The isolation and biological features of two albinotic isolates of Ustilaginoidea virens
稻曲病两个白化菌株的分离与生物学特性

Two isolates of Ustilaginoidea virens with natural marker, ZJa0201 and SXa0101, were obtained from albinotic false smut balls of rice. The albinotic isolates grew rapidly and reached about 3 times the growth speed of wild isolates in potato sucrose agar (PSA) medium, and no chlamydospore was detected. Sporulation of the albinotic isolates decreased significantly in PSA medium. The analysis of rDNA-ITS sequences showed that they shared 99.6% similarity to the known wild isolates of U. virens, and their rDNA-IGS sequences belonged to the most common type, consisted of 2 repetitive units of 77bp in the central various region. It is suggested that these albinotic isolates were the mutants of sporulating degeneration of Ustilaginoidea virens. The albinotic isolates could produce immature sclerotia in 30 days in PSA and UV irradiation could promote the formation of selerotia. The immature sclerotia could not germinate.