A high-resolution map of the rice blast resistance gene Pi15 constructed by sequence-ready markers

The gene Pi15 for resistance of rice to Magnaporthe grisea was previously mapped to a approximate to 0.7-cM region on chromosome 9. To further define the chromosomal region of the Pi15 locus, a contig spanning the locus was constructed, in silico, through bioinformatics analysis using a reference sequence of the cultivar 'Nipponbare'. One simple sequence repeat marker adopted from the International Rice Microsatellite Initiative and six candidate resistance gene (CRG) markers, developed from gene annotation of the reference sequence of the contig, were used for linkage analysis in a mapping population consisting of 504 extremely susceptible F-2 plants. The Pi15 locus was delimited to a approximate to 0.5-cM region flanked by the markers CRG5 and CRG2 and co-segregated with the markers BAPi15(782), CRG3 and CRG4, which was physically converted to a 44-kb interval.