Cultivation methods and biology of Lentinula edodes.

In this study, the biological applications of cultivation methods related to cultivar selection, vegetative growth, and reproductive development in Lentinula edodes cultivation are briefly reviewed to clarify the current situation and inform future developments. The current cultivars widely used in the main production areas are derived from wild strains distributed in northern Asia. The most effective techniques for cultivar identification are molecular markers identified in two nuclear genome datasets and one mitochondrial genome dataset. The current stage of cultivar breeding is at the junction of Breeding 3.0 (biological breeding) and Breeding 4.0 (intelligent breeding). Plant breeder's rights and patents have different emphases on new breeding variety protection, with the former being the most utilized globally. L. edodes is mostly produced on synthetic logs filled with sawdust substrates. Hardwood sawdust comprises approximately 80% of the substrates. The vegetative growth of L. edodes on synthetic logs involves two distinct stages of mycelial colonization and browning. Mycelia mainly perform glycolysis, tricarboxylic acid cycle, and respiratory metabolism reactions to produce energy and intermediates for synthesizing the structural components of hyphae in the vegetative colonization stage. Upon stimulation by physiological and environmental pressures after colonization, mycelia trigger gluconeogenesis, autophagy, and secondary metabolism, increase metabolic flux of pentose phosphate pathway, activate the glyoxylate cycle, and accumulate melanin on the surface of logs to ensure growth and survival. Sexually competent mycelia can form hyphal knots as a result of reprogrammed hyphal branching patterns after a period of vegetative growth (which varies by cultivar) and stimulation by specific environmental factors. Under a genetically encoded developmental program, hyphal knots undergo aggregation, tissue differentiation, primordium formation, meiosis in the hymenium, stipe elongation, basidiospore production and maturation, and cap expansion to form mature fruiting bodies. Growers can achieve good fruiting body shape and high yield by regulating the number of young fruiting bodies and adjusting specific environmental factors. KEY POINTS: • Cultivar selection becomes less with the increasing technological requirement of L. edodes cultivation. • L. edodes mycelia showed different biological events in the mycelial colonization and browning stages. • Specific cultivar breading may be the next milestone in L. edodes cultivation.