Molecular breeding method for improving stigma exsertion rate of sterile line of three-line rice

Abstract

The invention discloses a molecular breeding method for improving the stigma exsertion rate of a sterile line of three-line rice. The method comprises the following steps: with the low-stigma-exsertion-rate maintainer line of three-line rice as a recurrent parent and the maintainer line, carrying the stigma exsertion rate gene qES7, of three-line rice as a donor, performing hybridization and backcrossing; performing selection assisted by molecular markers closely linked with the stigma exsertion rate gene qES to obtain individual homozygous genotype plants with significantly improved stigma exsertion rate; and subjecting the individual homozygous genotype plants to hybridization with a wild-abortive cytoplasmic male-sterile line for 3 generations continuously so as to breed the improved sterile line with an increased stigma exsertion rate and paired maintainer lines. With the method, QTL for controlling the stigma exsertion rate can be quickly introduced, selection efficiency is improved, and help is provided for improving the stigma exsertion rate of the sterile line of hybrid rice and the yield of seed production.

Description

technical field [0001] The invention relates to the field of rice molecular breeding, in particular to a molecular breeding method for improving the stigma exposure rate of a three-line sterile line of rice. Background technique [0002] Rice is the most important food crop in my country, and the abundance or shortage of rice production will directly affect food security and social stability. The successful research of hybrid rice in the mid-1970s has greatly increased the yield of rice in my country. However, the current three-line and two-line breeding systems have low hybrid seed production and high seed production costs due to poor outcrossing performance of sterile lines. Greatly limited the large-scale promotion of rice production. Rice is a self-pollinated crop, and the structure of flower organ is suitable for self-crossing but not for out-crossing, which is one of the limiting factors for hybrid rice breeding and seed production. The rice stigma is the organ that r...

AI Technical Summary

Problems solved by technology

The successful research of hybrid rice in the mid-1970s has greatly increased the yield of rice in my country. However, the current three-line and two-line breeding systems have low hybrid seed production and high seed production costs due to poor outcrossing performance of sterile lines. Greatly limited the large-scale promotion of rice production

Although different scholars have conducted QTL analysis on the stigma exposure rate, the results of their respective studies are not completely consistent, which is related to the differences in the population properties, population size, analysis methods, number of markers, and density used in different studies. The complexity of QTL inheritance for exposed traits

At present, there are few reports on the fine mapping of QTL for rice stigma exposure rate, no QTL has been cloned so far, and no analysis of gene function and expression regulation has been carried out

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