Identification of Eight High Yielding Strains via Morpho-Molecular Characterization of Thirty-Three Wild Strains of Calocybe indica.

Calocybe indica, generally referred as milky mushroom, is one of the edible mushroom species suitable for cultivation in the tropical and sub-tropical regions of the world. However, lack of potential high yielding strains has limited its wider adaptability. To overcome this limitation, in this study, the germplasms of C. indica from different geographical regions of India were characterized based on their morphological, molecular and agronomical attributes. Internal transcribed spacers (ITS1 and ITS4)-based PCR amplification, sequencing and nucleotide analysis confirmed the identity of all the studied strains as C. indica. Further, evaluation of these strains for morphological and yield parameters led to the identification of eight high yielding strains in comparison to the control (DMRO-302). Moreover, genetic diversity analysis of these thirty-three strains was performed using ten sequence-related amplified polymorphism (SRAP) markers/combinations. The Unweighted Pair-group Method with Arithmetic Averages (UPGMA)-based phylogenetic analysis categorized the thirty-three strains along with the control into three clusters. Cluster I possesses the maximum number of strains. Among the high yielding strains, high antioxidant activity and phenol content was recorded in DMRO-54, while maximum protein content was observed in DMRO-202 and DMRO-299 as compared with the control strain. The outcome of this study will help the mushroom breeders and growers in commercializing C. indica.

Identification of Key Regulatory Pathways of Basidiocarp Formation in Pleurotus spp. Using Modeling, Simulation and System Biology Studies.

Pleurotus (Oyster mushroom) is an important cultivated edible mushroom across the world. It has several therapeutic effects as it contains various useful bio-molecules. The cultivation and crop management of these basidiomycete fungi depends on many extrinsic and intrinsic factors such as substrate composition, growing environment, enzymatic properties, and the genetic makeup, etc. Moreover, for efficient crop production, a comprehensive understanding of the fundamental properties viz. intrinsic-extrinsic factors and genotype-environment interaction analysis is required. The present study explores the basidiocarp formation biology in Pleurotus mushroom using an in silico response to the environmental factors and involvement of the major regulatory genes. The predictive model developed in this study indicates involvement of the key regulatory pathways in the pinhead to fruit body development process. Notably, the major regulatory pathways involved in the conversion of mycelium aggregation to pinhead formation and White Collar protein (PoWC1) binding flavin-chromophore (FAD) to activate respiratory enzymes. Overall, cell differentiation and higher expression of respiratory enzymes are the two important steps for basidiocarp formation. PoWC1 and pofst genes were participate in the structural changes process. Besides this, the PoWC1 gene is also involved in the respiratory requirement, while the OLYA6 gene is the triggering point of fruiting. The findings of the present study could be utilized to understand the detailed mechanism associated with the basidiocarp formation and to cultivate mushrooms at a sustainable level.

Biochemical Profiling and Cultivation of Medicinal Fungus Isaria cicadae (Ascomycetes) from India.

Isaria cicadae is an entomopathogenic fungus possessing several therapeutic properties and has a potential role in traditional Chinese medicine. The present study was designed to describe the taxonomic details of a new isolate of I. cicadae collected from the Northern Himalayas of India and to study its vegetative and reproductive growth responses under in vitro conditions. Proximate composition, biochemical profiling, and radical scavenging activities were studied to establish the bioactivity of the isolate. Micromorphological characteristics of conidia and conidiophore formation were studied using scanning electron microscopy. The optimum temperature and pH for mycelial growth was 25°C and 7.0, respectively. Pinhead initiation was observed at day 10 after inoculation, but the fully developed, branched, and coral to club-shaped fruiting bodies could be observed after 30 days of inoculation. Proximate analysis indicated that carbohydrates are the major constituents (50.2%) of the fruit bodies, along with a lower quantity of protein (4.46%), crude fat (6.4%), and crude fiber (1.55%). Vitamin D content of I. cicadae was 3,605.84 IU/g. Radical scavenging activity based on the DPPT (1,1-diphenyl-2-picrylhydrazyl) assay was 21.2%. ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid] and potassium ferricyanide reducing activity were quite high, at around 93% and 99.3%, respectively. The findings of this study provide insight into the biochemical constituents of I. cicadae and its cultivation practices for further exploitation of this mushroom at a larger scale.

Nutritional and Biochemical Characterization of Panus lecomtei Mushroom (Agaricomycetes) from India and Its Cultivation.

Panus lecomtei is emerging as an edible mushroom found worldwide and particularly in the Northern Hemisphere. The mushroom contains a substantial amount of useful nutritional and medicinal compounds. In the present study, we have examined a specimen of P. lecomtei submitted to the ICAR-Directorate of Mushroom Research gene bank. The specimen was examined for taxonomical characters using classical and molecular tools. Attempts were made for cultivation of this mushroom under controlled conditions using sawdust-based substrate. The specimen was characterized by its purplish fruiting body having coarse, rigid, dense hairs on the cap, pubescent stipe, and abundant metuloids. Molecular identification through conserved ITS region was done and the sequence was deposited in NCBI GenBank under accession number MN332200. Nutritional profiling and biochemical analysis showed that the mushroom contained high carbohydrate but low fat contents. The mushroom showed the presence of phenolics, ß-carotene, and lycopene. The analysis also showed substantial antioxidant properties in the mushroom. The findings presented herein point out that P. lecomtei can be used as a potential edible mushroom for diversification of mushroom production in India.

Genetic improvement in Pleurotus (oyster mushroom): a review.

Pleurotus is an important genus comprising several edible species of great commercial significance. These species are grown all across the world. The production areas of Pleurotus mainly belong to the Asian part and are gaining wide popularity across the globe owing to their promising nutritional gains. The demand for improved strains with high productivity has also been rising. The genetic improvement in Pleurotus started with a simple selection technique, which later utilized hybridization (intraspecific, interspecific and intergeneric) and mutation breeding. The traits such as productivity, sporelessness and quality improvement are important objectives on which most of the works have been done so far. However, new generation approaches such as molecular breeding, genetic transformation and genome editing techniques also added pace to the present improvement process. Hitherto, seven species of Pleurotus have been sequenced and a sizable data has been generated that can be used in further breeding programs. This paper discusses and summarizes various research findings on genetic improvement of Pleurotus and gives an outlook for future breeding programs.