| Because of the special climate and the lack of fine Auricularia Auricula cultivated strains which are appropriate to be cultivated in Southern China. The production of Auricularia Auricula fruit body in the south suffered series of difficulties, such as low productivity, high risky of fruitbody lysis and bag rot when the production season encountering hot and humid climate. In order to solve these problems, good wild Auricularia Auricula Strains Au053 and Au083 were screened from the local area and were acclimatized. The physiological properties of strains Au053, especialy the optimal temperature, moisture, pH and nutrition demanding was carefully investigated in order to provide the theoretical basis to establishing high effective cultivation technology for strains Au053. The difference in the aspects of nutritional physiological properties between Au053 and dominant cultivated Auricularia Auricula Strains was also studied simultaneously aimed at the mechanism of fruitbody lysis and bag rot. The results are described as following:1. By affinity test of somatic cell, the experimental results show that the Au053, Au083, Xinke No.1, Xinke No.5, Au139 are different strains (Xinke No.l, Xinke No.1 5 have affinity phenomenon, but they we proved to be different strains by some kind of enzyme activity test).2.The mycelial growth vigour, degree of thickset, and the mycelium density of Au053 strain was the best among 5 experimental Auricularia Auricula strains while the mycelium germination interval, The time for mycelium settle down was the shortest of the 5 strains, except the slowest mycelium growing speed of Au053 strain.3.Biological efficiency of comparative tests show that, the fruit body yield of Au053 is the highest of all the five strains at the same cultivation conditions. Compared with Xinke No.1, Xinke No.5, Au083 and Au139, Au053 fruit body yield increased 10.08%,8.89%,20.15%, and 22.86% respectively, the difference is significant in statistic.4.The experimental results showed that the rate of bag rot and fruitbody lysis did not happen in Au053 and Au083, while the other Auricularia Auricula strains suffered the disease badly.5. The ability for fighting infection of different Auricularia Auricula strains decreased in the order of Au053>Au083>the other strains.6. The physiological properties of Au053 strains included:the mycelium germination temperature is 18℃, the growth temperature is in the range of 14-40℃, and the optimum temperature for the mycelium growth is 25-29℃. The mycelium my grow in the culture medium with the moisture content range from 52%-68%, and the optimum moisture content is 59%-64%. The mycelium may growin the medium with pH range from 5.0-7.5, and the optimum pH value is 6.0-6.5.7.Studies on the extracellular enzyme activity in mycelial growth phase of Au053 have shown that amylase, CMC enzyme, xylanase and laccase activity were higher than the rest strains initially; amylase activity increased with the mycelial growth, the activity of it reached the top at the 20d, then it began to decreased, however, the activity of the other three kinds of enzymes had a downward trend; laccase activity changed by a very unique way when the age of mycelial growth was between 20-40d, and the activity of laccase almost disappeared, but the activity rapidly recovered and rised sharply in the age of 40d, and the activity reached nearly two times than the initial stage of growth at the age of 60d. Changes of extracellular enzyme activity had shown that starch would be prior to be used during mycelial growth phase, followed by cellulose and hemicellulose, and lignin the less, with the laccase activity recovery and a sharp rise, lignin began to be decomposed and used in the last phase of the mycelial growth, thus it could ensured its continuing supply of nutrients to maintain the vitality of mycelium and resistance to adverse environments.8.By investigation into the extracellular enzyme activity and their changes during the mycelium growth of Au053 and the dominant Auricularia Auricula cultivated strains. We Analyze the differences of their nutritional physiological properties. The mechanism of mycelium germination, mycelium settle down, and bag rot and fruitbody lysis was discussed.
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