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.研究背景：为实现中国云南地区薇甘菊（Mikania micrantha H.B.K.）的生物防治，本研究探讨了甘薯[Ipomoea batatas (L.) Lam.]对其繁殖特性的影响。试验采用德威特替代序列（de Wit replacement series）设计，设置6种甘薯与薇甘菊植株占比组合，于25平方米样地中开展，试验周期为两年。试验结果：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。随着甘薯占比提升，薇甘菊的开花物候期显著延后（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）。随着甘薯密度升高，薇甘菊的繁殖分配、繁殖投入与繁殖指数均显著降低（P<0.05）。访花昆虫以蜜蜂科（Apidae）蜂类、丽蝇科（Calliphoridae）或食蚜蝇科（Syrphidae）蝇类为主；随着甘薯占比提升，总访花频次显著降低（P<0.05）。综上，甘薯抑制薇甘菊有性繁殖的核心机制主要有两点：一是延后其开花物候期，二是减少传粉昆虫的访花频次。甘薯的竞争作用可显著抑制薇甘菊种子的数量、生物量、长度、结实率、发芽率以及千粒干重（P<0.05）。随着甘薯占比提升，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提升而显著升高（P<0.05）。研究结论：本研究结果表明，甘薯可显著抑制入侵物种薇甘菊的繁殖能力，有望成为传统生物防治及其他防控手段的替代方案。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路径。通过种植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。