Genetic Diversity For Cultivated Strains Of Pleurotus And Its Epiphytic Bacteria Response To Ecological Factor

Fungi of Pleurotus are a wide range of intimate relationship with humans, ahigher nutritional value and an important economic value and medicinal value ofedible and medicinal fungi. However, due to the lack of administrative controlrelating to these strains and morphological plasticity, possible environmental effects incultivation, it is common that the identical strains have different names or differentstrains have the same name. Incorrectly designated strains can result in greatinconvenience and loss for scientific research and production. With the developmentof modern biotechnology, a number of new methods and technologies continue toemerge. In this study, species identification and analysis genetic diversity base on theLSU rDNA sequence, ITS sequences and SSR molecular markers in main cultivatedstrains of Pleurotus, in order to provide a reference of the production of fungi to usescientific research and beneficial to its germplasm resources protection.This study using PCR product direct sequencing acquires ITS and ribosomalDNA large subunit (LSU of rDNA) sequences of54Pleurotus strains, sixcomparision species with ITS and LSU rDNA sequences are found in GenBanksequence. Phylogenetic tree is constructed based on ITS and LSU rDNA sequence ofeach strain except two strains of Pleurotus nebrodensis with six comparision speciesshows that species identification using LSU rDNA sequences than traditional ITSsequences analysis is more convenient, stable and reliable;54main cultivated strainsof Pleurotus were divided into two species: Pleurotus ostreatus and Pleurotuspulmonarius.Develop and characterize microsatellite loci from the DNA of Pleurotus usingFIASCO (Fast Isolation by AFLP of Sequences Containing repeats), Primers aredesigned based on the separation of microsatellite DNA sequences.18polymorphicmicrosatellite markers are screened,18SSR primer pairs created396DNA bandsranging in size100to400bp, which analyzing by Cluster analysis, based on UPMGAfrom SSR markers among the fifty-four strains. The result show that every SSRmarkers produced4-32alleles, the polymorphism information content (PIC) of theseSSR ranged from0.35to0.94, the similarity coefficient between cultivated strainsvaried from0.755to0.9995. The dendrogram based on the similarity coeffcientfound that the54strains were divided into three distinct groups Pleurotus ostreatus,Pleurotus pulmonarius and Pleurotus nebrodensis. The clustering show the different strains of same specie clustered into the same branch. To identify the species, fruitingexperimental, antagonism experiment and ISSR molecular markers show thatACCC50618, ACCC50866and ACCC50915are the identical strains have differentnames; ACCC50249with ACCC50476for the identical strains have different names,the results consistent with the SSR analysis.In order to determine the relationship between epiphytic bacteria of the Pleurotusfungi and ecological factors.In this study, the samples of Pleurotus ebrodensiscollected in Shou County of Hebei, ji County of Tianjin and laboratory Pleurotusroom, through16SrDNA sequence, the diversity of epiphytic bacteria were analyzed.The predominant strains are Arthrobacter sp., Pseudomonas sp.. The temperature hassome influence on the quantity and composition of epiphytic bacteria, fruiting highertemperatures will lead to richer the diversity of epiphytic bacteria. To exploring byartificial means or control of the environment to change the type of epiphytic bacteriaand maximize the beneficial organisms, self-control role, disease prevention andcontrol to provide a theoretical basis.