蛹虫草病原真菌虫草生齿梗孢Calcarisporium cordycipiticola的生物学特性研究

蛹虫草已经成为我国乃至东南亚地区极其重要的食药用真菌,虽然其子实体已经实现规模化生产,但在产业发展中遇到许多问题,真菌病害为其中之一,如引起蛹虫草“白毛病”病害的虫草生齿梗孢Calcarisporium cordycipiticola。本研究以虫草生齿梗孢为对象,研究了其生物学特性、发病特性及侵染特点。结果表明：该病原菌菌丝分枝较多,短时间内产生大量分生孢子;最适生长温度为25℃,此温度有利于该病害快速传播;其分生孢子比蛹虫草分生孢子耐紫外能力强。栽培过程中该病害多发生在蛹虫草生长发育后期,可以侵染培养基表面、子实体底部、中部和顶端等各个部位。人工接种发现该病原菌可以侵染蛹虫草生长发育的任意阶段,后期子实体被白毛覆盖。对峙实验发现虫草生齿梗孢菌丝逐渐生长到蛹虫草菌丝上,但未发现两菌丝互相缠绕的现象。对该病原菌基本生物学研究,将为建立该病害的早期检测及预防方法提供依据。

Biological characterization of the fungicolous fungus Calcarisporium cordycipiticola,a pathogen of Cordyceps militaris

Cordyceps militaris has become one of the well-known edible and medicinal fungi in China and Southeast Asia. Although the fungus has been successfully cultivated and commercialized, it has encountered many problems in industrialized production, e.g. fungal disease caused by Calcarisporium cordycipiticola. In this study, the biological characteristics, pathogenicity and infection characteristics of this parasite were investigated. It was found that the branchy mycelia could produce a large number of conidia in a short time. The optimum growth temperature was 25°C, favouring the rapid spread of the disease. The conidia of the pathogen were more resistant to UV than those of C. militaris. The disease occurs in the later stage of the growth and development of C. militaris, and it can infect the surface of the cultures, and the bottom, middle and top of the fruiting bodies. Inoculation of conidia revealed that the pathogen could infect C. militaris at any stage of growth. Co-cultivation test indicated that C. cordycipiticola could gradually grow onto the mycelium surface of C. militaris. However, intertwinement of the mycelia of both species was not found. This study provides a reference for early detection and prevention of this disease during mass production of C. militaris.