Development of Molecular and Biochemical Markers for Selecting a Potential High Yielding Strain of Paddy Straw Mushroom (Volvariella volvacea)

Abstract

Twelve ‘normal type’ strains of paddy straw mushroom (Volvariella volvacea) varied in their mycelial growth characteristics, and the fast growing strains, OE-215, OE-209 and OE-212 exhibited higher activity of cellulases, but not of laccase and polyphenol oxidase. In protein profiles, out of twelve, two strains, OE-210 and OE-273 varied only at one protein band with respect to its intensity. The four strains, OE-272, OE-140, OE-209 and OE-55 with higher activity of endoglucanase, β-glucosidase, xylanase and laccase, were also recorded to have higher protein content in their mycelial cultures. The RAPID profiles obtained with 5 OPB series primers varied in different strains and the combined phylogenetic analysis of the RAPID profiles revealed 5 distinct phylogenetic clusters, where in the strains with common origin showed 85% to 95% similarity. The strain, OE-210, with a low intensity protein band in its protein profile also varied in mycelial growth rate on two different media, possessed highest activity of endoglucanase, β-glucosidase, laccase and polyphenol oxidase and also showed highest dissimilarity of 28% with other strains in phylogenetic analysis. The present study thus, reveals that strains with faster mycelial growth rate, forming aerial mycelia and chlamydospores, also exhibited higher activities of xylanase, exoglucanase, endoglucanase or β-glucosidase, while simply higher activity of an individual enzyme was not found sufficient to support the mycelial growth and mushroom yield. A relationship between origin of the strains and their phylogenetic belongingness was also recorded, as the strains from different origins formed different clusters in combined phylogenetic analysis.