Application Of Molecular Marker In Germplasm Resource Of Four Pleurotus Species

At present, we have identified 31 species of the genus pleurotus. About ten species were cultivated as edible mushrooms. It has been reported that, in 2004, China' s mushroom production was over 11．6 million tonnes, which accounted for about 75% of the world total production. At the same year, the production of the edible species of the genus pleurotus reached about 3 million tonnes, which gained world prominence.In my paper, four molecular markers, namely RAPD, SRAP, ISSR and ITS of rDNA, were applied in four pleurotus species, which were Pleurotus geesteranus Singer, Pluwrotus abalonus Han, K.M.Chen et al., Pleurotus pulmonarius Fr. Sing and Pleurotus cystidiosus O.K. Miller, to analyze genetic diversity and relationships within and between species.During research, I discovered that, applying two or more than two molecular markers can be more exact to analyze genetic diversity in mushroom species. Molecular marker technique, combining with the other techniques such as morphological character, is easier to identify disputed strains.In my studies in identification of 34 cultivated strains of Pleurotus geesteranus Singer with the use of molecular markers, dendrogram of UPGMA cluster analysis revealed that Pl. g0017, Pl. g0018 and Pl. g0019 had close evolution relationship, which suggested that the three strains may belong to the same strain with different names. This situation also occurred in the Pl.g0029, Pl. g0030 and Pl. g0031．Based on the dissimilarity coefficient of 0．57, 34 cultivated strains were divided into 8 groups.Pluwrotus abalonus Han, K.M.Chen et al. and Pleurotus cystidiosus O. K. Miller have the similar morphological and biologic character, so the two species are often confused. After analysis, I discovered that Pl. a0002 strain should be Pleurotus cystidiosus strain but not Pluwrotus abalonus strain, and Pl. a0004 strain should not be Pluwrotus abalonus strain, whose analysis of ITS revealed that it may be Pleurotus ostreatus strain. At the same time, I discovered that Pl. a0014 and Pl. a0015 had close evolutional relationship, which indicated that they may belong to the same strain with different names. Based on the dissimilarity coefficient of 0．57, 16 cultivated strains of Pluwrotus abalonus were divided into 5 groups.After the analysis of 9 cultivated strains of Pleurotus pulmonarius Fr. Sing, I discovered Pl. p0006 strain is not Pleurotus pulmonarius strain. Its fruiting body is different from other Pleurotus pulmonarius strains. The analysis of molecular markers suggested that it may be Pleurotus ostreatus strain. Based on the dissimilarity coefficient of 0．58, 9 cultivated strains were divided into 5 groups.The analysis of 16 cultivated strains of Gaowen Pinggu showed that Gaowen. Pinggu is not taxonomic species. It should be considered as a trade name. Gaowen Pinggu included many pleurotus strains. Because they are cultivated at the same high temperature, people call these strains Gaowen Pinggu. Based on the dissimilarity coefficient of 0．58, 16 cultivated strains of Gaowen Pinggu were divided into 5 groups.