白三叶水浸液对草坪草的化感作用

摘要

In order to investigate the reason of Trifolium repense L. invading Gramineae turfgrasses, the al elopathy of T. repense aqueous extracts at different concentrations on seed germination and seedling growth of three turfgrasses i.e. Lolium perenne L., Festuca arundinaces Schreb. and Poa pratensis L. was studied with bio-assay. The results were as fol ows:T. repense aqueous extracts enhanced seed germina-tion rate, germination energy and seedling height of three turfgrasses at low concentrations, whereas inhibited at high concentrations, the inhibiting effect was obviously stronger than the promoting effect. The aqueous extracts possessed significantly inhibiting effect on seedling root length of three turfgrasses, which was much stronger at higher concentrations of aqueous extracts. The influence of T. repense aqueous extracted on germination index, vigor index and fresh weight was different among different turfgrass species. The above results demonstrated that T. repense aqueous extracts possessed al elopathy, which could impact the normal growth of three turfgrasses and was also a reason why T. repense invaded Gramineae turfgrasses.%为探讨白三叶入侵禾本科草坪草原因，利用生物测定法研究不同浓度白三叶水浸液对多年生黑麦草、高羊茅、草地早熟禾三种禾本科草坪草种子萌发和幼苗生长的化感作用。结果表明，白三叶水浸液对多年生黑麦草、高羊茅和草地早熟禾三种草坪草种子发芽率、发芽势和幼苗苗高具有低浓度促进、高浓度抑制的双重效应，且抑制作用明显强于促进作用；对幼苗根长具有显著的抑制作用，且抑制作用随着白三叶水浸液浓度的增加而增强；对种子发芽指数、活力指数和幼苗鲜重的影响则因草坪草种类的不同而不同。结果表明，白三叶水浸液具有化感作用，影响三种草坪草的正常生长，是白三叶入侵禾本科草坪草的原因之一。