Morphological and molecular characterization of Pleurotus pulmonarius hybrids with improved sporophore features and higher biological efficacy

Abstract

To improve the sporophore characteristics and production yield of Pleurotus pulmonarius by interspecies hybridization between monokaryotic cultures of P. pulmonarius and P. citrinopileatus, a total of a hundred possible pairings were done. Five hybrids were obtained producing sporophores with morphological characteristics dominant to those of P. pulmonarius. DNA analysis confirmed the high genetic affiliation of the hybrids with P. pulmonarius generating a bootstrap value of 99%. Among the hybrids, P19xC5 strain exhibited good traits such as higher mycelial growth rate, thicker mycelium density as well as generating sporophores with fleshier texture and bigger pileus. Further analysis by spawning showed that it had faster growth rate at 8.7 mm/day as opposed to 8.2 and 7.7 mm/day for P. pulmonarius and P. citrinopileatus, respectively. It generated a higher sporophores yield (182.97 g) and biological efficiency (130.19%) which was approximately twice that of the parental strains. Its sporophore was found to contain lower spore density, a criteria favourable for the health and work conditions of farm workers. The good features imposed by the hybrid P19xC5 may indicate its better adoption in the mushroom growing industry and greater commercialization value.