杯鞘石斛链格孢病菌生物学特性

Biological characteristics of Alternaria tenuis Nees on Dendrobium gratiosissimum Rchb. f.

对杯鞘石斛链格孢病菌的生物学特性进行了研究,结果表明,温度、p H值、光照、碳源和氮源对其生长和产孢有一定的影响。链格孢病菌最适宜生长的温度是25℃,在40℃几乎不能生长;最适宜的p H值为5~6;25℃12 h/12 h(L/D)光暗交替培养产孢量最多;能较好地利用蔗糖、葡萄糖、乳糖和淀粉碳源,但对不同的碳源利用有差异;供试氮源中,在含硝酸铵的培养基中菌落生长直径最大,而含甘氨酸的培养基中菌落生长较差。

Biological characteristics of Alternaria tenuis Nees on Dendrobium gratiosissimum Rchb. f. were studied.The results showed that temperature,p H,light,carbon source and nitrogen source affected the growth and sporulation of the fungus. The optimal growth temperature was 25 ℃,while Alternaria tenuis Nees almost could not grow at40 ℃. The optimal p H was 5. 0-6. 0. The optimal light conditon for sporulation was 12 h lighting and 12 h dark circle in a day at 25 ℃; Sucrose,glucose,lactose and starch could be used as carbon sources at different level in PSA medium. So did the nitrogen sources. Colony diameter was the biggest when NH_4NO_3 was used as nitrogen source,while smallest when glycine was used as nitrogen source.