Dynamics in genetic diversity of the cohort of clonal plants in the regeneration process.

研究了矮秆竹千岛竹大量开花死亡后更新过程中的无性系动态。竹属是一次结实的长寿克隆植物，具有大量开花的习性。本研究的目的是阐明竹种群体遗传多样性在其生活史中的长期动态.对千岛竹开花群体进行了DNA分析，阐明了群聚开花是由多个不同基因同时开花引起的.本文对21年生S.利用DNA指纹图谱法（AFLP）和挖掘法对千岛湖居群进行了研究。虽然S. kurilensis已接近恢复，种群中的基因大小变化很大。种间竞争持续加剧，导致了自疏过程。S.结果表明：1）AFLP指纹技术是克隆植物遗传动态分析的有力工具; 2）同时开花显著提高了Sasa种群的遗传多样性;（3）无性系结构在整个生活史过程中发生了广泛的变化。通过本研究，我们发现，将种群统计学研究与分子生态学技术相结合的研究方法，使得直接观察无性系植物种群的遗传动态成为可能，从而进一步加深对无性系植物种群长期动态的理解。

Clone dynamics of a dwarf bamboo, Sasa kurilensis was investigated during the regeneration process after mass flowering and death. Sasa spp. Were monocarpic long-lived clonal plants with mass flowering habits. The aim of this study is to clarify the long-term dynamics of genetic diversity in Sasa populations through their life cycles.1. We carried out DNA analysis for the flowered population of Sasa kurilensis, and clarified that mass flowering was caused by the simultaneous flowering of many different genets.2. We estimated the clone structure of the 21-year old S. kurilensis population with 1) the DNA fingerprint method (AFLP) and 2) the dig-up method. Although the population size of S. kurilensis has been nearly recovered, genet sizes in the population were widely varied. Severe inter-genet competition had continued and caused the self thinning process. S. kurilensis population has not attained stable states in 20 years after germination and it needs fairly long time to gain the stable states.We concluded that : 1) AFLP fingerprint method is a strong tool for the analysis of the genet dynamics of clonal plants : 2) The simultaneous flowering considerably enhanced the genetic diversity of Sasa population : 3) Clonal structure widely changed during the life cycle process of Sasa. Through this study, we found that the combined research method with the demographical study and molecular ecological techniques makes the direct observation of genet dynamics possible, which improve further understanding of long-term dynamics in the clonal plant populations.