菊科12种外来植物的有性繁殖特征和入侵风险研究

菊科植物具有极强的有性繁殖能力,对外来菊科观赏植物的引进存在极高的入侵风险。本研究以武汉常见的菊科12种外来观赏植物为对象,通过有性繁殖特征调查,研究植株的花部特征、花粉活力、传粉系统、种子产量,分析各物种有性繁殖能力的差异,评估其入侵能力。结果显示,多数物种可在隔绝传粉者情况下结实;访花昆虫类型多样,共观察到26种访花昆虫,其中膜翅目蜂类是主要的传粉者;结实情况具有一定差异。综合考虑花粉活力、传粉情况和结实情况,认为黑心金光菊(Rudbeckia hirta L.)、松果菊(Echinacea purpurea(L.)Moench)、大花金鸡菊(Coreopsis grandiflora Hogg.)、蛇目菊(Sanvitalia procumbens Lam.)的有性繁殖竞争力较高,对本地传粉环境可能有较大影响。本研究对近缘物种有性繁殖特征的综合分析结果可为评估外来物种的入侵风险提供一定的参考。

Investigation on sexual reproduction and invasion risk of 12 alien Compositae species

Plant species of Compositae exhibit superior sexual reproduction. The introduction of Compositae species for ornamental use may cause a high invasion risk. In this study, we investigated the sexual reproductive traits of 12 ornamental Compositae species. The floral characteristics, pollen viability, pollination system, and seed production were compared among species to assess their sexual reproductive ability and invasion risk. Results showed that most plant species could reproduce without pollinators. In addition, 26 species of insects, categorized into six orders and 16 families, were observed to visit the experimental flowers. Bees were the most frequent pollinators, followed by butterflies and flies. Plant species differed in pollinator assemblage and visitation rate, as well as reproductive success. Considering pollen viability, pollination system and seed production, we regarded Rudbeckia hirta L., Echinacea purpurea (L.) Moench, Coreopsis grandiflora Hogg., and Sanvitalia procumbens Lam. to be successful in pollination and sexual reproduction in this region, with a high risk of invasion. By comparing the sexual reproductive traits among related species, we provide instructions for assessing the invasion risk of introduced plant species.