Selection method of polymeric rice sheath blight resistance breeding material

Abstract

The invention discloses a selection method of an anti-rice sheath blight breeding material. Varieties applied in production are taken as recurrent parents, local varieties or other cultivated varieties are taken as donor parents, and one time of hybridization, two times of backcross and two times of selfing are carried out to obtain a mixed group. Rice husk field dissemination method combined with toothpick embedding method is adopted and artificial inoculation is carried out for three consecutive generation to select a plant with an obviously lower degree of rice sheath blight disease than that of recurrent parents from the mixed group. Rice sheath blight site is detected by chi-square test, BC2F6 good disease resistant plant is selected to carry out hybridization, and a disease resistant polymeric line is screened by molecular maker selection and artificial inoculation. According to the invention, QTL location of target traits and variety improvement can be effectively integrated, genetic background effects of anti-sheath blight QTL can be overcome by polymerizing a disease resistant selected introgression line with a similar genetic background and disease resistant level of the rice line is improved.

Description

technical field [0001] The invention belongs to the technical field of breeding of new varieties and materials of crops, and in particular relates to a breeding method of rice sheath blight-resistant breeding materials. Background technique [0002] Sheath blight caused by Rhizoctonia solani kuhn is one of the important fungal diseases of rice, and the yield loss is 10%-30%, and can reach more than 50% in severe cases. Extensive use of chemical agents to prevent and control diseases not only easily causes environmental pollution, but also increases the cost of prevention and control year by year due to the enhanced drug resistance of pathogenic bacteria. The use of biological antagonists to control rice sheath blight can make up for the shortage of chemical agents, but the control period and other issues still need to be further studied. Therefore, breeding and planting disease-resistant varieties is one of the most economical and effective methods to control rice sheath bli...

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Problems solved by technology

However, it is further shown that the effect of a single locus on resistance to sheath blight in rice is small and has a significant background dependence. Even under the same environmental conditions, most QTLs for sheath blight resistance expressed in a rice genetic background It is often not expressed in another genetic background (Xie Xuewen et al., 2008, Genetic background and environmental effects of rice sheath blight resistance QTL expression, Acta Crops Sinica, 34(11): 1885-1893), therefore, although researchers learned from different resistance Some QTLs have been identified in the diseased varieties, but because most of the gene / QTL mapping in the past is usually completely out of touch with the practice of genetic breeding, it is difficult to effectively improve the resistance of rice varieties to sheath blight by molecular marker-assisted selection technology; in addition, through The conventional strategy of crossing resistant lines with different genetic backgrounds is also difficult to obtain sheath blight-resistant aggregation lines with further improved disease resistance

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