Genetic Divergence and Cluster Analysis in Shiitake Genotypes Based on Yield Related Traits with Commercial Breeding Significance to Shorten the Production Period

Shiitake [Lentinula edodes (Berk) Pegler] mushroom (SM) has evolved into an important specialty food owing to its high nutritional content and medicinal properties. Progress on genetic improvement is limited due to a narrow genetic base. Genetic divergence and variability in 19 strains of SM were analyzed. Cultivation trials were conducted under environmentally controlled conditions suitable for growing L. edodes on synthetic logs. Mahalanobis distance (D2) and cluster analysis using Tocher’s method was used to ascertain genetic diversity. Heritability, genetic advance and components of variances were determined through variability studies. Genotypes were clustered into three major groups based on yield and yield attributing traits. The strains took an average period of 85 days from incubation to first fruiting; DMRO-388s had the shortest duration of 50 days. Days from incubation to first fruiting exhibited high heritability (97.76%) with fair genetic advance (22.83) having substantial practical utility for selection in L. edodes. Cluster analysis for shiitake improvement predicted the most promising crosses would be between DMRO-23×DMRO-388s, DMRO-34×DMRO-623, and DMRO-35×DMRO-388s. The DMRO-388s and DMRO-327 strains can be successfully cultivated on wheat straw based substrate due its quick colonization abilities. The pre-incubation period using a sawdust based cultivation system appears to shorten the cropping cycle of L. edodes which has economic implications.