The Effect of Low Temperature Applied During Carpophore Formation on The Development and Nutritional Content of Oyster Mushrooms (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm (1871) and P. citrinopileatus Singer)

Consumption of oyster mushrooms, which is a rich food source, has increased in every region of the world. Especially in recent years, there has been an increase in the production and consumption of foods with high nutritional value such as oyster mushrooms. However, the importance of climatic values is very important in mushroom production. In the present study, the growth and nutrient content of two oyster mushrooms [Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm (1871) (gray oyster mushroom), P. citrinopileatus Singer (yellow oyster mushroom)] were investigated under two different temperatures (22 ⁰C and 10 ⁰C after carpophore formation) to see how mushroom would be affected under low temperature conditions. The study, which was established with 2-liter ready-made mushroom production kits, was designed according to the completely randomized experimental plot design with three replications each consisting four kits. Carpophore area and thickness, potassium (K), calcium (Ca) and magnesium (Mg) contents, and the changes in catalase (CAT) and Ascorbate peroxidase (APX) enzyme activities were investigated in both oyster mushroom species under two temperatures. There were various effects of low temperature and mushroom species on the studied traits. The oyster mushrooms exposed to low temperature had a significant effect on the carpophore area and thickness. Moreover, there was a significant difference between the carpophore areas of two oyster mushroom species at low temperature and between the carpophore thicknesses of two oyster mushroom species at control temperature. The effect of low temperature on the change in K content was found to be significant in both oyster mushrooms. Gray oyster mushroom had significantly higher (17.54%) K content than the yellow oyster mushroom at control temperature, while yellow oyster mushroom had significantly lower (17.49%) Mg content at low temperature compared to control temperature. In low temperature environment condition, the CAT activity increased by 5.7 times in gray oyster mushroom and 5.0 in yellow oyster mushroom. Moreover, The APX activities of mushrooms at low temperature increased by 8.1 times in gray oyster mushroom and 7.5 times in yellow oyster mushroom. Moreover, the yellow oyster mushroom had significantly (p<0.01) higher CAT and APX contents (0.57 and 1.43 times, respectively) than the gray oyster mushroom at low temperature.