不同生境入侵植物北美车前繁殖器官性状变异与权衡特征

提高繁殖输出是入侵植物成功入侵的重要机制，但不同生境间繁殖器官性状变异特征尤其是性状权衡关系可能会存在差异。以入侵植物北美车前（Plantago virginica）为研究对象，采集草坪、荒地和林下3个生境的植物花序，探究花穗及花序柄的形态、生物量及其异速生长关系在不同生境间的差异性。结果表明：不同生境北美车前大部分花序形态与生物量指标存在显著差异，草坪和荒地生境花序属细长型，而林下生境则为矮壮型。北美车前繁殖器官不同性状间的异速生长关系既有保守型也有易变型，体现出不同的环境敏感性。不同生境间北美车前繁殖器官资源分配的个体大小依赖关系也存在不一致性。可见，北美车前花序性状及资源分配在不同生境间既存在一定的可塑性也具有相对保守性，这可能是其高入侵能力的重要原因。

Variations and Trade-offs in Reproductive Organ Traits of an Invasive Plant Plantago virginica in Different Habitats

Improving reproductive ability of invasive plants might be an important mechanism for successful invasion， but there might be different in variation of reproductive organ traits among the different habitats， especially in the trade-off relationship. The plant Plantago virginica was taken as material， the inflorescences in three habitats including lawn， wasteland and understory， were collected to investigate the differences of morphology， biomass， and the allometric relationship of spikelet and peduncle among different habitats. The results showed that， there were significant differences in most inflorescence morphological and biomass indexes of P. virginica in different habitats. The inflorescences of P. virginica in lawn and wasteland habitats were slender， while that in understory habitat was short and strong. The allometric relationships among different traits of reproductive organs of P. virginica were both conservative and variable， showing different environmental sensitivities. The size dependence of reproductive resource allocation of P. virginica in different habitats was also inconsistent. Therefore， the inflorescence traits and resource allocation of P. virginica in different habitats are both plastic and relatively conservative， which might be an important manifestation of its high invasive ability.