Optimization of basidiospore germination and morphogenesis of Pleurotus ostreatus and Oudemansiella canarii

Abstract

Mushrooms are valued globally for their nutritional, medicinal, and ecological significance. Beyond their rich content of vitamins, proteins, and minerals, these macroscopic fungi are vital decomposers, playing a critical role in nutrient cycling and even influencing rainfall in forest ecosystems through their spores. This study investigated the optimal conditions for basidiospore germination. It documents the comprehensive developmental stages of two economically important edible mushroom species, Pleurotus ostreatus (CLSU strain), and Oudemansiella canarii (OCNu strain), aiming to enhance cultivation practices and deepen our understanding of their life cycles. Basidiospores were collected from mature fruiting bodies and suspended in sterile distilled water. The study evaluated the influence of various broth media (coconut water, corn grit, potato sucrose, potato dextrose), pH levels (4-8), illumination conditions (lighted, dark, alternating light/dark), and temperatures (refrigerated, air-conditioned, room temperature) on spore germination. Results showed that coconut water was the most suitable culture medium for both mushrooms. For O. canarii, optimal germination occurred at pH 6, while P. ostreatus favored pH 7; both were incubated under alternating light/dark conditions at room temperature (33–35 °C). The developmental processes from basidiospore to mature basidiocarp were photo-documented, revealing distinct vegetative (swelling, germ tube formation, elongation, septation, branching, and mycelial thickening) and reproductive stages (primordia, pinhead, stipe elongation, and pileus expansion). Understanding these optimal conditions and developmental stages is crucial for developing effective, sustainable cultural management practices that maximize mushroom biomass production and improve the quality and yield of P. ostreatus and O. canarii in cultivation.