Half-sib family structure of Fagus crenata saplings in an old-growth beech-dwarf bamboo forest
Half-sib family structure of Fagus crenata saplings in an old-growth beech-dwarf bamboo forest
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DOI：
10.1111/j.1365-294x.2005.02585.x
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发表时间：
2005-07-01
影响因子：
4.9
通讯作者：
Yamamoto, S
中科院分区：
文献类型：
--
作者：
Asuka, Y;Tomaru, N;Yamamoto, S
对山毛榉-矮化竹(Sasa spp.)利用微卫星亲子关系分析方法，在两块50×50m的样地中，对半同胞家系进行鉴定：一块有36个成虫，641株幼树，无SAA覆盖；另一块有21个成虫，61株幼树，SASA覆盖。有很大比例(分别为44.6%和75.4%)的幼树双亲出现在同一小区内，这表明授粉事件经常涉及短距离的花粉传播，这可能是由于研究种群中成虫密度较高所致。虽然几乎所有的成年人都有同父异母的家庭，但家庭中后代的数量变化很大。在没有SASA覆盖的小区中，亲本的大小显著解释了后代数量的变化，即大成虫的繁殖成功率高于小成虫。半同胞在亲本周围聚集分布，在不同的半同胞家系之间分布重叠，这可能是由于该物种的种子扩散有限和种子阴影重叠所致。不出所料，该小区的遗传结构较弱。相比之下，在SASA覆盖的小区中，半同胞稀疏分布，密度较低，遗传结构程度很弱。幼树之间半同胞家系结构和遗传结构的差异可能反映了密度的差异，这种差异应该受到与环境条件有关的更新动态的影响。
Half-sib family structure of Fagus crenata saplings was examined in an old-growth beech-dwarf bamboo (Sasa spp.) forest using microsatellite genotypes in parentage analysis to identify the half-sib families in two 50 x 50 m plots: one with 36 adults, 641 saplings and no Sasa cover, the other with 21 adults, 61 saplings and Sasa cover. For large proportions of the saplings (44.6% and 75.4%, respectively) both of their parents were found within the same plot, indicating that pollination events frequently involved short-range pollen dispersal, probably because of the high density of adults in the study population. Although almost all of the adults had half-sib families, the number of offspring in the families was highly variable. In the plot with no Sasa cover, the variation in the number of offspring was significantly explained by the size of parents, i.e. the reproductive success is higher for large adults than for small adults. The half-sibs were aggregately distributed around their parents and the distribution overlapped among different half-sib families, which may be due to the limited seed dispersal and overlapping seed shadows of this species. As expected, there was weak genetic structure in the plot. By contrast, in the plot with Sasa cover, the half-sibs were distributed sparsely with a low density, and the degree of genetic structure was very weak. The difference in the half-sib family structure and genetic structure among saplings presumably reflects the difference in density that should be affected by regeneration dynamics associated with environmental conditions.