Studies On Investigation And Morphologic And Molecular Identification Of The Genus Alternaria Nees From Some Areas Of China

The genus Alternaria Nees is a kind of imperfect fungi that is cosmopolitan and economically important. Over 95% species parasitize plants, which causes serious problems in agriculture by redudcing crop yield in the field and spoilage in storage. Several different Alternaria spp. are associated with mouldy rot of fruits, which causes economic losses in national export trade. Some small-spored Alternaria species can infect human beings and animals, and some mycotoxins produced by Alternaria are important carcinogens. On the other hand, Alternaria is one of the biologic resources that has potential application value. Secondary metabolites of some Alternaria have the function of killing pests, bacteria and protists for biocontrol. Some Alternaria species as endophytes can produce anticancer medicines. So there is important theoretic and practical significance for the accurate classification and identification of Alternaria.It is difficult to identify and classify most of the Alternaria species because of lack of telemorphs. Conidia and conidial structure are the basis in classical taxonomy of Alternaria. But morphologic characteristics will vary in a large scale under different conditions of medium, temperature, moisture, light, and pH etc., which makes the taxonomy of Alternaria confusing.Application of molecular biotechnologies has promoted the phylogenetic analysis of fungi. International studies on systematics of the genus Alternaria localized on 1-2 genes of strains collected from certain areas. The project supported by National Natural Science Fund of China—Studies on molecular systematics of the genus Alternaria Nees from China and the globe is to sequence several genes of the genomes of a series of strains from China and the globe to construct gene trees phylogenetically along with their GenBank alies with PAUP* software to identify certain species and determine their distributing scale. This paper carried out part of the NSFC project. This study is composed of 2 sections as follows: a. Studies on resource investigation and morphologic identification of Alternaria34 Alternaria strains were isolated from 212 samples collected from 11 provines and 1 municipal city of China. All the isolates were transferred to PCA medium and...