Studies on cytoplasmic inheritance in sexual crosses and effects of cytoplasm on biological properties in Agaricus subrufescens

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06161
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40020:Wood science-related
• Research Institution: Shinshu University
• Principal Investigator: Fukuda Masaki 信州大学, 学術研究院農学系, 教授 (40208963)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: アガリクス茸 / ヒメマツタケ / 交配 / 細胞質遺伝 / ミトコンドリアDNA

Outline of Final Research Achievements

This study was carried out to determine the mode of mitochondrial inheritance for newly established heterokaryons from sexual crosses of Agaricus subrufescens, by using mtDNA RFLPs as genetic marker.
Newly established heterokaryons from the sexual crosses were found to retain mtDNA genotype from one of the parental homokaryons, suggesting that mitochondrial inheritance is principally uniparental in sexual crosses between homokaryons. Thus. one of parental strains would be selectively nuclear recipient homokaryon. On the other hand, cytoplasm-substitute strains could be constructed by using de-heterokaryotization, and their colony morphologies and mycelial growth rates were different from original strains. This suggests that biological properties of A. subrufescens are influenced by mtDNAs.
These findings obtained from this study will be useful for planning effective breeding programs of this fungus.

Free Research Field

きのこ遺伝育種学

Academic Significance and Societal Importance of the Research Achievements

細胞質がきのこの形質発現に影響を及ぼすことが示されているにも関わらず，交配に伴う細胞質の遺伝様式が明らかにされているきのこ種は少ない。また，アガリクス茸の交配株は親系統の接触部からセクター状に形成されるので，どちらの親系統の細胞質が伝達されているのかが不明瞭であった。
本菌の交配に伴う細胞質の遺伝様式は原則片親遺伝であることを示した本研究の結果から，セクター状に形成される交配株は細胞質的に均一なものとして扱えることを提示できた。また，ヒメマツタケの細胞質置換株の作出が可能なことと細胞質が表現形質に影響を及ぼすことが示されたことにより，核遺伝子のみに着目したきのこの育種に一石を投じたと言える。