Strains Identification Base On Mycelium And Molecular Systematic Studies

Morchella sp. is a kind of economic fungi that have important edible and medicinal value. Although recently studied on the aspects of morphology, biology, taxonomy and molecular biology have some results, but there remain many problems: (1) There is no uniform standard of identification based on the mycelium ; (2) It still have differences about division of the species.In this study, identify the 18 strains whether Morchella sp. based on mycelium character of morphology and molecular. Sequence ITS sequences of 18 strains and identify the various strains of Morchella sp. searching Genebank database. Finaly confirmed 50536, 50537, 50647, 50648, G5241 are not Morchella sp.. Morphological comparison by mycelium observed, the mycelia of Morchella sp. can be divided into the surface hyphae and within hyphae. Surface hyphae have obvious trunk, straight, shiny, initial white or light yellow, radiation growth, the latter gradually become yellow to brown, multi-branched, branches can be divided into two categories. One is sub - class trunk; another stretch into culture medium forming within hyphae. Within hyphae are short and thick, no backbone, and color is relatively shallow. Morchella sp. can distinguish from other fungal strains with this feature.To compare the ITS sequences of 13 Morchella sp. ascertain homologous. Molecular phylogenetic tree constructed using maximum parsimony method (MP) and neighbor-joining method (NJ) for distinguish each kind of Morchella sp. and phylogenetic relationships. The results show that, Morchella sp. can be divided into two taxa, one type of ITS sequences longer (1098-1172), including species M.esculenta and M.crassipes; and other type of the ITS sequence short ( 698-702), including strains M.conica and M.costata. The study results support that Morchella sp. is divided into yellow and black, and the yellow of the ITS sequences longer. The results of the above-mentioned is also consistent with the morphological characteristics. Through the ITS sequences, Morchella sp. can clearly be distinguished from each species.