Mapping And Near Isogenic Line Development Of Brown Planthopper Resistance Genes Derived From Guangxi Common Wild Rice (Oryza Rufipogon Griff.)

Rice (Oryza sativa L.) is the staple food for nearly two thirds of the population in our country, and the stability of its production is directly relevant with the food security. However, brown planthopper (Nilaparvata lugens Stal, BPH) is one of the most destructive pests for rice production. At present, exploring new BPH resistance genes from rice genetic resources and introgressing them into various varieties are the most effective measures to control the pests. In present study, high BPH resistance rice line W2183, was introgressed into Japonica rice lines, Nipponbare, Baimao and BaiR54, and Indica rice lines, Huanghuazhan and Kangwenqingzhan, and five mapping populations were constructed. The resistant segregation of the F2populations was screened with BPH insects and the data of phenotypes were analyzed by softwares JoinMap3.0and MapQTL5.0for achievement of BPH-resistance gene mapping results. The main founding of the research was as follows:1、One hundred and twenty and140plants of F2populations respectively from Huanghuazhan/05BPHR17and Kangwenqingzhan/05BPHR16were screened. Results showed that two genes in both05BPHR17and05BPHR16derived from wild rice resistant source W2183were responsible for the BPH resistance. Numbers of498and462pairs of SSR markers covering the whole genome of rice were chosen to locate the resistance gene. The results indicated that one resistance gene was located between RM16766and RM16858on the long arm of chromosome4and the other was between RM16465and RM16502on the short arm of the same chromosome in the05BPHR17. The fine mapping results of them in05BPHR16were showed that one on the long arm was further fine located between RM16853and RM16858with physical distance about191kb by referring genomic sequence of Nipponbare while the other on the short arm was between RM16465and RM6659about968kb region. The LOD for both genes is15.8and31.1, and it can explain40.5%and86.8%of the phenotypic variation.2、Three near-isogenic lines (NILs) under backgrounds of Baimao, BaiR54and Nipponbare were constructed. Using BC3F1individual plants for the test of five agronomic traits, plant height, panicle length, tiller number, effective panicle number and1000-grain weight were investigated. The results showed that plant height and panicle length between NILs under the three genetic backgrounds of their recurrent parents were no significantly different.3、Five pyramiding lines carrying3or4different BPH resistance genes were developed through backcross and marker-assisted selection.