洋菇白黴病之研究

Studies on Soft Mildew of Mushroom

洋菇白黴病（Cladobotryum variospermutn）以白色菌絲體在覆土上蔓延，當其擴及洋菇時，菌絲纏繞菇上並侵入菇體使之變褐色的腐敗。病菌有輪生分枝之胞柄和橢圓形中央有一橫隔膜之胞子。本菌在8℃以下32℃以上均不能生長，20~30℃為最適宜生長範圍，但以28℃最佳。葡萄糖含量0.1%時菌絲伸長最速，濃度增加則菌絲生長反而轉慢，生長兩天後即有胞子形成，在含葡萄糖0.1%時產生胞子最多。麥芽糖、澱粉、糊精為菌絲生長良好之碳素源，天冬精為適宜生長氮素源，在麥芽糖與天冬精之培養基亦能形成胞子。

Soft mildew or cobweb disease of mushroom in Taiwan was caused by Cladobotryum variospermum ((Link.) Hughes. The white weft of the pathogen started from the surface of the caning Soil and enveloped all mushroom in its path. The enveloped mushroom decayed rapidly and became a soft putrid mass. This pathogen produced verticillate or sometimes irregular branching conidiophore and hyaline, usually on-septate phialospores. The optimum temperature for the growth of pathogen was ranged from 20-30℃ and the best growth occurred at 28℃, No growth was detected when the fungus was incubated below 8℃ or above 32℃. The mycelium grew most rapidly when it was cultured in the medium which contained least sugar (0.1% Glucose). Increasing the concentration of glucose in the medium decreased the diameter growth of the colony. The fungus formed spores readily and most abundantly after growing on the medium (0.1% Glucose) for 2 days. Maltose, soluble starch and dextrin were the suitable carbon sources for growth and asparagine as a good nitrogen source for the same purpose It Sporulated well on a maltose-asparagine medium.