Using Molecular Marker-assisted To Breed Fine Rice Insect-resistant Maintainer Line Of Three Lines

Food production has been a big international issue, and as one of the main crop, rice has an important role to solve the food problem, but in the production of rice grain, the dangers of rice diseases and pests are very serious which lead to a decline in rice output and rice stem borer is one of them. But rice stem borer is one of the most important pests which harm a wide area of rice fields, the degree of harm is serious and period of time is long. Every year it to our country and even the world’s rice output loss is very serious. So borer hazard prevention is necessary and required. However, with the progress of the development on the level of science and technology, there have been all kinds of prevention and control rice stem borer measures. Chemical control is a common method in strategy, but the strategy of using chemical pesticide likely to cause pesticide residues in farmland and rice has significant potential harm to the ecological environment and human health. Therefore, cultivate and improve varieties of insect resistance is more environmentally friendly and economical choice.As we all know, the breeding of hybrid rice for rice grain production in China has made outstanding contributions.In the three-line hybrid breeding, the male sterile line (which is in fact the maintainer line) breeding is more important. Especially in the early Transgenic Bt Breeding research, we find the pure of Bt gene restorer line aggregate demand is very high when cultivate seed with the recovery lines of transgenic gene Bt. In the production practice, producing all containing the Bt gene hybridization production species is often difficult, this lack of resistance genes allows for the production of hybrid rice species of seed without resistance, and thus will not be able production applications.We use the CrylAb Transgenic Rice (recovery line MH86-CrylAb), bred the maintainer line(the male sterile line)with infertility gene and insect-resistant genes by means of a combination of marker-assisted selection and conventional breeding techniques(backcross breeding),the use of the linkage between molecular markers and the purpose of insect-resistant genes.G48B, Chuangu B, Xinhua B, G80B which breed by the unit are four potential maintainer lines with the characteristics of blast resistance. Using G48B, Chuangu B, Xinhua B, G80B respectively carried out reincarnation hybridization select with MH86-CrylAb restorer line, and get sterility maintainer line of three lines with anti-borers and disease resistance by the cycle of multi-generational. In addition, the corresponding male sterile line G48A, ChuanguA, Xinhua A, G80A and their hybrids as the female parent, the corresponding maintainer line G48B-CrylAb, ChuanguB-CrylAb, Xinhua B-CrylAb and G80B-CrylAb as paternal, through the cycle of multiple generations breeding and the Bt test strip to detect insect-resistant, obtain insect-resistant sterile line G48A-CrylAb, ChuanguA-Cry1Ab, Xinhua A-CrylAb and G80A-CrylAb.In this study, the achievements are as follows:1By restore line MH86-CrylAb carrying cycle of hybridization choice respectively with G48B, Chuangu B, Xinhua B, G80B and we rapidly detect insect resistance of their offspring by Jinbiao BT rapid detection test strip, select monoclonal which contains anti-borer gene according the field traits and insect resistance. In addition to the screening the SSR difference primers respectively between MH86-CrylAb and G48B, Chuangu B, Xinhua B, G80B.Use the above SSR primers to analyze the genetic background of the offspring, and make dendrogram based on the analysis of data as a field close criteria. We obtain excellent insect-resistant maintainer line G48B-CrylAb, ChuanguB-CrylAb, Xinhua B-CrylAb and G80B-CrylAb.2Using the male sterile line G48A, ChuanguA, Xinhua A, G80A and their hybrids as the female parent, the maintainer line G48B-CrylAb, ChuanguB-Cry1Ab, Xinhua B-CrylAb and G80B-CrylAb as paternal, carrying the cycle of multiple generations breeding, and field bagging verify its sterility of the selected male sterile line. So obtain insect-resistant sterile line G48A-CrylAb, ChuanguA-Cry1Ab, Xinhua A-CrylAb and G80A-CrylAb.3Verification of rice blast resistance gene:in order to verify the own resistance gene loss situation of the original maintainer line in the process of breeding, we do PCR by gene mapping marker, and then use enzyme digestion to detect it. The result indicates that rice blast resistance gene really exists in the selected plants.4Choose an ideal plant to give biology test about the insect resistance. In comparison with restorer Gangyou725, investigate plant height, effective panicle, seed setting rate and thousand seed weight, production plant, production, production (%) and other relevant agronomic traits about four hybrid combinations, so we verify the excellent traits of the maintainer line.In summary, the subject obtain excellent insect-resistant maintainer line G48B-CrylAb, ChuanguB-CrylAb, Xinhua B-CrylAb and G80B-Cry1Ab,The insect resistance male sterile line G48A-CrylAb, ChuanguA-Cry1Ab, Xinhua A-CrylAb and G80A-Cry1Ab.These studies has an important role in promoting the future rice breeding.