부산대학교 도서관

Bipolaris oryzae and B. zizaniae are the pathogens to cause brown spot on rice (Oryza sativa) and water bamboo (Zizania latifolia). Previous studies indicated that B. oryzae could be distinguished from B. zizaniae based on the hilum structure of conidia basal part. To understand the relationship of Bipolaris spp. causing brown spot on water bamboo and rice, the morphology, cross fertility, pathogenicity and molecular characters of Bipolaris spp. were analyzed. The observation of conidia indicated that the Bipolaris spp. isolates from rice and water bamboo showed similar morphology and rectangular hilum was the major type. The cross fertility test confirmed that the isolates from rice or water bamboo could mate successfully under light condition and produce ascospores. The pathogenicity test demonstrated that the isolates from rice or water bamboo could infect both with typical brown spot. Molecular phylogenetic analyses showed that Bipolaris isolates from rice or water bamboo formed a molecular group based on ITS (internal transcribed spacer) region. The other side, the analysis of GPDH (glycerol-3-phosphate dehydrogenase) sequence showed that isolates from rice could be separated into two molecular groups and one group isolates formed the same molecular group with isolates from water bamboo. Phylogenic analyses demonstrated that the Bipolaris spp. from rice or water bamboo were closely related to B. oryzae from GenBank. Our results suggest that the Bipolaris spp. from rice and water bamboo are same species of B. oryzae.