The Optimization Of Nitrogen Preservation Technology Of Pleurotus Ostreatus Strain And Identification Of Preservation Effect

Liquid Nitrogen Preservation is one of the safe and effective methods of Spawn Preservation in the numerous preservation method on Edible fungi, it can keep strains for long-term. Cooling、cryoprotectant and thawing are three factors which can effect the preservation. So, we have to find the best combination of conditional processing of Liquid Nitrogen Preservation by doing a comprehensive study and identification of effect of preservation.Wanping Nol and Xinping400were studied. An orthogonal test of L33that factors were cooling、cryoprotectant and thawing was designed to study technology Liquid Nitrogen Preservation of the two strains. The identification of effect of preservation included mycelia growth index、fruiting body morphology and yield、fruiting body crude protein and soluble sugars content、esterase isozyme zymogram and SRAP molecular markers. We hope that it can help us to find the best combination of conditional processing of Liquid Nitrogen Preservation for Pleurotus ostreatus. Main conclusions are as follows:(1) The influence of mycelia growth index of Liquid Nitrogen Preservation on Wanping Nol and Xinping400were more or less the same. With none pretreatment and none cryoprotectant into liquid nitrogen, thawing at38～40℃in water bath out liquid nitrogen was the best conditions combination for mycelia growth index. Cryoprotectant and thawing way were two main influencing factors, and cooling way followed.(2) There were some change on morphological index and yield of fruiting body of the two strains after Liquid Nitrogen Preservation. The best conditions combination for the index above is AiB1C3for Wanping Nol, and cryoprotectant was main influencing factor. The best conditions combination for the index above is A3B2C3for Xinping400, and thawing way was main influencing factor.(3) The two strains, soluble protein and soluble sugar content of fruiting body have changed after Liquid Nitrogen Preservation, but it is not significant. The best conditions combination for soluble protein content of Wanping Nol was A1B2C1, cryoprotectant was main influencing factor. The best conditions combination for soluble sugar content of Wanping Nol was A1B1C3, thawing way was main influencing factor. The best conditions combination for soluble protein content of Xinping400was A3B1C1,cooling way was main influencing factor. The best conditions combination for soluble sugar content of Xinping400was A2B2C1, cryoprotectant was main influencing factor.(4) There were a few polymorphic bands in esterase isozyme zymogram and the amplification products of some primers. Polyacrylamide gel electrophoresis analysis of the two combination choosed (A1B1C3and A3B3C2for Wanping Nol, A2B3C3and A1B1C2for Xinping400) of fruiting body DNA displayed some polymorphic bands.The reason maybe that Fungi prone to mutation in environment, or some resistance genes have changed during the process of Liquid Nitrogen Preservation and the change would improve capacity of withstanding low temperature environment. The final conclusion needs some further test.(5)There were2.9enzyme polymorphic bands per treatment of Wanping Nol and4.8enzyme polymorphic bands per treatment of Xinping400. SRAR analysis displayed10polymorphic bands in Wanping Nol and23polymorphic bands in Xinping400. The proportion of polymorphic bands of the two treatment choosed of Wanping Nol is respectively4%andl.8%,and it is respectively11.7%and10.7%in Xinping400. So the effect on genetic stability of Wanping Nol is less than it is on Xinping400. There is no significant difference between the two treatments of the same strain. The high temperature type strain had more esistance than the low temperature type strain.