Biodiversity and Genetic Variation of Ectomycorrhizal Fungus Pisolithus in India

Abstract

Fungi play fundamentally important and diverse role in terrestrial ecosystems, being newlineinvolved in many of the key processes required for ecosystem functioning. They are newlineimportant as pathogens of plants and animals, as mycorrhizal symbiont of plants and newlineas the main agent for decomposition of organic material. Mycorrhizal plants and fungi newlineare ecologically dependent; the successful establishment and function of the newlinemycorrhizal symbiosis often determine their survival, growth and fitness. newlineEctomycorrhizal fungi play an important role in functioning of most forest newlineecosystems by benefiting their hosts by nutrient acquisition, drought tolerance and newlinepathogenic resistance. Pisolithus are ectomycorrhizal gastereomycete genus with a newlineworldwide distribution and forms ectomycorrhizal associations with a wide range of newlinewoody plants including the members of Pinaceae, Myrataceae, Fagaceae, newlineMimosaceae, Dipterocarpaceae and Cistaceae. Although considerable heterogeneity newlineexists in terms of sporocarps, spore and isolate culture morphology, taxa within the newlinegenus Pisolithus have been widely regarded as conspecific and grouped as Pisolithus newlinetinctorius. The confusion in Pisolithus systematic is due to the fact that most species newlinewere not correctly described, was strongly synonymized or that epithet quottinctoriusquot newlinewas extensively used to different species. newlineThe development and application of molecular techniques particularly those newlinebased on the analysis of 18S rRNA genes amplified from extracted DNA, have newlinetransformed studies of fungal diversity in natural environments. Similar techniques newlinehowever have been used to characterize the ectomycorrhizal fungal diversity also. newlineMolecular techniques are based on the observation that the internal transcribed spacer newline(ITS) region of nuclear rDNA exhibits a high level of variability amongst newlineectomycorrhizal fungal species and minimal variation within the species, and thus is a newlinegood candidate for distinguishing ectomycorrhizal taxa.