Abstract: The two major blast resistance genes,Pita and Pib,showed broad resistance spectrum to Magnaporthe grisea isolates in many rice planting areas of China and has been utilized in rice breeding and commercial production.However,the distribution of this two genes in present rice germplasms has not been well investigated,resulting in the blindness of their utilization in rice breeding.In the present study,the existence of the two genes in 115 landrace rice germlpasms and 19 rice leading cultivars were rapidly determined using the functional markers of Pita/pita and Pib/pib alleles.The results showed that 20 landrace accessions harbored Pita resistant allele and only 2 landrace accessions harbored Pib resistant allele.The Pita resistant allele distribute widely in china including Zhejiang Province,Fujian Province,Guangdong Province,Guangxi Province,Sichuan Province,Guizhou Province,Anhui Province,Jiangxi Province,Henan Province,Hebei Province,Jilin Province,but not found in Jiangsu Province,Shandong Province,Hunan Province,Hubei Province and Shanghai City.Only two landrace harbored the Pib resistant allele.However,11 cultivars harbored Pita resistant allele and 8 cultivars harbored Pib resistant allele.Interestingly,the 8 cultivars harboring Pib carried the Pita resistant allele simultaneously.These results are useful for rational utilization and deployment of the rice cultivars and germplasm with the Pita and Pib genes and for incorporating and stacking these genes into elite present leading cultivars and lines by marker assisted selection in rice breeding programs nationwide.

Key words: Rice, Rice blast, Leading cuhivar, Resistance gene, DNA marker

CLC Number: 

• Q78