红麻灰霉菌生物学特性及其交叉感染

测定温度、光照、营养、pH对红麻灰霉菌孢子萌发、菌丝生长、产孢,以及湿度对孢子萌发的影响.结果表明,该菌孢子萌发、菌丝生长和产孢的适宜温度为20-22℃;孢子宜在水滴和水膜中萌发,孢子悬浮在红麻叶汁液中能显著提高萌发率;持续强光照可抑制菌丝生长和产孢,黑暗利于孢子萌发和菌丝生长.该菌在6种培养基上以PSA生长和产孢最佳.孢子萌发、菌丝生长和产孢以pH5-7为宜.从孢子侵入寄主的影响因素和菌核特性试验可以看出,该病在孢子含量为103-107个·mL-1范围时,其潜育期随孢子含量的提高而缩短;在相对湿度为100%下,用孢子叶汁悬液对叶片伤口喷雾接种能明显缩短潜育期.菌核埋入土层愈深萌发率愈低,夹在麻杆中的菌核皆能萌发.不同寄主灰霉菌交叉接种测定显示,红麻灰霉菌对莴苣、黄瓜、韭菜和蕹菜的健株不致病,反之,莴苣、蕹菜灰霉菌对红麻尤其是受伤的植株能致病.

Biological characteristics of Botrytis cinerea from kenaf and its cross infection

The effect of temperature, light, humility, medium nutrition and pH on spore germination, hyphal growth, spore formation of Botrytis cinerea from kenaf were determined. The results showed that the optimal temperature of spore germination, hyphal growth and spore formation of B. cinerea was from 20 to 22 ℃. During germination, the spores need to be in water drop or water film. Suspending in kenaf leaf juice would obviously improve the spore germination rate. The hyphal growth and spore formation were inhibited by continuous strong light and the dark was good for spore germination and hyphal growth. Among 6 media, PSA was the best and the optimal pH value in the medium was 5-7. The host infection test showed that the incubation time decreased with the increasing of inoculant contents ranging from 10~3 to 10~7 spores·mL~(-1), and also obviously decreased by spraying the spores which suspended on the leaf juice to wounded leaves. The sclerotium characteristic tests indicated that the deeper the soil in which sclerotium was embeded, the lower germination rate of spores had. All sclerotium in the kenaf caudex could germinate after winter. Cross inoculation test showed that B. cinerea from kenaf could not infect the healthy lettuce, cucumber, leek and water spinach. However, the pathogens from lettuce and water spinach were pathogenic to kenaf, especially to wounded plants.