关键词: 茭白(Zizania latifolia)胡麻叶斑病, 稻平脐蠕孢(Bipolaris oryzae), 产孢条件

Abstract: To investigate the biological characteristics of Bipolaris oryzae and screen methods for rapid and massive conidium production on artificial media, forty-three strains of the pathogen causing sesame leaf spot on Zizania latifolia were used as experimental materials. The colony growth diameter under different media and light durations was measured using the cross method, and conidial yield under different media, light durations, and mycelial damage conditions was determined using a hemocytometer. The results showed that the optimal medium for mycelial growth was V8, with a growth rate of 0.75 cm/d, followed by PDA medium. Light duration had no significant effect on mycelial growth. The optimal medium for conidium production was Zizania latifolia stem juice agar (WA+WBS), yielding 2.07×10⁵ conidia/mL after 10 days of culture. Under mycelial damage conditions, the conidial yield reached 1.213×10⁶ conidia/mL after 20 days of culture. Light significantly affected conidium production, with the optimal condition being an alternating 12-hour light/12-hour dark cycle. Therefore, selecting an appropriate medium promoted mycelial growth and conidium production, offered the advantages of rapid sporulation and high yield, and was a suitable method for inducing conidium production in the Zizania latifolia sesame leaf spot pathogen.

Key words: Zizania latifolia sesame leaf spot, Bipolaris oryzae, sporulation conditions