Mycelial Propagation and Molecular Phylogenetic Relationships of Commercially Cultivated Agrocybe cylindracea based on ITS Sequences and RAPD.

Agrocybe cylindracea, known as black poplar mushroom, belongs to the family Bolbitiaceae of the order Agaricales [1]. A. cylindracea is a newly cultivated mushroom in East Asia that has become increasingly popular, due to its delicious taste and unique texture. It is cultivated mainly on low cost substrates derived from agricultural and forest wastes, barley, wheat straw, orange peel, grape stalks, rice husks and sawdust of broad leaf trees, as well as on the stumps of cottonwoods [2]. Sirand-Pugnet and Labarere [3] reported that pileus coloration, the number of spores produced per basidium and the size of basidiospores are all variable. Moreover, fruiting body size is also usually variable within a species. A. cylindracea is currently being widely studied for its medicinal properties, especially for its antioxidant, antimutagenic, antitumor, antifungal, hypercholesterolemic, and hyperlipidemic properties, its ability to decrease blood sugar [4], and its immuno-stimulating and lipid peroxidation inhibitory activities [5, 6]. Within A. cylindracea, the antifungal protein agrocybin inhibits the activity of HIV-1 reverse transcriptase [7, 8]. Therefore, this mushroom could be used to combat human diseases. Mycelium cultivation is enhanced by different environmental and nutritional factors as well as propagation of mycelia is an earlier and essential step to artificial cultivation of mushrooms [9]. Molecular phylogenetic studies have demonstrated that the internal transcribed spacer (ITS) region has generally been considered for the molecular identification of fungi at species level [10]. Among the molecular approaches, random amplification of polymorphic DNA (RAPD) is a convenient method for detecting genetic diversity [11, 12], and it was particularly successful when applied to the verification of mushroom strains from a wide range of geographical origins [13, 14]. The purpose of this study was to investigate the optimal culture conditions for the vegetative growth and molecular phylogenetic relationships of the selected strains of A. cylindracea. The various environmental and nutritional parameters were studied in these experiments.