广东稻曲病的研究稻曲菌生理特性及厚垣孢子微观特征

Studies on the rice Gieen Smut Ustilaginoidea virens(Cooke) Takahashi in Guangdong Province A Study on the Physiology of the Causal Organism and Its Chlamydospores Micro-Characters

广东稻曲菌厚垣孢子常温下存活期为５．５～６个月。温湿度对孢子存活期有明显影响，在４～６℃低温干燥条件下，存活期延至８个月以上；而在２８℃以上高温高湿条件下，大为缩短，两个月内丧失发芽力。２％葡萄糖、蔗糖或麦芽糖对孢子萌发有利。病菌在ｐＨ３．５一８．５均可生长，以ｐＨ６．５～７．５较好。在ＰＤＡ，ＹＰＰＤ培养基上生长良好，而在Ｃａ，Ｍｇ，Ｋ，Ｎａ蔗糖琼脂培养基上生长极差。扫描电镜下，厚垣孢子呈菊花状，纹饰呈楔状突起，酷似菊花花瓣。

The surviving period of the chlamydospores of Ustilaginoidea virens was usual-ly founded to be 5.5～6 months hanged out the open air in Guangdong, it is similar tothat found in Japan. The temperature and humidity greatly influenced the surviving period of the chlamydospores,which was much prolongated under low-temperature(4～6℃)and dry weather,but much shortened under high-temperature (above 28℃)and humid weather, some of the chlamdospores could not genninate within 2 months. 2% solution of Glucose,Sucrose or Maltose were found to promote the gennina-tion rate of the chlamydospores, while 2% solution of Lactose, Rhamnose or Fructosewere not.The range of pH for the mycelium growth was pH 3.5～8.5 and the optimumwas pH 6.5～7.5.The growth of the causal organism was best on the PDA, YPPD andOat agar for artifical culture but worst on the Ca-Mg-K-Na sucrose agar. Under scanning electron microscope the chlamydospores appeared somewhat like achrysanthemum blossom.