Nutritional analysis and molecular characterization of hybrid mushrooms developed through intergeneric protoplast fusion between Pleurotus sajor-caju and Calocybe indica with the purpose to achieve improved strains.

Abstract

Two edible mushrooms Calocybe indica and Pleurotus sajor-caju were chosen as parent strains in this study to approach the concept of hybridization through theprotoplast fusion technique. Protoplast fusion in presence of polyethylene glycol (PEG) was conducted between the parent strains and by further double selection screening method, six somatic hybrid lines were developed. Those fruit bodies of the hybrid lines showed phenotypic resemblance with Pleurotus sajor-caju when grown on paddy straw under favorable conditions. The hybridity of the newly developed somatic hybrid strains was established by barrage reaction, morphological traits, fruitbody parameter and, inter single sequence repeat (ISSR) profiling. One-way analysis of variance (ANOVA) was used for the analysis of phenotypic data of hybrid lines and parents. Five ISSR primers were used to generate 51 amplified DNA fragments ranged between 250 and 3000bp in size in six hybrids and two parents with 90.19% polymorphism. Some of the hybrids contain some non-parental bands whichindicate that recombination might happen in thehybrid genome hence confirming the hybridity of newly developed strains. The dendrogram was created using theAverage Linkage (Between Groups) method based on ISSR profiling and genetic distance between parent-hybrids and hybrid-hybrid was analyzed by Jaccard's proximity matrix. A definite improvement in nutritional properties and biological activity was observed in the study. Due to ease in their cultivation, it can play a significant role in the rural economic development.