Study On Quality Control Technology Of Volvariella Volvacea Spawn

The biological efficiency of Volvariella volvacea is about 20%, which is obviously lower than any other edible mushrooms. The spawn is an important factor for Volvariella volvacea production, and its quality directly relates to the yield of Volvariella volvacea. In this study, three Volvariella volvacea strains, including PY, V0023 and V-Youxi, were studied from spawn making,spawn purity and spawn activity, which were preliminarily used to establish spawn quality control technology of Volvariella volvacea. The major study results were as follows:1 Spawn MakingThis study investigated the relationships between the yield of Volvariella volvacea and culture material, moisture content, pH, incubation temperature, shelf-time of spawn. The results showed that cotton seed shell 85%, wheat bran 10%, superphosphate 1%, lime 4% and moisture content 62% had the highest yield. The most suitable moisture content of Volvariella volvacea spawn was 59% -62%. The most suitable pH of Volvariella volvacea spawn was 4% - 6% lime. Volvariella volvacea spawn growed slowly at 21℃-24℃while growed quickly at 27℃-36℃. However, Volvariella volvacea spawn cultured at 21℃-36℃had no difference in yield. With the growth of spawn shelf-time, Volvariella volvacea yield was seriously decreased. Therefore, Volvariella volvacea spawn should be used as soon as possible after its production.2 Spawn PurityThe bacteria, virus, and mycete of three Volvariella volvacea strains were detected in this study. In the detection of bacteria, bacteria with different concentration were added into the three Volvariella volvacea strains to make them form latent contamination. Then three methods, including streak plate, liquid culture and ferv.PCR were used to detect latent contamination and the sensitivity of those methods. The results showed that all the three methods could be used to detect latent contamination, and the detection limit of streak plate and ferv.PCR was 10~4 bacteria per gram of spawn while liquid culture was 10~3 bacteria per gram of spawn. In the detection of virus, virus dsRNA was detected in the positive control by means of dsRNA extraction technology and validation method while wasn,t detected in three Volvariella volvacea strains, which showed that the three Volvariella volvacea strains used in the experiment were not contaminated by virus,and this method could be used for Volvariella volvacea virus detection. Mycete was detected by plate method and the detection limit was 100 spores per gram of spawn.3 Spawn ActivitySeveral spawn activity related indexes were measured by using three Volvariella volvacea strains at different shelf-time. The results showed that the germination rate of strains, CMC enzyme activity, polyphenoloxidase activity, malondialdehyde content, the number of nucleus, the percentage of nucleated cells and the results of total RNA extraction had significant relativity among the three Volvariella volvacea shelf-time and yield, so they could be used as the activity indexes of Volvariella volvacea strains. However, the activities of amylase, protease, xylanase, acid phosphatase,peroxidase, superoxide dismutase and pH had no significant relativity among the three Volvariella volvacea shelf-time and yield. Therefore, they couldn,t be used as the activity indexes of Volvariella volvacea strains.