Chung Jae Min, Lee Byeung Cheun, Kim Jin Seok, Park Chong-Wook, Chung Mi Yoon, Chung Myong Gi
Division of Specimen and Genetic Resources, National Arboretum, Korea Forest Service, Gyeonggi Province, 487-821, Republic of Korea.
Ann Bot. 2006 Jul;98(1):165-73. doi: 10.1093/aob/mcl083. Epub 2006 May 4.
For rare endemics or endangered plant species that reproduce both sexually and vegetatively it is critical to understand the extent of clonality because assessment of clonal extent and distribution has important ecological and evolutionary consequences with conservation implications. A survey was undertaken to understand clonal effects on fine-scale genetic structure (FSGS) in two populations (one from a disturbed and the other from an undisturbed locality) of Echinosophora koreensis, an endangered small shrub belonging to a monotypic genus in central Korea that reproduces both sexually and vegetatively via rhizomes.
Using inter-simple sequence repeats (ISSRs) as genetic markers, the spatial distribution of individuals was evaluated using Ripley's L(d)-statistics and quantified the spatial scale of clonal spread and spatial distribution of ISSR genotypes using spatial autocorrelation analysis techniques (join-count statistics and kinship coefficient, F(ij)) for total samples and samples excluding clones.
A high degree of differentiation between populations was observed (phi(ST(g)) = 0.184, P < 0.001). Ripley's L(d)-statistics revealed a near random distribution of individuals in a disturbed population, whereas significant aggregation of individuals was found in an undisturbed site. The join-count statistics revealed that most clones significantly aggregate at < or = 6-m interplant distance. The Sp statistic reflecting patterns of correlograms revealed a strong pattern of FSGS for all four data sets (Sp = 0.072-0.154), but these patterns were not significantly different from each other. At small interplant distances (< or = 2 m), however, jackknifed 95% CIs revealed that the total samples exhibited significantly higher F(ij) values than the same samples excluding clones.
The strong FSGS from genets is consistent with two biological and ecological traits of E. koreensis: bee-pollination and limited seed dispersal. Furthermore, potential clone mates over repeated generations would contribute to the observed high F(ij) values among genets at short distance. To ensure long-term ex situ genetic variability of the endangered E. koreensis, individuals located at distances of 10-12 m should be collected across entire populations of E. koreensis.
对于有性繁殖和无性繁殖兼有的珍稀地方特有或濒危植物物种而言，了解克隆性程度至关重要，因为评估克隆程度和分布具有重要的生态和进化意义，对保护工作也有影响。开展了一项调查，以了解克隆对朝鲜刺萼参两个种群（一个来自受干扰地区，另一个来自未受干扰地区）微尺度遗传结构（FSGS）的影响。朝鲜刺萼参是韩国中部一个单型属的濒危小灌木，通过根状茎进行有性繁殖和无性繁殖。
使用简单序列重复区间（ISSR）作为遗传标记，利用Ripley's L(d)统计量评估个体的空间分布，并使用空间自相关分析技术（联合计数统计和亲属系数F(ij)）对总样本和排除克隆的样本量化克隆传播的空间尺度和ISSR基因型的空间分布。
观察到种群间存在高度分化（phi(ST(g)) = 0.184，P < 0.001）。Ripley's L(d)统计量显示，受干扰种群中的个体分布近乎随机，而在未受干扰的地点发现个体有显著聚集。联合计数统计显示，大多数克隆在植株间距离≤6米处显著聚集。反映相关图模式的Sp统计量显示，所有四个数据集均有强烈的FSGS模式（Sp = 0.072 - 0.154），但这些模式彼此之间无显著差异。然而，在较小的植株间距离（≤2米）时，刀切法95%置信区间显示，总样本的F(ij)值显著高于排除克隆的相同样本。
来自基因的强烈FSGS与朝鲜刺萼参的两个生物学和生态学特征一致：蜜蜂授粉和有限的种子传播。此外，经过多代的潜在克隆配偶会导致在短距离内基因间观察到较高的F(ij)值。为确保濒危朝鲜刺萼参的长期迁地遗传变异性，应在朝鲜刺萼参的整个种群中采集距离为10 - 12米的个体。
