| Members of Rhytismataceae which collected from the Wanfoshan National forest park of Anhui province were systematically studied with the most novelty and advanced poly-character integrated taxonomy method which is based on the characters of morphology, developmental biology, ecology and distribution, and culture characters etc. At the same time, rDNA-ITS sequences of 13 strains were amplified and determinated and the genetic homology between these sequences and other related sequences in GenBank were analyzed for the two related species of Lophodermium, L. pinastri and L. pini-excelsae. A phylogenetic tree of these strains was constrcuted by MEGA, using neighbour-joining method. Results indicated the importance of some morphological characters and the category of hosts on the classification of species level. Genetic diversity and relationships of some intraspecific and interspecific strains of two related species were further affirmed.Some samples of Rhytismataceae from the park were systematically studied according to the taxonomic principles of Darker(1967),Korf(1973),Cannon & Minte(r1983,1986),Johnston(1986),Spoone(r1991),Kirk et al.(2001). 11 species among 5 genera were identified. The 5 genera were Coccomyces, Lophodermium, Hypoderma, Soleella and Terriera. Among the taxa, Terriera was a newly recorded genus from China, T.huangshanensis was a new species, and T.minus was a new record for China. The studies of 9 known species involved in adding characters of morphology, development biology, new record of host and geographical distribution. Morphological characteristics were described and illustrated, and hosts and distribution were recorded for all the species, and their similar groups, parasititism and nosogenesis were discussed. Dichotomous key of the species was compiled.Terriera is distinguished from Lophodermium by the absence of lip cells, the extension comprising strongly carbonized tissue with no obvious cellular structure, the excipulum closely adhering to sides of the covering stroma, the subhymenium with a region of near-colorless or ficelle, hyaline, textura prismatica or textura angularis at the edge of the ascoma, and the paraphyses sometimes swelling at the apex and agglutinating to form a dark epithecium. Hypoderma is similar to Terriera, but differs in the usually well-developed lip cells, the paraphyses swelling rarely at the apex, and the ellipsoidal, cylindrical to clavate ascospores. T.huangshanensis on leaves of Eurya muricata var. huiana (Kobuski) Hu & L.K. Ling, is placed in the genus Terriera on the basis of the presence of strongly carbonized extension adjacent to both sides of the ascoma opening, poorly developed angular cells in the tissue at the marginal parts of the ascoma and the absence of lip cells. T. huangshanensis is miraculous within the genus because of the asci synchronously ripening and the hymenium often overtopping the extension of the covering stroma when mature.The results showed that important characteristics of L. pinastri were remarkably similar to those of L. pini-excelsae, except those of stroma basic layer, zone lines and opening of conidiomata. G+C content of L. pinastri(51.5%) was more than that of L. pini-excelsae(50.1%). The phylogenetic tree indicated that 13 strains of L. pinastri on diploxylon pines and L. pini-excelsae on haploxylon pines were sharply classified into clade I and clade II respectively; clade I was comprised of clade A and clade B; 7 strains of L. pinastri from Pinus. sylvestris and P. nigra, which were the European native trees, formed clade A; clade B consisted of 4 strains of L. pinastri from P. densiflora and P. densiflora cv.'Umbraculifera'; clade II was composed of 2 strains of L. pini-excelsae from P. parviflora and P. armandii respectively. It can be seen from this that hosts had a definite impact on intraspecific genetic diversity and origin was not significantly associated with intraspecific genetic difference. ITS sequence analysis was an effective means to distinguish the two related species. |
PDF Full Text Request