DEVELOPMENT OF THE IMPROVED STRAINS OF OUDEMANSIELLA APARLOSARCA (GILLY MUSHROOM) FOR INDUSTRIAL CULTIVATION 

Oudemansiella aparlosarca is an edible mushroom possessing medicinal and health  benefits. Although there are studies on the cultivation of O. aparlosarca, it has come to light  that, only few studies have focused on its genetics and life cycle. Therefore, the main  objective of this study was to identify the nuclear conditions of basidiospores and homokaryotic and heterokaryotic hyphal cells, basidium morphology, and to develop high quality strains through cross breeding with desirable traits and characteristics for the industrial production of O. aparlosarca. Two parental strains, strain-55 and strain-81, were used. Staining of basidiospores and hyphal cells in the apical region was performed. The selected homokaryons were mated each other to develop new hybrid strains. Molecular markers were designed according to the mating type genes. Length, area, and the number of nuclei in basidia were measured. The nuclear states of non-nucleate, mono-nucleate, bi nucleate, and multi-nucleate were observed. Bi-nucleate spores predominated in both parental strains, while non-nucleate spores were the least common. Non-nucleate spores had the smallest diameter, measuring 11.52 μm in parental strain-81 and 12.15 μm in parental  strain-55, while multi-nucleate spores had the maximum diameter, measuring 14.78 μm in  both parental strains. Both homokaryotic and heterokaryotic strains were identified in isolated single spores. Bi-nucleate cells were predominantly present in heterokaryotic hyphal  cells, and multinucleated cells were predominant in homokaryotic hyphal cells. The hybrids  K26XG6, K24XG37, and K17XG10 exhibited better cultivation characteristics, and fruiting  morphology than the parental strain. Primer No. 2 and 6 can be employed as a mating molecular marker to analyze the mating-type gene of O. aparlosarca. A gradual increase in  basidia length and area was observed, and tetra-nuclear basidia were the most abundant. It  was concluded that O. aparlosarca contains homokaryotic and heterokaryotic basidiospores,  indicating an amphithallic life cycle. The observed bi-nucleate spores could be the result of post-meiotic mitosis. The bi-polar mating system (A1A2) has existed in O. aparlosarca. The sexual life cycle was systematically analyzed in this study. 

KEYWORDS: Amphithallic life cycle, bi-nucleate, bi-polar mating system, cross breeding, Oudemansiella aparlosarca, post-meiotic mitosis.