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细辛核盘菌 Sclerotinia asari Wu et C.R.Wang.在罹病细辛的地上部及整个根部可以形成大量茵核;这些菌核能否直接萌发侵染或形成有性世代借空气传播。这是病害侵染循环中的中心问题。试验结果表明:细辛核盘菌的菌核在自然条件下难以直接萌生菌丝体而发生侵染;而它的主要萌发形式是产生子囊盘,由于子囊盘的产生对湿度条件要求比较严格,因此其萌发机率较低,而且其子囊孢子因受树叶阻隔,也不易放射传播。菌核可在春秋两季萌发,但秋后因天气寒冷,只能形成子囊盘柄,不能出土,春季子囊盘出土起始于4月15～20日,终止于5月20日左右。子囊孢子放射起始于4月26日,终止于5月19日。子囊孢子的寿命为48小时至33天,子囊孢子以在细辛汁液中最易萌发,并只能从叶部伤口侵入,致病力较弱,构成初侵来源的可能性极小。如果排除有性世代的空气传播,细辛菌核疫病则应确定为捡疫性病害。根据 Adams 和 Ayers(1979)报道,有许多 Sclerotinia SPP 的子囊孢子可以藉风力传播而产生侵染,杨新美(1961)、H.J.Willetts et J.A.—L Wong(1980)等也报道 Sclerotinia sclerotiorum 的主要侵染来源是子囊孢子;而 S.minor的菌核可直接萌发侵染致病。细辛核盘菌能够在病田中产生大量菌核,但它究竟能否萌发产生侵染或产生子囊孢子借空气传播,这是病害侵染循环中的一个中心问题。为弄清这个问题,作者从1979～1984年对细辛核盘菌菌核的萌发、有性世代的产生及其侵染规律进行了系统的研究,本文报道这方面的试验结果。
Sclerotinia asari Wu et C.R.Wang. In the pathogenic Asarum aboveground and the entire root can form a large number of Yin nuclear; these bacteria can directly germinate infection or the formation of a sexual generation by airborne. This is a central issue in the cycle of disease infestation. The results showed that: Sclerotinia sclerotiorum hard to directly in mycelium under natural conditions and infection; and its main form of germination is the production of ascus plate, since the production of ascus plate humidity conditions are more stringent requirements, So its chance of germination is lower, and its ascospores are blocked by leaves and are not easy to spread by radiation. Sclerotia can germinate in the spring and autumn, but it is cold in the autumn and can only form the ascaps and can not be unearthed. The spring ascus excavated from April 15 to April 20 and ends on May 20. Ascospore emission starts on April 26 and ends on May 19th. Ascospores have a lifespan of 48 hours to 33 days. Ascospores are most likely to germinate in asarum juice and invade only from the leaf wound, with less virulence and minimal possibility of being a source of initial invasion. If the airborne sexual generation is excluded, ascocidosis should be identified as an epidemic. According to Adams and Ayers (1979), many Ascospores of Sclerotinia SPP can be infected by infection by wind, and Yang Xinmei (1961), HJ Willetts et JA-L Wong (1980), etc. also reported the main source of infection of Sclerotinia sclerotiorum Is ascospore; and S. minor sclerotia can directly germinate infection pathogenic. Aspergillus nidulans can produce a large number of sclerotia in the disease field, but whether it can germinate and produce infection or produce ascospores to spread by air is a central problem in the cycle of disease infection. To clarify this issue, the author systematically studied the germination, sexual generation and infection of Sclerotinia sclerotiorum from 1979 to 1984, and the experimental results in this field are reported in this paper.