Pyramiding The Rice Blast Resistance Gene Pi9 And The Brown Planthopper Resistance Genes Bph20(t)、ph21(t) To Breed The Male Sterile Lines

Rice is one of the staple food crops in the world, which occupies an important place in the global food production. China is the world’s top producer and consumer of rice, there are more than thirty million hectares cultivated land be used to grow rice. More than half the people in china take it as their staple diet. However, under the influence of a variety of plant diseases and insect pests, the rice yield descended. Especially the damage from rice blast and brown planthopper is very serious, which have threatened the safety of grain production of the world. According to the production practice, breeding new varieties of which resistant to rice blast and brown planthopper is a cost-effective and long-lasting way by using the known rice blast resistance genes and the known brown planthopper resistance genes.The study was conducted in two stages:In the first stage, using BoⅢB which is a maintainer line with perfect agronomic traits as receptor, and using 681 which is a rice varieties with the rice blast resistance gene Pi9 and BPH54 which is a rice varieties with brown planthopper resistance genes bph20(t)、bph21(t) as donor, the crossing and multiple generation backcrossing were been done. By using conventional breeding、the identification of brown planthopper resistance and molecular marker assisted selection,we can pyramid the genes Pi9、bph20(t) and bph21(t) in the rice maintainer line BoⅢB. Through backcross we can get the new rice maintainer line which resistant to rice blast and brown planthopper.In the second stage, using the rice breeding material with gene Pi9、bph20(t) and bph21(t) as donor, and using BoⅢA which is a male sterile line as receptor, the crossing and multiple generation backcrossing were been done. By using conventional breeding、molecular marker assisted selection、the test of pollen fertility and the identification of brown planthopper resistance, we can get the rice male sterile line which resistant to rice blast and brown planthopper.The results are as follows:1. The rice maintainer line intermediate material with rice blast resistance gene Pi9 and brown planthopper resistance genes bph20(t)、bph21(t) is available and its phenotype is extremely similar to BoⅢB.2. The rice male sterile line intermediate material with rice blast resistance gene Pi9 and brown planthopper resistance genes bph20(t)、bph21(t) is available.3. There are two pairs of primer which has polymorphism in the breeding parents. Further verify whether they are close linked to gene bph20(t), and decide if they can be used as the molecular marker of gene bph20(t).