Optimum screening time for improved WBPH-associated QTL analysis in rice

Whitebacked Planthopper is a sucking phloem sap insect which can greatly affect quality of the grain and yield losses. Determination of the resistance and susceptibility to WBPH is very important to accurate QTL analysis. The main objective of the study was to examine the level of resistance to determine optimum screening time using 120 doubled haploid lines. CNDH populations were developed from anther culture of F1, which was derived after a crossing WBPH, Sogatella furcifera resistance 'Cheongcheong' and susceptible 'Nagdong' lines. The genetic map with average 9.6 CM between markers was constructed from 120 CNDH populations, which included 217 SSR markers. Four QTLs were detected at different time and points based on the rate of seedling mortality after WBPH infestation. The markers were found to be comprehensive in identification of genotype and phenotype at coincident rate of 95% 14 days after infestation. These markers are efficiently very useful for MAS and develop new varieties in rice breeding program.