Lian Chunlan, Goto Susumu, Kubo Takuya, Takahashi Yasuo, Nakagawa Masahiko, Hogetsu Taizo
Asian Natural Environmental Science Center, University of Tokyo, Midori-cho 1-1-8, Nishitokyo-shi, Tokyo 188-0002, Japan.
Mol Ecol. 2008 Jun;17(12):2948-62. doi: 10.1111/j.1365-294X.2008.03802.x. Epub 2008 May 16.
Fallen logs are the main regeneration sites for Abies sachalinensis (Sachalin fir) in subboreal forests in Japan. We surveyed the spatial genetic structure of different demographic stages in a 4.29-ha natural population of A. sachalinensis. Genetic structure was significant at short distances throughout all stages in this wind-dispersed conifer. To evaluate the effects of fallen-log-dependent recruitment on demography and spatial genetic structure, we conducted parentage analysis of offspring with highly polymorphic nuclear simple sequence repeat and chloroplast simple sequence repeat markers, and developed a new hierarchical Bayesian model to estimate the effects of mother trees and fallen logs on seed dispersal and offspring recruitment. Combined application of nuclear and chloroplast simple sequence repeat markers allowed us to unambiguously identify mother trees of most offspring (> 90%). Female reproductive success was extremely skewed; a few adults produced most of the offspring on fallen logs. Limited distance of effective dispersal and recruitment was seen in the parentage analysis and modelling estimation. These recruitment characters of A. sachalinensis, with a fallen-log-dependent recruitment process, may result in significant genetic structure in early demographic stages.
倒木是日本亚寒带森林中库页冷杉（Sachalin fir）的主要更新场所。我们调查了库页冷杉一个4.29公顷自然种群中不同种群统计学阶段的空间遗传结构。在这个靠风力传播种子的针叶树种中，所有阶段在短距离内的遗传结构都很显著。为了评估依赖倒木的更新对种群统计学和空间遗传结构的影响，我们利用高度多态的核简单序列重复标记和叶绿体简单序列重复标记对后代进行了亲权分析，并开发了一种新的层次贝叶斯模型来估计母树和倒木对种子传播和后代更新的影响。核简单序列重复标记和叶绿体简单序列重复标记的联合应用使我们能够明确识别出大多数后代（>90%）的母树。雌性繁殖成功率极度偏斜；少数成年个体在倒木上产生了大部分后代。在亲权分析和模型估计中都观察到了有效传播和更新的距离有限。库页冷杉这种依赖倒木的更新过程的繁殖特征，可能会在早期种群统计学阶段导致显著的遗传结构。
