Breeding of new strains of mushroom by basidiospore chemical mutagenesis

Advances in Mechanism and Application of Molecular Breeding of Medicinal Mushrooms: A Review

With the development of molecular biology and genomics technology, mushroom breeding methods have changed from single traditional breeding to molecular breeding. Compared with traditional breeding methods, molecular breeding has the advantages of short time and high efficiency. It breaks through the restrictive factors of conventional breeding and improves the accuracy of breeding. Molecular breeding technology is gradually applied to mushroom breeding. This paper summarizes the concept of molecular breeding and the application progress of various molecular breeding technologies in mushroom breeding, in order to provide reference for future research on mushroom breeding.

Edible and medicinal fungi breeding techniques, a review: Current status and future prospects

Mushrooms of the edible and medicinal which are highly nutritious and environmentally friendly crops carry numerous medicinal benefits. For the abundant and high diversity of bioactive metabolites they possess, which are considered to be an important pool of bioresources. The efficient breeding technique is always a challenging task in mushrooms for obtaining better character strains, which are essential for developing healthy products and even consumption. This review comprehensively summarizes the breeding techniques applied to the edible and medicinal mushrooms. Including the traditional mutagenesis method, and even modern gene-editing breeding techniques, the effects of each method, and the comparison of each breeding technique are systematic illustrations. Strategies for mushroom breeding techniques in the future are also discussed in this review paper. With the ongoing sequencing of the mushroom genome, knowledge of the gene background of the strains and functions can be available for developing better markers for gene-editing breeding as CRISPR/Cas9 systems. Combine the metabolism engineering and in-silico tools analysis was the rational design of the novel strains. Modern physical mutagenesis techniques such as the ARTP and the combination of the other physical, and chemical breeding mutagens with cross-breeding techniques or the protoplasts fusion will also lead to superior strains for cultivation and pave the way for higher quality and yield.

Spatial (cap & stipe) metabolomic variations affect functional components between brown and white beech mushrooms

The beech mushrooms have customarily been revered by oriental societies for their nutritional and health benefits. We explored the mass spectrometry (MS) based spatial metabolomic variations between parts (cap and stipe) of two beech mushroom strains (brown and white). The principal component analysis (PCA) revealed their distinct primary (cap and stipe: PC1, 25.5%; strains: PC2, 12.5%) and secondary (cap and stipe: PC1, 10.3%; strains: PC2, 7.6%) metabolite patterns. The caps were rich in amino acids, fatty acids, and N-acetylglucosamine with higher protein and nitrogen contents. The stipes had abundant β-glucans, malic acid, and fructose. The discriminant secondary metabolites, especially, hypsiziprenols were higher in caps from brown strains. A fatty acid derivative, azelaic acid, was abundant in white strains (cap>stipe). We established a positive correlation for the cytotoxic activities of hypsiziprenols against ACHN cells. These spatial inter-strain metabolomic distinctions are potentially helpful for mushroom selection and improvement.

Isolation and Characterization of Monokaryotic Strains of Lentinula edodes Showing Higher Fruiting Rate and Better Fruiting Body Production

The effects of monokaryotic strains on fruiting body formation of Lentinula edodes were examined through mating and cultivation of the mated dikaryotic mycelia in sawdust medium. To accomplish this, monokaryotic strains of L. edodes were isolated from basidiospores of the commercial dikaryotic strains, Chamaram (Cham) and Sanjo701 (SJ701). A total of 703 matings (538 self-matings and 165 outcrosses) were performed, which generated 133 self-mates and 84 outcross mates. The mating rate was 25% and 50% for self-mating and outcross, respectively. The bipolarity of the outcross indicated the multi-allelic nature of the mating type genes. The mating was only dependent on the A mating type locus, while the B locus showed no effect, implying that the B locus is multi-allelic. Next, 145 selected dikaryotic mates were cultivated in sawdust medium. The self-mated dikaryotic progenies showed 51.3% and 69.5% fruiting rates for Cham and SJ701, respectively, while the fruiting rate of the outcross mates was 63.2%. The dikaryotic mates generated by mating with one of the monokaryotic strains, including A20, B2, E1, and E3, showed good fruiting performance and tended to yield high fruiting body production, while many of the monokaryotic strains failed to form fruiting bodies. Overall, these findings suggest that certain monokaryotic strains have traits enabling better mating and fruiting.

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.

Generation and Evaluation of High β-Glucan Producing Mutant Strains of Sparassis crispa

A chemical mutagenesis technique was employed for development of mutant strains of Sparassis crispa targeting the shortened cultivation time and the high β-glucan content. The homogenized mycelial fragments of S. crispa IUM4010 strain were treated with 0.2 vol% methyl methanesulfonate, an alkylating agent, yielding 199 mutant strains. Subsequent screening in terms of growth and β-glucan content yielded two mutant strains, B4 and S7. Both mutants exhibited a significant increase in β-glucan productivity by producing 0.254 and 0.236 mg soluble β-glucan/mg dry cell weight for the B4 and S7 strains, respectively, whereas the wild type strain produced 0.102 mg soluble β-glucan/mg dry cell weight. The results demonstrate the usefulness of chemical mutagenesis for generation of mutant mushroom strains.