A kind of breeding method of all-fragrant soft rice two-line hybrid rice

Abstract

The invention discloses a breeding method of fully-aromatic soft rice two-line hybrid rice. The breeding method specifically comprises the following steps: screening out an aromatic soft rice variety I and an aromatic soft rice variety V which have different genetic backgrounds and genotype of aabb, respectively importing the gene a, controlling aroma, and a gene b, with low-grain amylose content, in the aromatic soft rice variety I and the aromatic soft rice variety V into two-line sterile line II and a restoring line IV, and crossing the high-quality fully-aromatic soft two-line hybrid rice VII with the genotype of aabb by taking the obtained aromatic soft rice two-line sterile line III as a female parent and the aromatic soft rice restoring line VI as a male parent. According to the bred fully-aromatic soft rice two-line hybrid rice VII, the yield is high, each rice grain has aroma, and the rice is soft and cannot cause retrogradation after being cooled.

Description

technical field [0001] The invention relates to a hybrid rice breeding technology, in particular to a method for breeding two-line hybrid rice of whole-fragrant soft rice. Background technique [0002] The successful invention and application of indica hybrid rice breeding methods in my country has created huge economic and social benefits. However, hybrid rice is a segregated F 2 Generation seeds, the quality traits are between the parents, the combination of high-quality preparation of both parents, especially the allelism of high-quality trait genes such as fragrance genes, can fundamentally prevent F 2 Genetic segregation of rice grains, so that the internal quality of rice grains does not separate or the separation is controlled to a minimum. Since the physical and chemical indicators of the high-quality two-line hybrid rice parents in my country are all above the national excellent grade 3, it is difficult to prepare more high-quality hybrid rice combinations. As a r...

AI Technical Summary

Problems solved by technology

However, there are some defects in these fragrant hybrid rice breeding methods: first, the quality of the paired parents is not good, such as high amylose content, not soft rice type, although the paired breeding can obtain full-fragrant hybrid rice varieties or natural ginseng type However, due to the high content of amylose, the rice will regenerate after cold, harden and taste bad; the second is to match the parents, that is, the quality of the sterile line and the restorer line are inconsistent, such as the content of amylose is inconsistent , leading to hybrid rice (F 2 Genetic segregation of the quality traits of the generation seeds) results in the formation of miscellaneous rice with different hardness and softness, which is poor in quality and not easy to cook; thirdly, although both parents of the mating group have fragrance, the genes that control the fragrance are often unequal, and the hybrid mating group The hybrid rice variety obtained may not be a full-flavored variety with insufficient fragrance

However, compared with hybrid rice varieties, due to the lack of richer genetic basis of hybrid rice, the recombination of more excellent genes, and the expansion of genetic differences, the yield of conventional rice is always more than 20% lower than that of hybrid rice, resulting in a decline in rice production. Indica hybrid rice has high yield but poor quality, while high-quality fragrant soft rice conventional rice has good quality but low yield, which cannot meet the market's increasing requirements for rice quality, let alone adapt to the national food security strategy and The Competitive Demands of the International Market

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