theexistence of the Pi-tagene in 141 rice germplasm accessions was
rapidly determined using these markers, and the results were confirmed
by inoculating rice germplasm with an M. griseastrain containing
AVR-Pita. The Pi-tagene was found in accessions from several major
rice producing countries, including China, Colombia, Japan, Vietnam,
the Philippines, Iran and the United States. The usefulness of DNA
markers for rapid determination of the genotype of rice germplasm
was thus demonstrated. ThePi-tagene also was found in rice cultivar
known to contain the Pi-ta
2
gene, although the allelic relationship of
these genes remains to be determined. The presence of the Pi-tagene 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-tagene into advanced breeding lines by marker-assisted selection for rice breeding programmes worldwide