A novel breeding strategy for new strains of Hypsizygus marmoreus and Grifola frondosa based on ligninolytic enzymes.

A novel breeding strategy for new strains of Hypsizygus marmoreus and Grifola frondosa using ligninolytic enzymes as markers was evaluated with the detection and analysis of activities and composition of 15 edible fungi. The results showed that the activity and composition of ligninolytic enzyme system varied in response to changes of fungal strains. By analyzing the growth rate of mycelia and their ability to produce ligninolytic enzymes, H. marmoreus and P. geesteranus, G. frondosa and P. sajor-caju were screened for further study. Three colonies of 26 regenerated colonies of H. marmoreus and P. geesteranus protoplast fusion and one colony of 48 regenerated colonies of G. frondosa and P. sajor-caju were selected respectively. At the same time, these four strains were identified using RAPD and ISSR molecular markers. The results showed that the strains HM5G1 and PS7F1 are new strains and have low similarity to parental strains H. marmoreus and G. frondosa. These results are supported by the results of antagonism tests. These two fusants were significantly higher in their ligninolytic enzyme activity than H. marmoreus and G. frondosa. The growth rates of strains HM5G1and PS7F1 were also noticeably higher than those of H. marmoreus and G. frondosa, by 1.36 and 1.5 times respectively. The biological efficiency of the strain HM5G1 was 11.5% higher than that of the parental strain H. marmoreus. This work suggests that it is an efficient way of breeding new strains to use the decolorization of ligninolytic enzymes as a preliminary screening marker.