The Pi-ta gene also was found in rice cultivar known to contain the Pi-ta2 gene, although the allelic relationship of these genes remains to be determined. The presence of the Pi-ta gene in landrace cultivars in several different geographical locations, the Philippines and Vietnam, other indica rice cultivars in China and Colombia suggest that the Pi-ta gene may have spontaneously originated in indica rice cultivars. These results are useful for incorporating the Pi-ta gene into advanced breeding lines by markerassisted
selection for rice breeding programmes worldwide.