Abstract: In order to screen high-quality Morchella esculenta strains with stable production capacity, the single-gene and multi-gene combination methods were used to identify six wild morel strains collected in this study. Moreover, the activity of antioxidant enzymes such as catalase, polyphenol oxidase, peroxidase, and the content of malondialdehyde (MDA) of mycelia in liquid culture conditions were analyzed. The expected strain suitable for cultivation was screened out by using the subordinate function method. The results showed that all the six wild morels collected belonged to Morchella sextelata, and the black morel (Elata Clade) group. The morphological characteristics of mycelium for Morchella esculenta changed from white to yellowish, the mycelium arranged closely, the end of mycelium blunt, the thickness of mycelium was uneven and a part of surfaces were distributed with globules, and the growth rate of mycelium was in the range of 0.40-0.45mm/d. The results of mating type genes showed that three strains LM1, LM3, and LM4 contained two mating type genes, MAT1-1 and MAT1-2, which were capable of sexual reproduction. In particular, strain LM4 had significantly higher PPO, POD, CAT, and TTC-dehydrogenase enzyme activities than the others two strains, accompanied by the lowest MDA content. Combined with the affiliation function analysis, the average affiliation function of strain LM4 was 0.9647, which is a high-quality Morchella esculenta with high vigor and can be used as a cultivation test strain.

Key words: Morchella esculenta, strain identification, mating type genes, biomass, antioxidant enzyme activity