Genetic analysis on fruiting-time types of Lentinus edodes

自然气候条件下，在原木上生长的香菇双核菌株的结果期可分为3种类型：(1)高温型，6 ~ 8月为结果期；(2)M（中温）型，9月至次年4月果期；(3)L型（低温型），12月至次年4月结实。利用17个同核子双列杂交获得的双核子和部分杂交后代，对原木和木屑培养基在20ºC条件下的结果期类型进行了遗传分析。(1)木屑高温（20 C）下结果子的遗传控制：研究了F、双核子和3个杂交后代在木屑高温（20 C）下的结果子能力。在20℃下的结果受两个不同的遗传系统控制；一个。一个是显性单基因，另一个是由显性互补基因组成。连锁分析表明，其中一个互补基因可能与标记基因more -2或more -4松散连锁。(2)原木果期类型的遗传控制：分析了自然气候条件下F_1双核子和一个杂交后代的原木果期类型。F_1分析表明，h型结果优于其他两种，M型结果优于L型。F_1二核子（L型）的担子子代与一个测试同核子的杂交均表现为L型结果，说明L型是由控制结果时间型的位点上具有相同隐性等位基因的纯合子表达的。结果表明，木屑法可用于H型菌株的筛选试验。结果表明，木屑法可用于H型菌株的筛选试验。

The fruiting period of dikaryotic strains of Shiitake(Lentinus edodes)grown on wood logs under natural climatic conditions was divided into three types : (1)H(high-temperature)type in which fruiting occurred from June to August ; (2)M(medium-temperature)type, fruiting from September to next April ; and(3)L(low-temperature)type, fruiting from December to next April. The fruiting-time types on logs and fruiting on sawdust medium at 20 ﾟC were analyzed genetically using F, dikaryons derived from diallel crosses among seventeen homokaryons and progeny of some crosses.(1)Genetic control of fruiting at a high temperature(20 ﾟC)on sawdust medium : F, dikaryons and progeny of three crosses were examined in their ability to fruit at 20 ﾟC on sawdust medium. The fruiting at 20 ﾟC appeared to be controlled by two distinct genetic systems ; one. being dominant single gene and the other consisting of dominant complementary genes. Linkage analysis suggested that one of the complementary genes might be loosely linked to the marker gene, mor-2 or mor-4.(2)Genetic control of fruiting-time type on logs : F_1 dikaryons and progeny of a cross were analyzed for their fruiting-time types on logs under natural climatic conditions. The F_1 analysis indicated that the H-type fruiting was dominant over the other two types, and that the M type was over the L type. All the crosses between basidiospore progeny of F_1 dikaryon(L type)and a tester homokaryon exhibited the L-type fruiting, suggesting that the L type was expressed by homozygotes with identical recessive allele at the locus(loci)controlling the fruiting-time type.All of the dikaryons that exhibited the H type on logs fruited on sawdust medium at 20ﾟC, and thus the sawdust method can be used for screening tests of the H-type strains.