稻曲球及稻曲病菌菌落微结构的SEM观察

本文对不同培养条件下稻曲病菌菌落及稻曲球的微结构进行了扫描电镜比较研究。在PS培养液里进行液体培养时,稻曲病菌很少产生分生孢子和厚垣孢子,只有培养后期漂浮在培养液表面的菌落可以产生大量的厚垣孢子。病原菌在进行PSA固体培养时,大部分菌株在培养后期产生大量的成堆分布的厚垣孢子,少部分菌株在菌落上产生散生的厚垣孢子。说明暴露于空气有助于稻曲病菌产生厚垣孢子。在煮熟的带壳谷粒上稻曲病菌的生长明显比在去壳上的要慢得多。微结构分析表明,稻曲球表面是一层密集的厚垣孢子,菌丝与稻粒的胚乳层界限分明,大部分稻曲球中部有大块的发育良好的胚乳,并充满密集的淀粉粒。说明稻曲病菌可能在开花灌浆后开始侵染,而且至少后期是腐生的。

SEM observation of rice false smut balls and colony microstructure of Ustilaginoidea virens

The comparative studies on the microstructure of rice false smut balls and colonies of Ustilaginoidea virens on different media were conducted by SEM. There was only a few of chlamydospores and conidia formed by hypha balls of the fungus in potato saccharose (PS) liquid medium. The colonies on patatp saccharosr agar (PSA) medium could produce abundant chlamydospores, usually forming many chlamydospore balls around the colonies or dispersing on the whole colonies in a few isolates. This implies that the exposure to air favors producing chlamydospores. In the false smut balls, the outer dense chlamydospores piled around the hyphae. The growth of the fungus in the cooked unhushed barley and rice grains was much slower than that in the cooked wheat grains and milled rice grains. There was no crossed interface between the hyphae and endosperm, and there was a large stretch of well developed endosperm in the center part, in which a great amount of starch grains filled. These suggest that the infection of pathogen may occur after flowering and grouting, and the pathogen may be saprophytic.