Genetics of Resistance to Green Rice Leafhopper in Rice: Mapping, Cloning and Development of Nearly Isogenic Lines

Abstract

Green rice leafhopper (GRH), Nephotettix cincticeps Uhler, is a serious insect pest of rice in East Asia. We have mapped six GRH resistance genes and several QTLs on rice chromosomes using DNA markers. However, the mechanism of the resistance is still unknown. An Indica variety DV85 having Grh2 (chromosome 11) and Grh4 (chromosome 3) showed high resistance to GRH, while an Indica variety Kasalath having Grh2 shows moderate resistance to GRH. Nearly isogenic lines (NILs) each carrying Grh2, Grh4 and both of the resistance genes derived from DV85 also demonstrated the complementary effects of both of Grh2 and Grh4. In the present study, we report molecular basis of Grh2 derived from the GRH resistant varieties. In addition, we will discuss about utilization of NILs for understanding GRH resistance.