<正>真菌的分类是以有性阶段作为分类基础的,它包括鞭毛菌(Mastigomycotina)、接合菌(Zygomycotina)、子囊菌(Aseomyeotina)和担子菌(Basidiomycotina)。但在自然界还有一类真菌,它们的有性阶段从来没有发观或者很少发现,而经常地以无性孢子进行繁殖,人们把这类真菌统称为半知菌(Deuteromycotina;Fungi Imperfecti)。 半知菌在自然界分布广,种类多,已知有1825属,15000种(Ainsworth,1971),在数量上仅次于子囊菌,其中有许多寄生在植物及动物体上。有半数左右的植物病害是由半知菌所引起的。半知菌现在一般分为两个纲四个目:丝孢菌纲(Hyphomycetes)和腔孢菌纲(Coelomycetes);前者包括丛梗孢目(Moniliales)和无孢菌目(Mycelia Sterilia),后者包括球壳孢目(Sphaeropsidales)和黑盘孢目(Melanconiales)。

In the nineteenth century, the taxonomy of the Fungi Imperfecti (Deuteromyco-tina) was almost entirely based on superficial morphological characters of fructification, conidiophore and ccnidium. Saccardo (1886) divided the Deuteromycotina into orders, families and genera by the morphology of sporulating structures and color, shape, septation and size of conidia. His system has been in use most widely by mycologists all over the world, bat as it contains many criteria depending upon changeable and unstable characteristics, it was criticized by many workers.At the beginning of the twentieth century, Vuillemin (1910-12) first pointed out that, conidium typss based on their ontogeny could be useful in classification. His concept was carried on by Mason. Their works inspired Hughes who (1953) proposed an experimental classification for Hyphomycetes, in which eight sections were recognized. Most emphasis was given to different types of conidium development, and the Saecardoan criteria were relegated to secondary importance. Hughes’ system was accepted and modified by various authors including Tubaki (1958, 1964), Subramanain (1962), Barron (1968) and others.The International Conference on Criteria and Terminology in the Classification of Fungi Imperfecti was held at Kananaski, Canada in 1969. In this conference it was recognized that conidia in the Deuteromycotina develop in two basic ways, thallic and blastic, which can be subdivided into categories based on fundamen’al differences in wall relationship between the conidium and the conidiogenous cell.Now much progress has been made in the Hyphomycetes of conidium ontogeny, but a lack of knowledge about the type of conidia in some genera prevents elaboration of a complete classification. Though Saccardo’s system has its inherent demerits, we can not abandome it but let it remain in use for convenience until a new comprehensive clasificatory system is fully derived and accepted by majority of workers.