Improving Blast And Bph Resistance Of Dual-purpose Genic Sterile Rice Using Molecular Marker-assisted Selection

Two-line hybrid rice is one of important approach to utilize heterosis in rice,which plays an important role in ensuring food security in China.To breed dual-purpose genic male sterile rice,which polymerized genes resistant to rice blast and brown planthopper(Bph),through molecular marker assisted selection(MAS)technology,has important significance to enhance rice yield stability and increase rice production efficiency and reduce environmental pollution.In this study,in order to bred dual-purpose male sterile rice with resistance to both of rice blast and Bph,several broad-spectrum blast resistance gene Pi9,Pi47,Pi48,Pi49 and Bph resistance gene Bph14 and Bph15 were introduced to C815 S and Chuang5 S,respectively,by using the MAS technology.The objective genes were pyramided by crossed with receptor parents and donor parents,continuous backcrossed to the receptor parents,and then self crossed,with the target gene identified by using MAS technology.The main traits,which include blast resistance,brown planthopper resistance,fertility,agronomic traits and outcrossing traits,of the new bred dual-purpose genic male sterile rice were identified and evaluated.The main results were as follows:1.The molecular marker assisted selection technology system,which for genotype identification of rice blast resistance gene Pi9,Pi47,Pi48,Pi49 and Bph resistance gene Bph14 and Bph15,was developed.Several homozygous lines,which polymerized 1~3 rice blast resistance genes and 2 BPH resistance gene.2.The results of rice blast resistance showed that the male sterile line C815 S and the Chuang5 S were susceptible or moderately resistant,while the improved lines reached the level of resistance.The results of Bph resistance identification showed that the C815 S and Chuang5 S were both high susceptible,while the improved lines showed resistance.3.The results of agronomic traits and outcrossing characteristics showed that most of the agronomic traits of the improved lines were similar to those of the receptor parent,with several traits were better than the latter.