Identification of quantitative trait loci associated with resistance to brown planthopper in the indica rice cultivar Col.5 Thailand

Abstract

The brown planthopper (BPH) is one of the most serious insect pests of rice throughout Asia. In this study, we constructed a linkage map to determine the locus for BPH resistance gene, using an F2 population from a cross between a resistant indica cultivar, 'Col.5 Thailand', and a susceptible cultivar '02428'. Insect resistance was evaluated using 147 F3 families and the genotype of each F2 plant was inferred from the phenotype of corresponding F3 families. Two QTLs was detected on chromosome 2 (explains 29.4% phenotypic variation) and 6 (46.2% variation explained) associated with resistance to BPH in the mapping population. Comparison of the chromosomal locations and reactions to BPH biotypes indicated that the gene on chromosome 6 is different from at least 18 of the 19 previously identified BPH resistance genes. These two genes have large effects on BPH resistance and may be a useful BPH resistance resource for rice breeding programs. © OIKOS.