Microscopic observation on mycorrhiza of Doritis pulcherrima
野生五唇兰菌根显微结构观察

Based on morphological characteristics and sequence alignment analysis of rDNA ITS region, 16 strains isolated from diseased plants of Setaria viridis from Beijing, Hebei and Henan, two strains isolated from diseased plants of Chloris virgata and Eleusine indica from Henan, and one strain isolated from diseased plant of Avena fatua from Qinghai, were identified as Bipolaris setariae. Artificial inoculation tests indicated that the strains from S. viridis had stronger pathogenicity than those from other hosts to S. viridis. The strain from A. fatua had no pathogenicity to S. viridis. The strains with different origins showed difference in virulence to S. viridis. The strain NY1 was strongly pathogenic to S. viridis. All the leaves blighted in 5 days after inoculation, and the whole plants died in 7 days. NY1 was also strongly pathogenic to the weeds C. virgata and Digitaria sanguinalis but had light or no pathogenicity to most crops. The B. setariae NY1 strain is potential to be developed as a microbial herbicide to the weeds S. viridis, C. virgata and D. sanguinalis.