侧耳属食用菌高温胁迫条件优化研究

Optimization of heat stress for Pleurotus spp. cultivation

侧耳属真菌是我国最大规模栽培的食用菌,主要是糙皮侧耳Pleurotus ostreatus和白黄侧耳P.cornucopiae。高温是影响侧耳产量和质量的重要因子之一,确定高温胁迫条件是开展高温胁迫机制研究的方法学基础。以糙皮侧耳和白黄侧耳的11个菌株为材料,以硫代巴比妥酸反应产物(thiobarbituric acid reactive substances,TBARS)含量为主要生理指标,结合菌丝形态和生长等微生物学参数,开展了双核体菌丝高温胁迫条件的研究,包括胁迫的适宜温度、时间和菌龄等。结果表明,所有供试材料,高温胁迫后菌丝体内TBARS含量在28–40℃、0–48h范围内与温度和时间呈正相关,与之后的恢复生长率呈负相关,高温胁迫后菌丝体内TBARS含量和之后的恢复生长能力均与自身菌丝体生长和子实体形成的适宜温度无关。TBARS含量可作为菌丝高温胁迫生理研究条件确定的指标。与植物的最适温度加10℃不同,基于TBARS含量的糙皮侧耳和白黄侧耳高温胁迫研究条件应为DifcoTM Potato Dextrose Agar培养基,菌丝培养3d,最适温度加12℃,高温胁迫处理48h。

Oyster mushroom is widely cultivated in China, and Pleurotus ostreatus and P. cornucopiae are the two representative species. Heat stress affects the quality and productivity of oyster mushroom. Determination of the stress level is the key to the research on the mechanism of heat stress. Heat stress condition includes different elements, such as stress temperature, stress duration and the age of hyphae. Based on TBARS content as the main physiological indexes, combining microbiologica parameters such as mycelium morphology and the growth of 11 strains, the level of heat stress conditions for P. ostreatus and Pcornucopiae was studied. Results showed that thiobarbituric acid reactive substances （BARS） content in mycelium under heat stress were positively correlated with temperature （28℃ to 40℃） and duration （Oh to 48h）, but negatively correlated with the recovery rate of mycelium growth. However, TBARS content and recovery rate after heat stress were not related with the natura temperature of mycelium growth and fruiting body formation. TBARS content can be used as a physiological index determining the conditions of heat stress for the mycelium of oyster mushroom. The heat stress conditions are optimized by using 3-day-old mycelium as the material, 12℃ higher than the optimal growth temperature, while the heat level for plant is 10℃ higher than the optimal growth temperature