Diversity Of Mangrove Endophytic Pestalotiopsis In Hainan And Molecular Phylogenetics Of Pestalotiopsis

Pestalotiopsis were a major group of endophytic fungi. There were 235 Pestalotiopsis species were recorded of which were plant pathogens mostly. There have fourteen seven species of Pestalotiopsis been recorded as endophyty since Espinosa-Garcia et al. firstly reported Pestalotiopsis funerea as an endophytic fungus in Sequoia sempervirens in 1990.As a part work of the National Natural Science Foundation of China Grants item"Resources and diversity of endophytic Pestalotiopsis in Mangrove and taxonomic study for Pestalotiopsis", the investigation of endophytic Pestalotiopsis diversity for Mangrove plant in Dongzhai gang Mangrove Nature Reserve in Hainan was carried out, ITS and beta-tubulin gene sequences were amplified for selected representative strains and Appraisement of several morphologic target for their phylogenetic significances in the taxonomy of genus Pestalotiopsis were explored.Main research contents were showed in the following:1. Species of mangrove plant endophytic Pestalotiopsis in HainanIn a survey of endophytic Pestalotiopsis species in mangrove plants in Dongzhai gang Mangrove Nature Reserve of Hainan province from 2007 to 2008, a total of 77 Pestalotiopsis species belonging to 28 families were isolated from 11 mangrove plants.2. Diversity of mangrove plant endophytic Pestalotiopsis in HainanColonization frequencies of endophytic Pestalotiopsis varied with the host plant and different tissue of the same plant. For example, Colonization frequencies of endophytic Pestalotiopsis in Kandelia candel was 20%, but only 2% in Bruguiera gymnoihiza.The colonization in branche of Sonneratia paracaseolaris was 17%, higher than leaves, which was 13%. However, the colonization in Lumnitzera racemosa leaves was higher than that in branches. The species of endophytic Pestalotiopsis is closely related with their host plants.Shannon-Wiener index of endophytic Pestalotiopsis in mangrove plants changed from 0 to 2.1026. Evenness index changed from 0 to 1. Richness index of endophytic Pestalotiopsis had no correlation with Shannon-Wiener index, but had closely correlation with evenness index.3. Reappraisement of pigmentation of median cells for its phylogenetic significance in the taxonomy of genus PestalotiopsisThe stability of pigmentation of median cells of conidia in Pestalotiopsis species was evaluated in subculture, and a molecular phylogenetic analysis was conducted on 45 strains belonging to 26 species in order to reappraise the pigmentation of median cells for its significace in taxonomy of the genus Pestalotiopsis. Phylogenetic relationships were inferred from nucleotide sequences in ITS regions (ITS1, 5.8S and ITS2) and beta-tubulin 2 gene (tub2) under maximum parsimony. The results showed pigmentation of median cells was stable and was a key character in the taxonomy of Pestalotiopsis species. Instead of"concolorous"and"versicolor"proposed by Steyaert (1949),"brown to olivaceous"and"umber to fuliginous"as the two types were impartially described and proposed in this paper for the taxonomy of Pestalotiopsis, The two types of pigmentation of median cells were identical to the two groups in the molecular phylogenetic tree.