稻曲病菌分生孢子的生物学研究

Study on biology of conidia of Ustilaginoidea virens

本文对稻曲病菌分生孢子的一些生物学特性进行了研究 ,结果表明 ,基质养分对分生孢子萌发影响较大 ,纯水不利于孢子萌发 ,PSA最适于孢子萌发 ,葡萄糖则强烈抑制孢子萌发 ,马铃薯煮汁既可抵消葡萄糖的抑制作用 ,又可刺激孢子萌发。分生孢子在琼脂面上比在液滴中萌发率高。分生孢子萌发的适宜温度为 2 2～ 31℃ ,以 2 8℃最好。分生孢子萌发对pH值敏感 ,以pH 6～ 7最适宜。用振荡培养法获取分生孢子 ,培养 10d后 ,孢子的萌发力开始下降。分生孢子的存活对水的依赖性强 ,在水中保存8d萌发力不变 ,在 10 0 %RH中 8d萌发力略有降低 ,而在 2 5 %RH中 5h萌发力即迅速下降。根据这些特性 ,作者对分生孢子在田间的动态作了一些推测。

The study on biology of conidia of Ustilaginoidea virens (Cke.) Tak. indicated that nutrient in media had an important effect on germination of conidia. Pure water was not good for germination. PSA was the optimum media for germination. Glucose inhibited germination strongly. Potato juice could counteract the inhibition of glucose and stimulate germination. The germination rate was higher in solid agar media than that in liquid media. The suitable temperature for germination was 22-31℃, with the optimum of 28℃. The pH value had a sharp effect on germination, and pH 6-7 was optimum for germination. The germination rate of conidia began to decrease after growing 10 days by shaking culture. Water had a significant effect on viability of the conidia. In the case that conidia were kept in water for 8 days, germination rate of the conidia did not decrease, and in the case that they were kept in 100% RH for 8 days, the germination rate declined slightly, but in the case that they were kept in 25% RH for 5 hours, the germination rate dropped sharply. Based on these cha- racteristics, hypothesis about behavior of the conidia in the field was proposed.