Elucidation of the mating system and development of breeding technology in Agaricus blazei

开发具有高子实体生产力等优良特性的姬松茸新品种，对促进商品化生产具有重要意义。然而，关于A.blazei品种的发育的信息很少。因此，对白纹伊蚊的基础遗传学研究就显得格外重要。本研究旨在研究异核菌株与其单孢子分离物(SSI)之间的遗传差异，并根据AFLP图谱进行SSI配对以确认杂种形成。此外，原生质体再生方法对孢子萌发和脱异核化的刺激条件，单株SSIS的AFLP(扩增片段长度多态性)条带总数明显少于其亲本菌株(异核菌株)，表明利用AFLP图谱可以区分异核菌株及其SSIS。亲本菌株的许多AFLP条带在SSI中以1：1的比例分离，这表明SSI是同核的。虽然仅凭SSI间配对菌落的菌落形态很难确定杂种的形成，但AFLP谱带是确认SSI间杂交成功的合适遗传标记。研究了几种因素对发芽灵芝担孢子萌发的影响：以树皮堆肥提取液为基本培养基，添加琥珀酸，与发芽灵异核菌活菌丝体共培养，培养前对担孢子进行热处理，可有效地促进担孢子萌发。此外，原生质体再生方法似乎对去异核化也是有用的。

The development of Agaricus blazei cultivars with superior properties such as high fruiting body productivity will be very important for promoting commercial production. There is, however, little information available about the development of A.blazei cultivars. Therefore, fundamental genetic research on A.blazei takes on additional importance. This study was performed to examine genetic differences between heterokaryotic strains and their single-spore isolates (SSIs) and to confirm hybrid formation by pairing of SSIs based on AFLP profiles. Furthermore, stimulation conditions of the spore germination and de-heterokaryotization by the protoplast regeneration method.The total number of AFLP (Amplified Fragment Length Polymorphism) bands from individual SSIs was clearly less than those from their parental strains (heterokaryotic strains), indicating that the discrimination of heterokaryotic strain and its SSIs was possible by the AFLP profile. Many of polymorphic AFLP bands from the parental strains segregated in SSIs at a ratio of 1 : 1, suggesting that the SSIs are homokaryotic. Although it was very difficult to confirm hybrid formation by only colony morphologies of the isolates from paired colonies between SSIs, AFLP bands are suitable genetic makers for the confirmation of successful crosses between SSIs in A.blazei. Effects of several factors on basidiospore germination of A.blazei were examined : bark compost-extracts medium as basal medium, addition of succinic acid to medium, co-culture with living mycelia of A.blazei heterokaryotic strain, and heat treatment of basidiospores before culturing would be effective to stimulate spore germination. In addition, protoplast regeneration method seemed to be useful for de-heterokaryotization in A.blazei