Studies On Physiological Charaeteristies Effects Of Pleurotus Ostreatus Under High Temperature Stress

We use three different heat-resistent strains, such as heipingwang, Pleurotus ostreatus-99,fuyou-1,as the materials by viture of the method of plant Physiology,in order to study what high tempreture stress has effect on the phsylogical characteristics of Pleurotus ostreatus.We stress strains at 30℃,35℃and 40℃during 0.5d,ld,1.5d and 2d by cultivation and incubator.We mainly study the high tempretures’effect on the phsylogical characteristics during the period of mycelim, primordium ,fruiting and the post-harvest and 25℃is the CK. Phsylogical characteristics conclude the contents of MDA,the changes of soluble compounds, extracellular enzymes activity, Antioxidant enzymes activity and isozyme.We also discuss the effections’mechanism.The results are as the followings:1. The content of MDA is one of the important marks implying the extent damage of plasma membrane.The contents of MDA in all three strains increase at four stages under high temperature streass.With the stress time extending ,the contents of MDA are more increasing ,especially higher temperature.For most heat-resistent fuyou-1 ,the contents of MDA are obviously fewer than the heat-sensitive heipingwang and the less heat-resistent Pleurotus ostreatus-99 at different high temperatures at the stage of primordium and fruiting.It indicates that the less damage level of fuyou-1 than the heipingwang and Pleurotus ostreatus-99.2. The contents of H2O2 and O2- are Cumulative because of the high temperature stress.There are some laws of Anti- Oxygen free radicals in different strains.The activities of SOD and POD in most heat-resistent fuyou-1are higher than in less heat-resistent Pleurotus ostreatus-99,whose activities are higher than heat-sensitive heipingwang.There are some relations between the higher activity of SOD and different heat-resistent strains under three different temperatures.The high temperatures’effcts on activities of SOD and POD are most during the period of fruiting.3. The contents of soluble protein and free praline in three strains increase compared to CK’s under different high temperature stress. The accumulation of praline in the most heat-resistent fuyou-1 is more than heat-sensitive heipingwang and less heat-resistent Pleurotus ostreatus-99’s.It indicates that free praline is the potential indicator of identification which indicates the mushroom belong to the level of heat-resistence.4. The esterase isozyme changes under different high temperatures during different times in three strains,including enzyme bands weakening ,strengthening,missing or appearing of new bands.The missing and weakening of enzyme bands appear more frequently than the appearing of new bands and bands strengthening.Tha bands changing in treatment at 35℃、40℃are more than that at 30℃.The missing and increasing of bands mostly appear in these two groups.The appearance of new bands in most heat-resistent fuyou-1 is more than that in less heat-resistent Pleurotus ostreatus-99,which is more than that in heat-sensitive heipingwang.The number of bands in most heat-resistent fuyou-1 are mor e than heipingwang and Pleurotus ostreatus-99 at all stages.It indicates that changing of esterase isozyme is noe of the indicators which show the level of heat-resistence.5. High temperatures have significant effects on extracellular enzymes activity,however,not the decisive factor. The activities of laccase and carboxymethyl cellulose in three strains decrease under high temperature stress,however,increase at some stages.The changes of activities of laccase and carboxymethyl cellulose in fuyou-1 are less than that in heipingwang and Pleurotus ostreatus-99. Fuyou-1 shows the stranger heat-resistence.6. In general, the stages of extent of effections on Phsylogical characteristics in Pleurotus ostreatus under high temperature are:period of fruiting, primordium , mycelim, and the post-harvest.