Identification of quantitative trait loci for resistance to whitebacked planthopper, Sogatella furcifera, from an interspecific cross Oryza sativa × O. rufipogon

Abstract

Quantitative trait loci (QTLs) for resistance to whitebacked planthopper (WBPH), Sogatella furcifera, were determined using 202 backcrossed inbred lines derived from a cross between the recurrent parent Xieqingzao B and an accession of Oryza rufipogon, and then tested using chromosome segment substitution lines (CSSLs) selected from BC3F3 populations of the same cross. Seedling mortality with WBPH infestation was measured to evaluate the resistance. Three QTLs were detected and the wild alleles always had the effect for decreasing seedling mortality. There were qWph2 located in the interval RM1285-RM555 on the short arm of chromosome 2, qWph5 in RM3870-RZ70 on the long arm of chromosomes 5, and qWph9 in RG451-RM245 on the long arm of chromosomes 9, among which qWph9 had the most stable effect. Duplicate lines of seven CSSLs carrying homozygous alleles of O. rufipogon at qWph9 were tested with WBPH infestation. Significant effects at P = 0.01 were observed for all the 14 lines. On the average, the seedling mortality was decreased by 55.2%. Validation of the major effect of qWph9 on enhancing WBPH resistance not only provides a useful QTL but also a series of breeding materials for rice improvement.