抄録
The genus Rhizoctonia is one of the most important pathogens and causes serious damage to several crops. A significant amount of rice yield is reduced in most rice growing countries, including those in Asia, Europe, America, and Africa. A considerable number of researchers have studied this topic not only in Japan, but also in the other rice growing countries. However, research activity of the Genus Rhizoctonia is still at the initiation level, and very little information concerning the fungus is available in Myanmar. Therefore, the present study aims to give a preliminary report on the population structures of the Rhizoctonia species that infects rice sheaths in Myanmar. Diseased samples of rice sheaths were collected from April to June of 2007 in the summer rice growing season from the three rice growing areas of Myanmar, namely Mandalay, Pyinmana and Hmawbe. Isolation was conducted by a Water Agar (WA) medium at 25°C for 7 days. A total of 167 isolates were obtained from the diseased rice sheath symptoms; 44 isolates of the R. solani AG-1 IA, 30 isolates of the R. oryzae, and 93 isolates of the R. oryzae-sativae were collected. Preservation of these isolates was conducted on potato dextrose agar (PDA) slant media in test tubes. The cultured tubes were kept at room temperature, and were refreshed every 6 months.
