Establishment of axenic culture from basidiospores of an ectomycorrhizal fungus Astraeus asiaticus and A. odoratus

Abstract

Astraeus is a genus of edible ectomycorrhizal star-shaped fungus with commercial value. The inner tissue of basidiomata has previously been utilized to study the macro– and micro-cultural traits of Astraeus; though, a handful of studies have focused on basidiospores. Here we report the first pure cultural traits of Indian Astraeus asiaticus and A. odoratus obtained from basidiospores dropping/dusting method. Four distinct solid culture media namely potato dextrose agar (PDA), modified Melin–Norkrans (MMN), modified Norklan’ s C (MNC), and Yeast media (YM) were used to culture the basidiospores. After about 42 days of culture in dark at 30 °C all the cultures exhibit diffused pale–yellow pigmentation followed by radial mycelial growth with fluffy and velvety surface. Monomitic, generative hyphae, and septate clamps with paariage branching were observed which are the typical traits of the cultured mycelium. A. odoratus were successfully grown on all the four media but attempts to grow A. asiaticus on MMN, MNC, and YM were unsuccessful. The fungal culture’s identity was validated by phylogenetical approach using ITS and LSU nrDNA. The findings suggest PDA medium as the most suitable medium for culture of Astraeus and provide critical information on the culture traits that could be useful for wild mushroom cultivation thus increasing the country’s mycoprotein richness.