Breeding method using tetraploid recombination inbred lines hybridized/doubled between rice indica japonica subspecies

Abstract

The invention discloses a breeding method using a tetraploid recombination inbred lines hybridized / doubled between rice indica japonica subspecies. The breeding method includes the steps that indica rice is hybridized with japonica rice; doubling is carried out to obtain a tetraploid; the tetraploid is inbred, and tetraploid with target traits is selected for recombinant inbred lines; and a diploid with target traits is obtained by means of chromosome set ploidy reduction, that is, a rice breeding material with the targeted traits. The sterility of indica japonica F1 hybrids is overcome, the high tolerance of the tetraploid to the instability of a chromosome set is used to take the tetraploid as a platform that can quickly induce a large number of genomic mutations, the tetraploid recombination inbred lines with chromosome set variation such as part of homologous chromosome fragment exchange in the chromosome set and diverse phenotypes are quickly obtained from inbred progeny, and a diploid restorer induced by the chromosome set ploidy reduction method can mostly inherit the phenotype and resistance characteristics of their parental tetraploid. The breeding method has important significance for rice breeding.

Description

technical field [0001] The invention relates to the fields of biotechnology and agriculture, in particular to a method for breeding by using a tetraploid recombined inbred line hybridized / doubled between rice indica and japonica subspecies. Background technique [0002] As one of the important staple crops, rice feeds more than half of the world's population, and its yield and quality are crucial to maintaining global food security. In order to obtain rice varieties with high yield, strong stress resistance, high rice quality and good taste, breeders use various rice breeding methods to cultivate new rice varieties and expand rice germplasm resources. Existing rice breeding methods include crossbreeding, mutation breeding, spaceflight breeding and transgenic breeding, etc. Each of the above rice breeding methods has achieved great success, but each has certain limitations, as follows: [0003] Hybrid breeding: refers to the hybridization of two designated rice varieties and...

AI Technical Summary

Problems solved by technology

Its limitations include: a. There are limitations to the selection of hybrid parents. It is necessary to select two suitable rice varieties (usually it is necessary to select varieties with broad affinity or close relationship) as parents for hybridization, so as to avoid F1 generation hybrids. Sterility; b, rice heterosis does not appear in all hybrid combinations (many rice varieties show heterosis after hybridization), so the success rate of obtaining rice varieties with super-parent characteristics through cross-breeding is not 100%; c, breeding It takes a long time. For diploid rice, F1 hybrids need at least 7 generations of selfing to obtain hybrid offspring with non-segregated traits and homozygous loci

Its limitations include: a. There are few beneficial mutations induced by chemical reagents or physical rays, and a large number of rice seeds need to be used for treatment; b. The direction and nature of the mutagenesis cannot be controlled, and the success rate is low; c. The effect of improving quantitative traits is poor, Usually causes single-base mutations in the genome (point mutations), with minor effects on quantitative traits

Its limitations include: a, since the rice gene editing technology involves the process of callus induction and regeneration, it is only applicable to some rice varieties that can successfully induce callus and regeneration; b, for the target trait, it is necessary to grasp its genetic basis (For example, it is necessary to understand the genes that control it), and it is difficult to improve traits with unclear genetic basis; c, transgenic / gene-edited crops are strictly controlled in China, and there is still a long way to go before actual production and application

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