Tagging Xa-1, the Bacterial Blight Resistance Gene in Rice, by Using RAPD Markers

Abstract

For identification of random amplified polymorphic DNA (RAPD) markers tightly linked to Xa-1, which is one of the bacterial blight resistance genes in rice, a near-isogenic line (NlL) for Xa-1 and a recurrent cultivar were screened by RAPD primers. Two out of 280 primers produced DNA fragments tightly linked to Xa-1, namely U087₇80and Y03₇00. No recombinant was detected between Xa-1 and Y03₇00, indicating that this RAPD fragment was closely linked to Xa-1. Y037₀0 existed in IR-BB I and Kogyoku as a single copy sequence, but did not exist in IR 24. U08₇50 was linked to Xa I at a drstance of 1 4 ±1.4 cM. These RAPD markers will facilitate selection of Xa-1 for breeding and will be starting points of gene cloning based on chromosome walking in near future.