Author
WANG, ZHONGHUA - ZHEJIAN WANLI UNIV., PRC | |
Jia, Yulin | |
Rutger, J | |
XIA, YINGWU - ZHEJIANG UNIV., PRC |
Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/1/2006 Publication Date: 1/12/2007 Citation: Wang, Z., Jia, Y., Rutger, J.N., Xia, Y. 2007. Rapid survey for presence of a blast resistance gene Pi-ta in rice cultivars using the dominant DNA markers derived from portions of the Pi-ta gene. Plant Breeding. 126:36-42. Interpretive Summary: Molecular marker aided selection provides a novel opportunity to increase the speed of cultivar improvement through classical plant breeding. The Pi-ta gene in rice confers resistance to strains of the blast fungus,Magnaporthe grisea (Herbert) Borr. (anamorph Pyricularia oryza Cav.) which contain the corresponding avirulence gene AVR-Pita in a gene-for-gene fashion. The Pi-ta gene is a typical resistance gene producing protein with features of a nucleotide-binding site and leucine rich repeats. Nucleotide sequences distinguishing the resistant Pi-ta and susceptible pi-ta gene forms were previously identified and used for developing DNA markers for a resistant Pi-ta haplotype and three susceptible pi-ta haplotypes. In the present study, the existence of the Pi-ta gene in 142 rice accessions was rapidly determined using these markers, and the results were also examined by inoculating rice accesions with a M. grisea strain containing AVR-Pita. The Pi-ta gene was found in accessions from several major rice producing countries, including China, Colombia, Japan, Vietnam, Philippine, Thailand and the United States. The usefulness of DNA markers for rapid determination of the genotype of rice germplasm was thus demonstrated. The Pi-ta gene also was found in Pi-ta2 containing rice cultivars. The presence of the Pi-ta gene in landrace cultivars in several different geographic locations including the Philippines and Vietnam, and other indica rice cultivars in China, Colombia, and Thailand suggest that the Pi-ta gene may originate spontaneously in indica rice cultivars. These results are useful for incorporating the Pi-ta gene into advanced breeding lines by marker-assisted selection for rice breeding programs worldwide. Technical Abstract: The Pi-ta gene in rice confers resistance to strains of the blast pathogen Magnaporthe grisea (Herbert) Borr. (anamorph Pyricularia oryza Cav.) containing the corresponding avirulence gene AVR-Pita in a gene-for-gene fashion. The Pi-ta gene is a typical nucleotide-binding site type resistance gene. Nucleotide sequences distinguishing the resistant Pi-ta and susceptible pi-ta alleles were previously identified and used for developing DNA markers for a resistant Pi-ta haplotype and three susceptible pi-ta haplotypes. In the present study, the existence of the Pi-ta gene in 139 rice germplasm accessions was rapidly determined using these markers, and the results were confirmed by inoculating rice germplasm with a M. grisea strain containing AVR-Pita. The Pi-ta gene 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. The Pi-ta gene also was found in rice cultivar known to contain the Pi-ta2gene although allelic relationship of these genes remains to be determined. The presence of the Pi-ta gene in landrace cultivars in several different geographic 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 marker-assisted selection for rice breeding programs worldwide. |