Thiébaut Gabrielle, Tarayre Michèle, Rodríguez-Pérez Héctor
ECOBIO, UMR 6553 CNRS, Université de Rennes 1, Rennes, France.
Front Plant Sci. 2019 Jul 2;10:854. doi: 10.3389/fpls.2019.00854. eCollection 2019.
Allelopathy is defined as the effects (stimulatory and inhibitory) of a plant on the development of neighboring plants through the release of secondary compounds. Autoallelophaty is the beneficial or harmful effect of a plant species on itself. The allelopathic potential belonging to a native species could induce a biotic resistance against invasive plants, whereas allelochemicals released by exotic species could favor the establishment of invasive species (invasional meltdown). The aim of our study was to examine the potential allelopathic effect of four plant species on the target species using two experiments. In the first experiment, we tested the allelopathic effect of root and leaf leachates of the two congeneric exotic species and on while in the second experiment, we studied the allelopathic effect of root and leaf leachates of a sympatric exotic species and of one native species on . We measured the stem length to calculate the relative growth rate and four physiological traits (nitrogen balance index and flavonol, chorophyll, anthocyanin indices) of the target plants on a weekly basis. At the end of the experiment, we determined the aboveground and belowground biomass. We also counted the number of lateral branches and measured their lengths. We found that the root leachates of and of had stimulated the synthesis of flavonols of Leaf leachate of also stimulated its own flavonol synthesis. Also, the root leachate of had stimulated the total biomass and length of lateral branches of whereas the production of lateral branches had been stimulated by root leachates of both species and by leaf leachate of The autoallelopathy of could explain its invasiveness. Both leachates produced by had no effect on the physiological and morphological traits of the invasive and indicated no biotic resistance in the recipient community. The two invasive plant species and could favor the establishment of . These results suggested an "invasional meltdown."
化感作用被定义为一种植物通过释放次生化合物对邻近植物发育产生的影响（刺激和抑制）。自毒作用是指一个植物物种对其自身的有益或有害影响。本地物种的化感潜力可能会对入侵植物产生生物抗性，而异种植物释放的化感物质可能有利于入侵物种的建立（入侵崩溃）。我们研究的目的是通过两个实验来检验四种植物对目标物种的潜在化感作用。在第一个实验中，我们测试了两种同属外来物种和的根和叶浸出液对的化感作用，而在第二个实验中，我们研究了一个同域外来物种和一个本地物种的根和叶浸出液对的化感作用。我们每周测量目标植物的茎长以计算相对生长率，并测量四个生理特征（氮平衡指数以及黄酮醇、叶绿素、花青素指数）。在实验结束时，我们测定了地上和地下生物量。我们还统计了侧枝数量并测量了它们的长度。我们发现和的根浸出液刺激了的黄酮醇合成。的叶浸出液也刺激了其自身的黄酮醇合成。此外，的根浸出液刺激了的总生物量和侧枝长度，而两种物种的根浸出液和的叶浸出液都刺激了的侧枝产生。的自毒作用可以解释其入侵性。产生的两种浸出液对入侵的的生理和形态特征均无影响，并且在受体群落中未显示出生物抗性。两种入侵植物物种和可能有利于的建立。这些结果表明存在“入侵崩溃”。
