The Evaluation and Utilization of New Genes for Brown Planthopper Resistance in Common Wild Rice (<i>Oryza rufipogon</i> Griff.)

Abstract

Brown planthopper (BPH, Nilaparvata lugens Stal) is one of the most serious rice insect pests in Chinaand the world. Exploiting new resistance genes and breeding advanced genetic stocks are important for breeding resistance varieties. In this study, more than 1 200 accessions of common wild rice ( Oryza rufipogon Griff.), were evaluated for the resistance to several biotypes of BPH. 30 resistant accessions were obtained and 6 of them showed broad spectrum resistance to 5 or all of the 6 BPH biotypes, i.e. biotypes 1 and 2, Bangladesh, Mekong (Vietnam), Cuulong (Vietnam) and Pantnagar (India), which are spreading most rice growing regions in the world. Genetic analysis was turned out that the BPH resistance in these stocks was controlled by two pairs of recessive genes with duplicate interaction against biotypes 2 and Cuulong, but the resistance to the biotype Pantnagar was controlled by one pair of recessive gene. This indicated different genetic mechanism of reaction against BPH biotypesin the resistant sources. The two recessive genes existing in the entry 2183 might be new discovered genes as no BPH resistance gene has been reported in these chromosome regions. They were tentatively designated asbph18 (t) and bph19 (t), respectively. A total of 143 entries of advanced genetic stocks resistant to BPH and 6promising resistance lines or hybrid combinations with high yield or good quality were bred. These resistant advanced genetic stocks set a solid foundation for breeding new resistance varieties.