Investigation on the factors for depression of propagation ability in an isolated beech population-Analysis of the loci for inbreeding depression maintained within a meta-population-

山毛榉孤立种群繁殖能力下降的因素调查-集合种群内近交衰退位点分析-

• 批准号: 15380101
• 负责人: MUKAI Yuzuru
• 金额: $ 10.24万
• 依托单位: Gifu University (2004-2005)Shizuoka University (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15380101/
• 关键词: Fagus crenata; inbreeding depression; linkage map; meta-population; genetic structure; gene flow; molecular markers; 人工交雑; マイクロサテライトマーカー; 花粉生産量; 開花率; 局所個体群; マイクロサテライトDNA

Self and cross pollination were performed with a mother tree grown in a natural population of Fagus crenata. Although the percentages of sound acorns produced by self pollination were remarkably low (0 to 16.2%), those produced by cross pollination were higher and varied with the pollen parent (41 to 95%). The results suggest Fagus crenata is self-incompatible.Genotypes of the parental trees and F_1 progenies were determined by AFLP and SSR markers, and linkage maps for male (140 markers,12 linkage groups,1037 cM) and female (206 markers,13 linkage groups,1096 cM) were constructed. The acorn-soundness for cross pollination was correlated with the genome wide similarities between mother and the pollen parents, indicating the existence of bi-parental inbreeding depression. To examine the number and repertories of the alleles related to inbreeding depression, segregation distortion in F_1 progenies generated from the pollination with the different fathers was examined at the 87 loci selected from whole genome.Fifteen loci represented significant segregation distortion. In the three loci, segregation distortion was observed in common with two pedigrees. In the five loci, segregation distortion was observed in common with three different pedigrees. These results indicate that the individuals grown in the local population shared alleles related to inbreeding depressionPollen mediated gene flow was assessed using four SSR markers. The majority (92%) of pollen mediated gene flow was revealed to be limited within the local population. Although beech shows self incompatibility and has some loci related to inbreeding depression and the week spatial genetic structure was formed within the local population, correlation between relatedness and pollen parent-contribution was very week. Since distances between the parents, as well as the size of pollen parents affected on the paternal contribution, pollen productivity might be important factor for acorn productivity.

以毛茛自然种群中生长的母树为母本进行自花授粉和异花授粉。自花授粉结实率极低（0 ~ 16.2%），异花授粉结实率较高，且因花粉亲本不同而异（41 ~ 95%）。利用AFLP和SSR标记对毛毛豆亲本和F_1代进行基因型分析，构建了毛豆雄性（140个标记，12个连锁群，1037 cM）和雌性（206个标记，13个连锁群，1096 cM）的连锁图谱。异花授粉的橡子结实性与母本和花粉亲本之间的基因组相似性相关，表明双亲近交衰退的存在。为了研究与近交衰退相关的等位基因的数量和种类，在从全基因组中筛选出的87个位点上，对不同父本授粉产生的F_1后代进行了偏分离分析，发现有15个位点表现出明显的偏分离。在这三个位点上，两个家系都出现了偏分离现象。在这5个位点上，3个不同的家系都出现了偏分离现象。这些结果表明，在当地群体中生长的个体具有与近交衰退相关的等位基因。大多数（92%）的花粉介导的基因流被发现是有限的本地人口。虽然山毛榉表现出自交不亲和性，并存在与近交衰退相关的位点，在当地居群内形成了弱空间遗传结构，但其亲缘关系与花粉亲本贡献的相关性很弱。由于双亲间的距离以及花粉亲本的大小影响父本的贡献，花粉生产力可能是影响橡子生产力的重要因素。

项目成果

Pollen-mediated gene flow in a small, fragmented natural population of Fagus crenata Blume

花粉介导的小而分散的自然水青冈种群中的基因流

• 发表时间: 2007
• 期刊: Canadian Journal of Botany (in press)
• 作者: So Hanaoka;Jungo Yuzurihara;Yamashita Asuka;Nobuhiro Tomaru;YoshihikoTsumura;Yoshitaka Kakubari;Yuzuru Mukai
• 通讯作者: Yuzuru Mukai