Studies Of The Environmental Factors Effect On Pirmordium Formation For Pleurotus Eryngii Var.tuoliensis

Pleurotus eryngii var. tuoliensis is a famous and precious mushroom of rich nutrition and higheconomic value. Now it keeps growing in cultivation scale, but few cultured varieties and long period offruiting have been always restricting industrial development of P. eryngii var. tuoliensis. In order toshorten the breeding period and reduce work of selecting strains with short production period, theeffects of environment factors on primordia formation was carried out in the study. Meanwhile a simpleand rapid method to predict the fruiting period and identify the traits was also required.15strains of P. eryngii var. tuoliensis were used as materials in the research and were induced withlight and temperature to form primordia. The effects of running time of mycelium, types, volume, andpH of medium, poikilothermic treatment, mechanical treatments and veratric alcohol on formation ofprimordia were tested. An optimal method to induce vegetative mycelium to form primordia wasobtained which is described as follows: First, the strains were cultured at25℃for5days on30mLPDA medium of natural pH, and then were treated with alternate12h light and12h dark per day at15℃to induce primordium formation after they were cultured at4℃for3days. The mechanicaltreatments and veratric alcohol were not efficient to form primordia in the study.The length of primordia formation induced in the plates has a positive correlation with thatcultured in mushroom house. Through testing length of primordia formation induced in the plates, thelength of primordium formation could be predicted and the strains with short fruiting period can bescreened easily.15strains were divided into5classes depending on the types of primordia induced inthe plates, which are described as follows: First, the tip of mycelium formed bulbiform primordia withthick and short stipe. Second, it formed clavate primordia with thick and long sipe. The third oneformed bulbiform primordia with thick and long stipe. The fourth one formed clavate primordia withthin and long stipe. Almost all the mycelium could form primordium which is the fifth type.The differentially expressed genes between vegetative mycelium and primordia of the strain01433were studied by mRNA differential display PCR to find possible genes related to primordium formationof P. eryngii var. tuoliensis. A total of60specifically expressed cDNA fragments were generated, while32fragments among those were isolated in primordia stage.5fragments were successfully cloned andsequenced. RT-PCR analysis revealed that two candidates of the obtained fragments ware specificallytranscribed in primordia stage. A search of homology with the protein databases indicates that A320wassimilar to Non-Catalytic module family EXPN protein in Schizophyllum commune and expansin familyprotein in Laccaria bicolor, while A325showed a high sequence similarity with glycoside hydrolasefamily3in Roseiflexus castenholzi, suggesting that these genes may play important roles in promordiaformation in P. eryngii var. tuoliensis.