Genetic Diversity Of Pheromone Receptor Genes In Mating Type B And Pleurotus

In Yunnan province, complex topography, different altitude, soil types, as well as tropical, subtropical, temperate climate types formed the unique diversity of the ecological environment, which provide a good environment for edible fungus growth and reproduction. From molecular phylogenetic aspects, taxonomic identification of Auricularia and Pleurotus were analyzed based on ITS sequences.The phylogenetic relationship and diversity was analyzed of Auricularia and Pleurotus strains from different regions according to cloning pheromone receptor of mating type gene B loci.The main results of the study are as follows:(1) Phylogenetic results based on ITS indicated the identification of five Auricular species that included A. delicata, A. peltata, A. Americana, A. auricula-judae and A. cornea. A. delicate were found to be phylogenetic and distributed into two clades, the Asia species and the America species. Phylogenetic results based on ITS sequences of Pleurotus indicated that experimental strains distributed in four different branches corresponding four species.The relationship is very close between P. pulmonarius and P.sajor-caju, thus P. sajor-caju was revised P. pulmonarius. ITS region could be used to evaluate species identification in same genus.(2) Degenerate primers brl-F and br2-R were employed based on the conservative amino acid sequence of STE3 pheromone receptor in Schizophyllum commune. In the research,51 and 89 gene fragments of pheromone receptor were amplified from 15 and 28 wild strains of Auricularia and Pleurotus in Yunnan province China using degenerate PCR methods. Two to six discrepant fragments were amplified from each strain. Combination of phylogenetic result on ITS and pheromone receptor gene both Auricularia and Pleurotus, the following conclusion were obtained:Both geography origin and altitude are determinants of the distributions of Auricularia and Pleurotus, and strains from similar geography origin cluster together easily. Thus these factors result in abundant species diversity. This could provide basis for ecological distribution analysis of Auricularia and Pleurotus. Moreover, the phylogenetic results based on the pheromone receptor revealed that there are similar pheromone receptor sequences among different species and genus and the sequences formed a clade. This indicated that the origin of the conserved pheromone receptor gene is diversiform and complex. In light of the highly conservation and these pheromone receptor gene could not be the indicator as species identification. Fragments from same strain were randomly distributed with rich diversity. In Auricularia and Pleurotus, most pheromone receptor fragments are special, which could be the indicators as genus identification. Moreover, the high special receptor genes could be used for species identification, genetic evolution analysis and breeding research in the future.(3) Phylogenetic analysis on amino acids sequences of pheromone receptor gene of Auricularia and Pleurotus as well as other partial basidiomycetes was discussed. The result showed:(1) The partial pheromone receptor gene, because of the high similarity, formed a clade in different genus; (2) Other pheromone receptor gene showed specificity in species and genus, which indicated different pheromone receptor gene playing different roles in mating recognition.