Am J Bot. 1997 Dec;84(12):1675.
Recent advances in molecular biology have allowed the development of techniques to contrast spatial differentiation in nuclear and cytoplasmic genes and thus provide important data on relative levels of gene flow by pollen and seed in higher plants. In this paper, we compare the spatial structure of nuclear (allozymes) and cytoplasmic (cpDNA) genes among populations of the gynodioecious Thymus vulgaris in southern France. Based on a combination of three restriction enzymes (CfoI, EcoRV, and PstI), eight chlorotypes (combination of three restriction enzyme patterns revealed by Southern hybridization of Beta vulgaris cpDNA) were identified in the 13 studied populations. One chlorotype was particularly abundant and was detected in nearly all populations. Only one chlorotype was specific to a single population. Up to four different chlorotypes were observed in some populations. An FST of 0.238 (P < 0.002) for cpDNA haplotypes indicates spatial structure of cytoplasmic genes among the studied populations. Similar patterns were found within a single young population (CAB) structured in patches and surrounded by a continuous cover of T. vulgaris where the FST is 0.546 (P < 0.002). No significant correlation between sex and chlorotype nor between cpDNA diversity and female frequency was detected. Allozyme markers showed markedly less spatial structure (FST = 0.021 among populations and 0.019 in the CAB population, P < 0.001). This difference between cpDNA and nuclear allozyme markers suggests that pollen dispersal is more important than seed dispersal both among and within populations.
近年来，分子生物学的进展使得对比核基因和细胞质基因空间分化的技术得以发展，从而为高等植物花粉和种子的基因流相对水平提供了重要数据。在本文中，我们比较了法国南部雌雄异株的百里香（Thymus vulgaris）种群的核（等位酶）和细胞质（cpDNA）基因的空间结构。基于三种限制酶（CfoI、EcoRV 和 PstI）的组合，在 13 个研究种群中鉴定出了 8 种叶绿体类型（通过对贝塔菜（Beta vulgaris）cpDNA 的 Southern 杂交揭示的三种限制酶模式的组合）。一种叶绿体类型特别丰富，几乎在所有种群中都有发现。只有一种叶绿体类型是特定于单个种群的。在一些种群中观察到多达四种不同的叶绿体类型。cpDNA 单倍型的 FST 为 0.238（P < 0.002），表明研究种群之间细胞质基因存在空间结构。在一个由斑块组成并被百里香连续覆盖的年轻单一种群（CAB）中也发现了类似的模式，该种群的 FST 为 0.546（P < 0.002）。未检测到性与叶绿体类型之间以及 cpDNA 多样性与雌性频率之间的显著相关性。等位酶标记显示出明显较少的空间结构（种群间的 FST 为 0.021，CAB 种群的 FST 为 0.019，均 P < 0.001）。cpDNA 和核等位酶标记之间的这种差异表明，花粉传播比种子传播在种群间和种群内都更为重要。
