短枝木麻黄花粉散布对生殖成功和子代适应性的影响

花粉是植物主要的基因流载体，其散布的距离和模式不仅能改变植物居群的遗传结构与多样性，还会影响植物的生殖成功和子代适应性。文献表明，国内外主要在居群尺度上对天然分布植物开展花粉散布研究，在外来树种人工林的个体水平上对花粉散布研究还鲜有报道。本项目以短枝木麻黄为研究对象，在人工林内采集雌株的种子和该雌株周围雄株的叶样，同时采集雄株的叶样和该雄株周围雌株的种子，应用基于SSR分子标记的父本分析技术确定种子的父本来源，揭示短枝木麻黄在自由授粉条件下的花粉散布距离与模式；在苗圃中，以开花的嫁接盆栽雄株为中心，在不同方向和距离放置开花的嫁接盆栽雌株和设置花粉捕捉器，结合气候因子观测数据，研究花粉的散布模式、不同距离和方向的花粉密度和花粉限制值等，探讨它们对生殖成功和子代适应性的影响。研究结果将对木麻黄种子园营建中花粉隔离带的设置、雌雄株的配置、种子产量和质量的提高等有重要的理论价值和实践意义。

Pollen is the main carrier of gene flow in plant. Pollen dispersal distances and patterns affect not only genetic structures and diversities of plant population, but also reproductive success and progeny fitness of plant itself. According to published references, studies on pollen dispersal were mainly focused on naturally distributed plant under population scale, but effects of pollen dispersal of introduced tree species on reproductive success and progeny fitness under individual level have not been well documented. In this study, seeds from a female tree and twig samples from all potential pollen donors will be collected from a seedling plantation of Casuarina equisetifolia. At the same time, twig samples from a male tree and seeds from all potential pollen recipients will be collected from the same plantation. The collected progenies and twig samples will be subjected to paternity analysis using SSR technique, and pollen dispersal distances and patterns in plantation will be analyzed based on determining the pollen donors of all progenies. One potted grafted male tree with blooming flowers will be set as the focal tree, potted grafted female ramets with blooming flowers will be arranged around the focal tree in different distances and directions respectively, and pollen capturers are fixed in each ramets. Pollen dispersal patterns, pollen densities and pollen limitation values in different distances and directions around the focal tree will be measured, and their effects on reproductive success and progeny fitness of C. equisetifolia will be determined. Results from this study will provide important theoretical and practical values on setting buffer zones, allocating male and female individuals, improving seed yield and quality during establishment and management of C. equisetifolia seed orchards.