入侵物种三裂叶蟛蜞菊挥发物对杂草叶绿素含量的影响

Effects of allelopathy of Wedelia trilobata L.on chlorophyll content of the tested plants

研究了华南地区外来入侵植物三裂叶蟛蜞菊(Wedelia trilobata L.)挥发物对本地区3种主要杂草的叶绿素含量的影响,以揭示其化感作用的机理。结果表明:三裂叶蟛蜞菊植株挥发物和挥发油对稗草(Echinochloa crusgalli(L.)Beauv.)、三叶鬼针草(Bidens pilosa L.)和青葙(Celosia argentea L.)叶绿素含量有明显的抑制作用。在同一实验条件下,250.0 g三裂叶蟛蜞菊新鲜茎叶及含有0.10 mL、0.25 mL和0.50 mL挥发油容器中生长的稗草、三叶鬼针草和青葙的叶绿素含量明显减少,稗草的叶绿素含量分别比对照减少56.5%、41.9%、49.6%和64.9%;三叶鬼针草的叶绿素含量分别比对照减少6.45%、4.35%、15.3%和24.8%;青葙的叶绿素含量分别比对照减少53.3%、17.6%、33.3%和71.5%。结论:三裂叶蟛蜞菊挥发物的化感作用可使受体植物的叶绿素含量减少。其作用机理值得深入研究。

The effect of the volatiles and essential oils of Wedelia trilobata（L.） on the leaf chlorophyll content of three tested plants were investigated to reveal the mechanism of allelopathy in south China.The results showed that the leaf chlorophyll content of all the three tested plants—Echinochloa crusgalli（L.）,Bidens pilosa（L.） and Celosia argentea（L.） grown in the existence of fresh W.trilobata（L.）（250.0 g）,or in the containers with W.trilobata（L.） essential oils（0.10 mL,0.25 mL and 0.50 mL） were greatly re-duced.Compared to the control,the leaf chlorophyll content of E.crusgalli decreased by 56.5%,41.9%,49.6% and 64.9%,respec-tively;those of B.pilosa reduced by 6.45%,4.35%,15.3% and 24.8%,respectively;and those of C.argentea decreased by 53.3%,17.6%,33.3% and 71.5%.These findings indicated that volatiles and essential oils of W.trilobata have allelopathic potentials which inhibit the leaf chlorophyll content of receiver plants.The mechanism needs further studying.