马缨丹对莴苣种子萌发和幼苗生长的影响

目的]了解马缨丹的入侵机制和对植物生长的影响以及需光种子的萌发特性。方法]通过室内种子萌发法研究了马缨丹叶片乙醇提取物对需光种子莴苣在光暗不同条件下的萌发和幼苗生长的影响。结果]在光照条件下,马缨丹乙醇提取物对莴苣种子的发芽率、发芽势、萌发指数以及根长有明显的抑制作用,其化感作用具有浓度效应,但对芽的生长无影响。在暗处理时,低浓度(小于250μg/ml)的马缨丹乙醇提取物能提高莴苣种子的发芽率、发芽势、萌发指数以及促进幼苗根和芽的生长,说明低浓度的马缨丹乙醇提取物在黑暗中能对需光种子莴苣的萌发起到一定的补偿作用。结论]为阐明外来植物入侵的化学机制提供了理论依据。

Effects of Lantana camara on Germination of Lettuce Seed and Growth of Seedling

Objective ] The aim was to understand the invasive mechanism of L. camara and the effect on plant growth and the germination characteristics of light seed. Method] The effects of ethanol extracts of L. camara leaves on germination of lettuce seed and growth of seed- ling in different conditions of light and dark were studied by indoor germination method. Result] Under the condition of light, ethanol extract of L. camara had a considerable inhibitory effect on germination rate, germination vigor, germination index and root length of lettuce, and the allelopathy has a concentration effect, but no effect on bud growth. In the dark treatment, low concentrations （less than 250μg/ml） of L. ea- mara ethanol extract could improve the lettuce seed germination rate, germination vigor, germination index, bud length and root length, which indicated that the ethanol extract of low concentration had certain positive effect on light seed lettuce in the dark. Conclusion] The research results provide theoretical basis for introducing chemical mechanism of exotic plant invasion.