Isolation And Identification Of Four Auricularia Cornea From Wild Fruiting Bodies And A New Variety Breeding

Auricularia cornea is a kind of famous edible fungi,and is one of the main cultivated edible fungi in China.Shifang County is the main producing area of Auricularia cornea cultivar in Sichuan Province,and the predominant cultivar used was "Shanghai No.1".However,due to the long planting time,the resistance to pathogenic fungus is gradually weakened,and the variety degeneration is serious,resulting in a decrease in yield year by year.Therefore,it is urgent to screen a new variety of Auricularia cornea with disease resistance,high yield,and high quality.In this paper,four Auricularia spp.,named W1-W4,were isolated from wild fruiting bodies collected from different regions of Sichuan Province.The acclimation experiment was carried out from the aspects of mycelium morphology,physiological and biochemical characteristics,enzyme activity test,field agronomic traits,yield and so on,and the classification status was determined by ITS sequence identification.A new cultivar Auricularia cornea W4 was selected and bred,which was approved by Sichuan Province non-major Crop variety Identification Committee and named as "Mengding Huanger No.1",and the Identification number was “2023004”.The main results are as follows.1.Four wild Auricularia spp.fruiting bodies were collected from different regions of Sichuan Province.Their pure cultures were isolated and purified by tissue culture method,and then named W1-W4.Morphological observation showed that the tested strains had lock-like association and belonged to basidiomycetes.The phylogenetic tree was constructed by ITS sequences,the results suggested that,W1 and W4 were identified as Auricularia cornea,W2 belonged to Auricularia delicata,and W3 belonged to Auricularia villosula,respectively.2.The optimal carbon source,nitrogen source,p H value and growth temperature of each strain was analyzed by single factor test.The results showed that the optimal nitrogen source of the four tested strains was yeast powder,but the optimal carbon source was different,W1,W3 and W4 were sucrose,W2 was soluble starch.The four strains grew well at p H 6.0 to p H 7.0.The optimum growth temperature of W1,W2 and W3 was 30℃,and that of W4 was 25℃.3.The enzyme activities of 4 strains in the cultivation materia were determined.The results showed that the activities of lignin catalase and acid xylanase of Shanghai No.1 were the highest,followed by W1 and W4.Strain W1 had the highest β-glucosidase activity and strain W4 had the lowest.Strain W1 had the highest laccase activity,followed by strain W4,and strain Shanghai 1 had the lowest activity.4.By observing the growth and growth rate of mycelia of the two strains in the cultivation materia and the pre-experimental results,the mycelia growth rate of W4 was better than that of W1.Hencen,W4 was selected to carry out a field experiment,with Shanghai 1 as the reference strain.The results of strain antagonism test showed that W4 and Shanghai No.1 formed obvious antagonistic region,indicating that their physicochemical properties were significantly different.According to the requirements of DUS test guidelines,the specificity,consistency and stability of W4 were analyzed.Strain W4 and Shanghai No.1 were cultivated in two different areas for two years.The results showed that both cultivar W4 and Shanghai No.1 had similar yield,with fresh yield of 237.3 kg/200 bags for cultivar W4 and 243.8 kg/200 bags for Shanghai No.1,respectively.However,the protein content and total amino acid of cultivar W4 fruiting body were increased by 4.96% and 17.23%compared with Shanghai No.1.From the result of growth rate,the mycelium filling time and the physiological postripening time was 55 d and 15 d for cultivar W4,and was 70 d and 20 d for Shanghai No.1.Apparently,cultivar W4 had good commodity characteristics and price advantages,and could reduce the management costs effectively simultaneously.