Studies On Species Diversity Of Rhytismataceae On The Evergreen Rhododendron Plants From Anhui And Molecular Identification Of Lophodermium Conigenum And L. Australe

Rhytismataceae and its related groups are an important part in fungi resources of the world, which are distributed worldwide. Some members of Rhytismatales on the evergreen Rhododendron plants from Anhui were systematically studied by the synthetical classification means on multiple character and according to phenotypic character, such as morphology, ontogeny, ecology, and distribution. At the same time, Lophodermium conigenum and related species L. australe were identified and classified to definite the relationships in interspecies and genetic diversity in intraspecies on the basis of Phenotypic character and the sequences of rDNA-ITS region. The main result is as follows:1. Dry specimen on the evergreen plants of Rhododendron in Anhui from own collection and the Herbarium of Forest Fungi of Anhui Agricultural University (AAUF) were identified and classified according to the taxonoic principles of Darker (1967), Cannon & Minter (1983, 1986), Johnston (1986), Spooner (1991)and Kirk et al. (2001). 7 species of Rhytismatales were studied, including C. leptideus of Coccomyces, L. implicatum, L. pachychilum, L. rufum, L. urniforme and L. validum of Lophodermium, N. rhododendri of Neococcomyces. L. urniforme is a new specie among them. Dichotomous key to these species were complied. Morphological characteristics were described and illusteated, and habits, hosts and distributions wre recorded for the species.2. Morphological characters and ecological habit, etc. of Lophodermium conigenum and related species L. australe were compared; besides, rDNA-ITS region of eight strains of the two species was amplified and sequenced, and phylogenetic trees were constructed based on these sequences as well as sixteen related ones in GenBank. Phenotypic characteristics of L. conigenum are remarkably similar to those of L. australe, except shape of ascomata, stroma basic layer, zone lines and parasitism. G+C content of L. conigenum (51.0%) is less than that of L. australe (54.0%). The phylogenetic analysis shows the two related species are sharply classified into two independent groups, which are consistent with the classification based on phenotypic characters. The interspecific and intraspecific genetic diversity is closely related to hosts, but not to distribution. The comparison analysis of phenotypic characteristics and ITS sequences could be used to distinguish L. conigenum and L. australe accurately.