Breeding of New Strains of Mushroom by Basidiospore Chemical Mutagenesis

Chemical mutagenesis of basidiospores of Hypsizygus marmoreus generated new mushroom strains. The basidospores were treated with methanesulfonate methylester, an alkylating agent, to yield 400 mutant monokaryotic mycelia. Twenty fast-growing mycelia were selected and mated each other by hyphal fusion. Fifty out of the 190 matings were successful (mating rate of 26.3%), judged by the formation of clamp connections. The mutant dikaryons were cultivated to investigate their morphological and cultivation characteristics. Mutant strains No. 3 and No. 5 showed 10% and 6% increase in fruiting body production, respectively. Eight mutant strains showed delayed and reduced primordia formation, resulting in the reduced production yield with prolonged cultivation period. The number of the fruiting bodies of mutant No. 31, which displayed reduced primordial formation, was only 15, compared to the parental number of 65. Another interesting phenotype was a fruiting body with a flattened stipe and pileus. Dikaryons generated by mating with the mutant spore No. 14 produced flat fruiting bodies. Further molecular biological studies will provide details of the mechanism. This work shows that the chemical mutagenesis approach is highly utilizable in the development of mushroom strains as well as in the generation of resources for molecular genetic studies.

THE INFLUENCE OF SOME EXTERNAL FACTORS ON THE GROWTH OF HYPHAL BODY OF HYPSIZYGUS MARMOREUS / 微生物学通报

This paper is about the research on the growth of jyphal body of Hypsizygus marmoreus under the condition of different culture mediums, tempertures, pH, cardon and nitrogen sources. The result shows that Hypsizygus marmoreus can grow on various culture mediums. It grows best on the Culture medium of malt extract agar, but can not grow well on the PDA composite culture medium; the hyphal body can grow well at the temperture of 20—25℃, grows slowly at 10—30℃, but can not grow at 35℃; it can grow when pH is 5 to 8, but the best range of pH is 6.5—7.0; the nutriment assimilation is different with the different sources of carbon and nitrogen, the best carbon source is maltose, best nitrogen source is bacto-peptone.