Evaluation of blast resistance spectrum and identification of resistance genes in 82 rice germplasm resources

To exploit blast resistance in rice germplasm resources, a total of 82 rice accessions were assessed for blast resistance spectrum and resistance genes distribution, using inoculation of blast isolates and screening of molecular markers tightly lined to nine major resistance genes. The results showed that 11 of 82 accessions (13.4%) had broad resistance spectrum and 55 of 82 accessions (67.1%) had medium resistance spectrum. The Pia, Pita-2/Pita, Pita, Piz, Piz-t and Pik-h genes were harbored in 78.0%, 76.8%, 54.9%, 50.0%, 39.0%and 35.4%of 82 rice accessions, respectively. The Pik and Pib genes were only harbored in three rice accessions respectively. No accession was found to contain Pik-m gene. Most of accessions contained 2-5 resistance genes. With the number of resistance genes increasing, the accession had strong resistance to rice blast.