Plant Sciences Department, University of California, One Shields Avenue, Davis, CA 95616, USA.
Mol Ecol. 2011 Jan;20(1):46-55. doi: 10.1111/j.1365-294X.2010.04924.x. Epub 2010 Nov 11.
Indirect two-generation analysis of pollen flow has proven to be an effective alternative to exhaustive paternity analysis in numerous plant populations. In this investigation, the method is extended to an annual wild maize species, Zea mays ssp. parviglumis (Poaceae). Our analysis of mating system in parviglumis revealed high levels of outcrossing and higher biparental inbreeding than typically observed in grasses. Pollen dispersal analysis suggested low levels of long-distance dispersal. Given previous evidence for intrapopulation genetic structure in parviglumis populations, we explored the impact of cryptic population structure on estimates of mating system and pollen flow. Subpopulations inferred through spatially explicit Bayesian assignment showed markedly different values for both mating system parameters and pollen flow than the entire population. Finally, a novel method of pollen haplotype assignment revealed nonrandom mating consistent with intrapopulation structure. These results indicate parviglumis could be particularly susceptible to habitat fragmentation currently occurring throughout Mexico due to recent changes in land use.
间接两代花粉流分析已被证明是众多植物群体中详尽的亲权分析的有效替代方法。在这项研究中，该方法扩展到一年生野生玉米种， Zea mays ssp. parviglumis（禾本科）。我们对 parviglumis 交配系统的分析显示出高水平的异交和比通常在禾本科中观察到的更高的双亲近亲繁殖。花粉扩散分析表明远距离扩散水平较低。鉴于 parviglumis 种群中存在种群内遗传结构的先前证据，我们探讨了隐种群结构对交配系统和花粉流估计的影响。通过空间明确的贝叶斯分配推断的亚种群显示出与整个种群明显不同的交配系统参数和花粉流值。最后，一种新的花粉单倍型分配方法揭示了与种群内结构一致的非随机交配。这些结果表明，由于最近土地利用的变化，墨西哥各地目前发生的生境破碎化可能使 parviglumis 特别容易受到影响。
