银合欢叶片水提液对3种蔬菜种子萌发的化感效应

Allelopathy effects of leaf water extracts from an invasive species Leucaena leucocephala on the seed germinations of three brassicaceae vegetable species

研究外来入侵植物银合欢(Leucaena leucocephala)叶片的化感作用,为揭示潜在的生态危害提供参考。配置不同浓度的银合欢叶水提液处理3种十字花科蔬菜种子,按生物测定方法及公式计算其化感指数和综合效应。结果显示,随着银合欢叶水提液浓度的增加,对芥菜(Brassica juncea)、菜心(B.parachinensis)和白菜(B.pekinensis)种子萌发和根长生长的抑制作用增强,且抑制作用大小整体表现为芥菜>菜心>白菜;不同浓度叶水提液对不同受体植物幼苗茎长生长的影响情况较复杂。综合效应指数表明,银合欢叶对3种十字花科蔬菜作物种子萌发均有较明显的化感作用。结果提示,银合欢作为外来入侵植物,因具较强的化感效应,需加强防治。

To reveal the potential ecological damage of an alien invasive species Leucaena leucocephala, the allelopathy effects of leaf water extracts on the seed germination and seedling growth of three vegetable seeds were studied in this paper. By using the biologically determined method and formula, five different concentrations of leaf extracts were used to treat the three cultivated species in Brassieaceae to calculate the indexes of chemical sensitive and synthesis effects. The results showed that with the enhancement of the concentration, the negative effects increase significantly on the seed germination and the root growth of Brassica juncea, B. campestris, and B. pekinensis and the negative effect order showed B. juncea〉B, campestris〉B, pekinensis. The results were complex for stem growth of three different species under different concentration treatments. For the synthesis effect indexes, the Leucaena leucocephcda leaf had a significant chemical sensitive effect on all three different cultivated species in Brassicaceae. As an alien invasive plant, Leucaena leucocephala had a stronger allelopathie effect, and some prevention and cure countermeasures should be taken.