Studies on the relationship between genetic diversity within the fungus that specifically occur on Fagus crenata supule and its host distribution.

为了寻找影响真菌分布的主要因素，比较了日本大面积地区毛毛豆上长柄毛盖菌（Dasyscyphella longistipitata）（透明盖菌科，阳毛菌目，双囊菌门，子囊菌门）的ITS序列多样性。在每个采样点每隔5 m采集5 ~ 20个杯状体，获得单孢子分离物。从12个地点获得的120个分离物中检测到38种单倍型，其中H12单倍型占分离物总数的43%。此外，H28（15%）和H10（10%）是三种主要的单倍型。这三个单倍型被放置在内部分支的单倍型网络的基础上统计简约。巢式进化枝分析没有显示地理隔离。分子方差分析表明，该群体的遗传多样性主要来源于群体内的遗传多样性。遗传距离与地理距离没有相关性，与宿主的系统发育分组也没有相关性。这些事实表明，整个长柄山核桃种群形成了一个大的连续统。然而，在日本的西南地区和东北地区的遗传多样性较高。这种遗传分布格局表明，日本西南部的日本小卷蛾种群起源于冰川期的祖先种群，遗传多样性较高，随后随着寄主的扩张而沿着不断扩张，日本中部由于寄主的灭绝而遗传多样性下降，而日本东北部由于寄主的持续分布而保持了多样性。

To search for major factors that affected fungal distribution, ITS sequence diversity of Dasyscyphella longistipitata(Hyaloscyphaceae, Helotiales, Disomyoate, Ascomycota) that occur on Fagus crenata cupulus obtained from wide areas in Japan were compared. Five to 20 cupules were collected every 5m apart at each sampling site, and single-spored isolates were obtained. In 120 isolates obtained from 12 sites, 38 haplotypes were detected, and the haplotype H12(43% of the total isolates) was detected from all the populations. In addition, H28(15%) and H10(10%) consisted of the three major haplotypes. These three haplotypes were placed in inner clades in the haplotype network based on statistical parsimony. Nested clade analysis did not indicate geographic isolation. Analysis of molecular variance attributed the genetic diversity for the diversity within the population. Genetic distance was not found to be correlated with geological distance, and no relationship was found with the phylogenetic grouping of the host. These facts suggested the whole the populations of D.longistipitata Japan form a large continuum. However, genetic diversity was higher in south-western areas and north eastern areas in Japan. This genetic distribution pattern suggests that the current population initiated from the ancestral population in the glacier period with high genetic diversity in south-western Japan, followed by the continuous expansion along with the host expansion, decrease of the genetic diversity in the middle Japan due to the extinction of the host, while keeping diversity due to continuous distribution of the host in the north-east Japan.