Identification of SSR Markers Linked to a Bacterial Blight Resistance Gene in Rice Cultivar ‘Pin Kaset’

Abstract

Pin Kaset (PK), a Thai rice cultivar, has a high level of resistance to bacterial blight (BB) caused by Xanthomonas oryzae pv oryzae (Xoo) isolates. In this study, we identified the BB resistant gene in Pin Kaset (PK) using 436 BC2F2 plants from a cross between Ba7 and PK. The BC2F2 individuals were evaluated with a Xoo isolate TB0304. Based on the phenotypic and genotypic analysis, the SSR marker RM224 showed clearly discriminate banding pattern between resistant and susceptible phenotypes. The result revealed that the BB resistance gene was linked to RM224 on rice chromosome 11. This new gene was tentatively named as Xa34(t). Although this identified gene and other BB resistance genes were located in the same region and shared common linked markers on chromosome 11, no evidence has yet been obtained whether they share the same genomic sequence or whether they are tightly linked to each other.