Data from: Suppression of reproductive characteristics of the invasive plant Mikania micrantha by sweet potato competition

Background: As a means of biologically controlling Mikania micrantha H.B.K. in Yunnan, China, the influence of sweet potato [Ipomoea batatas (L.) Lam.] on its reproductive characteristics was studied. The trial utilized a de Wit replacement series incorporating six ratios of sweet potato and M. micrantha plants in 25 m2 plots over two years. Results: Budding of M. micrantha occurred at the end of September; flowering and fruiting occurred from October to February. Flowering phenology of M. micrantha was delayed (P<0.05), duration of flowering and fruiting was reduced (P<0.05) and duration of bud formation was increased (P<0.05) with increasing proportions of sweet potato. Reproductive allocation, reproductive investment and reproductive index of M. micrantha were significantly reduced (P<0.05) with increasing sweet potato densities. Apidae bees, and Calliphoridae or Syrphidae flies were the most abundant visitors to M. micrantha flowers. Overall flower visits decreased (P<0.05) as sweet potato increased. Thus the mechanism by which sweet potato suppressed sexual reproduction in M. micrantha was essentially two-fold: causing a delay in flowering phenology and reducing pollinator visits. The number, biomass, length, set rate, germination rate, and 1000-grain dry weight of M. micrantha seeds were suppressed (P<0.05) by sweet potato competition. With proportional increases in sweet potato, sexual and asexual seedling populations of M. micrantha were significantly reduced (P<0.05). The mortality of both seedling types increased (P<0.05) with proportional increases in sweet potato. Conclusions: These results suggest that sweet potato significantly suppresses the reproductive ability of the invasive species M. micrantha, and is a promising alternative to traditional biological control and other methods of control. Planting sweet potato in conjunction with other control methods could provide a comprehensive strategy for managing M. micrantha. The scenario of controlling M. micrantha by utilizing a crop with a similar growth form may provide a useful model for similar management strategies in other systems.

背景：为实现中国云南地区薇甘菊（Mikania micrantha H.B.K.）的生物防控，本研究探讨了甘薯[Ipomoea batatas (L.) Lam.]对其生殖特性的影响。本试验采用德威特（de Wit）替代系列设计，在25平方米的样地中设置6种甘薯与薇甘菊植株占比组合，试验周期为两年。结果：薇甘菊的现蕾期为9月末，开花与结实期为10月至次年2月。随着甘薯占比升高，薇甘菊的开花物候期显著延迟（P<0.05），开花结实时长显著缩短（P<0.05），而现蕾时长显著延长（P<0.05）。随着甘薯种植密度升高，薇甘菊的生殖分配、生殖投入及生殖指数均显著降低（P<0.05）。访花昆虫中以蜜蜂科（Apidae）蜂类、丽蝇科（Calliphoridae）或食蚜蝇科（Syrphidae）蝇类最为常见。随着甘薯占比升高，薇甘菊的总访花频次显著降低（P<0.05）。综上，甘薯抑制薇甘菊有性生殖的机制主要有两点：一是延迟其开花物候期，二是降低其传粉昆虫访花频次。薇甘菊种子的数量、生物量、长度、结实率、发芽率及千粒干重均因甘薯的竞争作用显著降低（P<0.05）。随着甘薯占比升高，薇甘菊的有性与无性幼苗种群数量均显著降低（P<0.05）。两类幼苗的死亡率均随甘薯占比升高显著上升（P<0.05）。结论：本研究结果表明，甘薯可显著抑制入侵物种薇甘菊的生殖能力，有望替代传统生物防控及其他防控手段。将甘薯种植与其他防控手段相结合，可为薇甘菊的综合治理提供可行方案。利用生长型相似的作物防控薇甘菊的思路，可为其他生态系统中的同类防控策略提供参考范式。