in the international market. Summary of the invention

[0006] To this end, the present invention provides a method for breeding hybrid rice varieties with different aromas. According to the hybrid rice F1 grain separation characteristics, different aroma genes are introduced into the sterile line and the restorer line respectively, and a hybrid combination is prepared so that the hybrid combination has two different aromas.

[0007] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0008] A method for breeding a hybrid rice variety with a good aroma, the method comprising the following steps:

[0009] (1) obtaining rice resources 1-2 with different aroma characteristics and aroma genotypes, as well as maintainer line and restorer line parents;

[0010] (2) The rice resource 1 is hybridized and backcrossed with the maintainer parent, and then the sterile line is converted to obtain the sterile line material;

[0011] (3) The rice resource 2 was hybridized and backcrossed with the restorer parent to obtain the restorer material;

[0012] (4) Hybridize the sterile line materials and the restorer line materials to select hybrid water cultivars with both fragrance and aroma.

[0013] Furthermore, the step of obtaining rice resources with different aroma characteristics and aroma genotypes specifically includes:

[0014] Collect rice resources with different aroma types for BADH2 gene detection, and divide the rice resources into rice groups with different BADH2 genotypes according to the detection results;

[0015] The aroma of different rice groups is detected by electronic nose, and the aroma of rice is manually judged based on the differences in volatile substances, so that rice resources are divided into rice groups with different aromas;

[0016] Through comparison, rice resources with different aroma characteristics and aroma genotypes were obtained.

[0017] Furthermore, in step (2), hybridization is performed with the maintainer as the female parent and the rice resource 1 material as the male parent to obtain a combination F1 of the maintainer / resource 1, and then backcrossing is performed with the maintainer as the female parent and the combination F1 of the maintainer / resource 1 as the male parent to obtain F1 seeds of the maintainer / / maintainer / resource 1 material. The offspring materials of the maintainer / resource 1 and the offspring materials of the maintainer / / maintainer / resource 1 are continuously self-pollinated in Shenyang and Hainan to F5, and the F5 generation group materials that meet the breeding objectives are selected for fragrance gene and restorer gene detection, and single ears containing fragrance genes but not restorer genes, with high stigma exposure and good flowering time are selected from the offspring group for separate planting, and stable F6 generation materials are obtained. They are continuously backcrossed with similar sterile lines in a plant factory for 5 generations to BC5F1, and stable sterile line materials are obtained. The new sterile line meets the requirements of stability, consistency and specificity of the new variety.

[0018] Furthermore, in step (3), rice resource 2 is hybridized with restorer line material to obtain restorer line / resource 2 combination F1, which is then backcrossed with restorer line as female parent and restorer line / resource 2 combination F1 as male parent to obtain F1 seeds of restorer line / / restorer line / resource 2 material. The offspring materials of restorer line / resource 2 and restorer line / / restorer line / resource 2 are continuously self-pollinated in Shenyang and Hainan to F5, and the F5 generation population materials that meet the breeding objectives are selected for fragrance gene and restorer line gene detection. Among the offspring population, those containing fragrance gene and restorer gene, fast grain filling and large number of grains per ear are selected for ear planting, and the stable F6 materials are matched with 5-10 mature sterile lines. According to the hybrid vigor, rice quality, disease resistance and fragrance of the hybrid combination, the target restorer line is selected, and the new restorer line meets the stability, consistency and specificity requirements of the new variety.

[0019] Furthermore, in step (4), sterile lines and restorer lines containing different aroma genes and having different steaming aromas and different aroma substances detected by the electronic nose are selected for mating. After the hybrid combination is planted, the hybrid F1 meets the requirements of the regional test in terms of yield, disease resistance, quality, etc., and can participate in the regional test. After completing the experimental procedures, the F2 generation separation materials are tested, and the ratio of different aroma genes in the materials is approximately 1:1.

[0020] The embodiments of the present invention have the following advantages:

[0021] The present invention combines biotechnology, electronic nose technology and manual analysis methods to carefully classify the aroma differences of rice varieties. For rice resources with different aroma characteristics and aroma genotypes, this study constructs corresponding sterile lines and restorer lines. Through the prepared hybrid combination, the aroma is successfully enhanced, making the aroma of rice more intense and rich. It will greatly promote the promotion and application of hybrid japonica rice. DETAILED DESCRIPTION

[0022] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention provides a method for breeding a hybrid rice variety with a good aroma:

[0024] (1) Collect rice resources with different aroma types from home and abroad, test the aroma rice resources for Badh2-E2 and Badh2-E7, and divide the different resources into groups based on the test results.

[0025] (2) An electronic nose is used to detect the aroma of rice from different groups. The aroma of rice is manually judged based on the differences in volatile substances. The aromatic rice resources are further classified according to the different aromas and the different genes they carry.

[0026] (3) The resources with different aromas are hybridized and backcrossed with the local backbone hybrid rice maintainer and restorer parents, and suitable new rice materials are selected according to the selection objectives.

[0027] (4) For new rice materials suitable for selection according to the selection objectives, the analysis of steps 1 and 2 is carried out, and the restoration gene detection is carried out at the same time. The offspring materials are divided into restoration line and maintenance line groups, and the aroma genes and aroma characteristics of different materials are marked.

[0028] (5) The new materials of the maintenance line are converted into a sterile line, and the converted sterile line is paired with a restorer line containing different fragrance genes to create a new hybrid combination.

[0029] (6) The yield and disease resistance of the new hybrid combination meet the local seed certification standards. The separation ratio of the two aroma types in the F1 seeds of this combination is approximately 1:1, and each contains different aroma genes, combining the different aromas of the male and female parents.

[0030] Example 1

[0031] This embodiment provides a method for breeding a new hybrid rice variety with a good aroma:

[0032] (1) Different aromatic rice resources containing Badh2-E2 and Badh2-E7 were detected through biotechnology. The aroma of the rice resources was different after electronic nose and manual judgment.

[0033] (2) The rice resources Liaonong 21 and Shennong 9741 that meet the breeding objectives are collected and hybridized to obtain the F1 of Liaonong 21 / Shennong 9741. The F1 is hybridized with the local material Liao 105B containing Badh2-E7 and maintaining the popcorn-type aroma to obtain the F1 of Liaonong 21 / Shennong 9741 / / Liao 105B. Then Liao 105B is used as the female parent and the F1 of Liaonong 21 / Shennong 9741 / / Liao 105B is used as the male parent. The hybrid and backcross F1 were continuously passed through Shenyang and Hainan to F5, and molecular and restored gene detection were performed. The individual plants that met the requirements were selected for planting. Liao 99A was used as the female parent and the F6 generation stable material was used as the male parent for hybridization. After continuous backcrossing for 5 generations to BC5F1, Badh2-E7 and popcorn-type aroma sterile line Liao 228A were selected. The sterile line material met the requirements of stability, consistency and specificity, and passed the Liaoning Provincial Appraisal in 2023. The results of the fragrance type and genetic expression analysis of the sterile line Liao 228 are shown in Table 1 below.

[0034] Table 1

[0035] variety Fragrance Genes Restoration Gene Liao 228A Popcorn flavor Badh2-E7 Not detected

[0036] (3) The fragrant rice resource DG19 (Badh2-E2) containing Badh2-E2 and with a violet aroma was hybridized with the restorer material R157 to obtain the F1 of DG19 / R157, and then R157 was used as the female parent and the F1 of DG19 / R157 as the male parent for backcrossing. The hybridized and backcrossed F1 were continuously self-pollinated in Shenyang and Hainan to F5. The F5 generation population materials that met the breeding objectives were selected for aroma gene and restorer gene testing. Among the offspring populations, those containing the Badh2-E2 aroma gene and the restorer gene, with fast grain filling and a large number of grains per ear were selected for ear planting. The stable F6 materials were tested and matched with 5-10 mature sterile lines. According to the hybrid vigor, rice quality, disease resistance and aroma of the hybrid combination, the C18 strain was selected with good performance and named restorer line R18. The new restorer line meets the requirements of stability, consistency and specificity of the new variety.

[0037] The results of genetic expression analysis of restorer line R18 are shown in Table 2 below.

[0038] Table 2

[0039] variety Fragrance Carrying gene Restoration Gene R18 Violet Badh2-E2 Rf1b

[0040] (4) By mating Liao 228A and R18, the hybrid japonica rice combination Liao 228A / R18 was obtained. This combination had a strong yield advantage and excellent rice quality in the preliminary trial of the medium and late maturing group in Liaoning Province in 2023. In 2024, it entered the regional trial of the medium and late maturing group in Liaoning Province for one year. The F2 segregation population was tested and it was found that the ratio of Badh2-E2 and Badh2-E7 genes carried in the grains was approximately 1:1.

[0041] Liaoyou 818 participated in the preliminary trial of the medium and late-maturing group in Liaoning Province in 2023. The average yield reached 648.2 kg / mu, an increase of 8.1% over the control Liaojing No. 9. The growth period was 158 days, the plant height was 109.8 cm, the ear length was 17.3 cm, there were 17.7 ears per hole, 149.1 grains per ear, a fruit set rate of 88.8%, and a thousand-grain weight of 23.5 g. The rice quality reached the ministerial standard of Grade 1 (see Table 1 below), with a strong aroma. It has now entered the regional trial in Liaoning Province for one year.

[0042] Table 3 Analysis of Liaoyou 818 rice quality

[0043]

[0044] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for breeding a hybrid rice variety with a good aroma, characterized in that: The method comprises the following steps: (1) obtaining rice resources 1-2 with different aroma characteristics and aroma genotypes, as well as maintainer line and restorer line parents; (2) The rice resource 1 is hybridized and backcrossed with the maintainer parent, and then the sterile line is converted to obtain the sterile line material; (3) The rice resource 2 was hybridized and backcrossed with the restorer parent to obtain the restorer material; (4) Hybridize the sterile line materials and the restorer line materials to select hybrid water cultivars with both fragrance and aroma.

2. The method for breeding a hybrid rice variety with a good aroma according to claim 1, characterized in that: The obtaining of rice resources having different aroma characteristics and aroma genotypes specifically includes: Collect rice resources with different aroma types for BADH2 gene detection, and divide the rice resources into rice groups with different BADH2 genotypes according to the detection results; The aroma of different rice groups is detected by electronic nose, and the aroma of rice is manually judged based on the differences in volatile substances, so that rice resources are divided into rice groups with different aromas; Through comparison, rice resources with different aroma characteristics and aroma genotypes were obtained.

3. The method for breeding a hybrid rice variety with a good aroma according to claim 1, characterized in that: In step (2), hybridization is performed with the maintainer as the female parent and the rice resource 1 material as the male parent to obtain a combination F1 of the maintainer / resource 1, and then backcrossing is performed with the maintainer as the female parent and the combination F1 of the maintainer / resource 1 as the male parent to obtain F1 seeds of the maintainer / / maintainer / resource 1 material. The offspring materials of the maintainer / resource 1 and the offspring materials of the maintainer / / maintainer / resource 1 are continuously self-pollinated in Shenyang and Hainan to F5, and the F5 generation group materials that meet the breeding objectives are selected for fragrance gene and restorer gene detection, and single ears containing fragrance genes but not restorer genes, with high stigma exposure and good flowering time are selected from the offspring group for line planting, and stable F6 generation materials are obtained. They are continuously backcrossed with similar sterile lines in a plant factory for 5 generations to BC5F1 to obtain stable sterile line materials, and the new sterile lines meet the requirements of stability, consistency and specificity of new varieties.

4. The method for breeding a hybrid rice variety with a good aroma according to claim 1, characterized in that: In step (3), rice resource 2 is hybridized with restorer line material to obtain restorer line / resource 2 combination F1, and then backcrossing is performed with restorer line as female parent and restorer line / resource 2 combination F1 as male parent to obtain F1 seeds of restorer line / / restorer line / resource 2 material. The offspring materials of restorer line / resource 2 and restorer line / / restorer line / resource 2 are continuously self-pollinated and multiplied to F5 in Shenyang and Hainan. The F5 generation population materials that meet the breeding objectives are selected for fragrance gene and restorer line gene detection. Among the offspring population, those containing fragrance gene and restorer gene, fast grain filling and large number of grains per ear are selected for ear planting. The stable F6 materials are matched with 5-10 mature sterile lines. The target restorer line is selected according to the hybrid vigor, rice quality, disease resistance and fragrance of the hybrid combination. The new restorer line meets the requirements of stability, consistency and specificity of the new variety.

5. The method for breeding a hybrid rice variety with a good aroma according to claim 1, characterized in that: In step (4), sterile lines and restorer lines containing different aroma genes and having different cooking aromas and different aroma substances detected by the electronic nose are selected for mating. After the hybrid combination is planted, the hybrid F1 meets the requirements of the regional test in terms of yield, disease resistance, quality, etc., and can participate in the regional test. After completing the experimental procedures, the F2 generation separation materials are tested, and the ratio of different aroma genes in the materials is approximately 1:1.

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