Genetic analysis of interaction between rice and the blast pathogen in Thailand

摘要

One of the major constraints to Thai rice cultivation is blast disease, especially in aromatic rice Khao Dawk Mali 105, Rice is susceptible to blast disease at many growth stages. The genetic diversity of blast isolates was analyzed by DNA fingerprinting using a molecular technique, We collected samples and produced about 1,000 monospore isolates from rice cultivars, barley, and weeds, which covered rice fields in Thailand. We screened mating type and fertile isolates from testers with two fertile isolates from barley in the country and found mating types II and I from blast isolates. Barley isolates were clearly distinct from rice isolates using the AFLP technique. The occurrence of the opposite mating type is one reason for the high degree of genetic diversity of blast pathogen populations in Thailand. The DNA pattern of blast isolates was clustered in each group at 85% similarity. Some blast isolates represented each cluster group that was investigated for its virulence pattern on the rice differential host set, including Japanese differential cultivars, near-isogenic lines, some cultivars that carry known resistance genes, and traditional Thai cultivars. The pathotype test specifically aimed at detecting virulence gene characteristics that arelineage-specific. Based on data, the pathogen population in an area is expected to adapt to the host population. These cultivars should be used efficiently for suitable differential host set that involves interaction between the host and blast pathogenin Thailand. The data should be useful for developing rice cultivars with a more durable resistance to blast disease in Thailand.