Abstract: In order to probe the impact of Trifolium repens L. root exudate in the process of invading turfgrass, the effects of different levels of Trifolium repens L. root exudate on the seeds and plants of Lolium perenne L., Festuca rubra L., Festuca arundinacea Schreb., Poa pratensis L., Agrostis stolonifera L. were studied with indoor bio-assay. Results showed that root exudates containing phenolics improved seed germination and plant height of tested turfgrass in low levels (0.002 g·mL^-1), whereas inhibited in high levels (0.05 g·mL^-1) (P<0.05). The root exudate prominently decreased the plant root length, but had different impacts on the dry and fresh weight of receptors due to the variant turfgrass species. The root exudate affected the five tested turfgrass to variable extent and the sensitive order was Festuca rubra L.>Festuca arundinacea Schreb.>Poa pratensis L.>Lolium perenne L.>Agrostis stolonifera L.. This research showed that the root exudate of Trifolium repens L. had the allelopathy effect on the five turfgrass types as well as it is one reason why Trifolium repens L. invaded the turfgrass.

Key words: Trifolium repens L., Root exudate, Turfgrass, Allelopathy

摘要： 为探讨根系分泌物在白三叶(Trifolium repens L.)入侵禾本科(Gramineae)草坪过程中的作用,采用水培法收集白三叶根系分泌物、室内生物测定法检测不同浓度的白三叶根系分泌物对多年生黑麦草(Lolium perenne L.)、紫羊茅(Festuca rubra L.)、高羊茅(Festuca arundinacea Schreb.)、草地早熟禾(Poa pratensis L.)和匍匐翦股颖(Agrostis stolonifera L.)种子和幼苗的影响。结果表明:含有酚类化感物质的白三叶根系分泌物对5种受体植物的种子萌发以及幼苗的苗高具有低浓度(0.002 g·mL^-1)促进,高浓度(0.05 g·mL^-1)抑制的效应(P<0.05)。白三叶根系分泌物对各受体幼苗的根长均有显著的抑制作用,而对幼苗干鲜重的影响则因受体种类的不同而不同。白三叶根系分泌物对5种受体表现出不同程度的化感效应,其强弱顺序为:紫羊茅>高羊茅>草地早熟禾>黑麦草>匍匐翦股颖。因此,白三叶根系分泌物对5种草坪草具有一定的化感作用,可能是白三叶入侵禾本科草坪的机制之一。

关键词: 白三叶, 根系分泌物, 草坪草, 化感作用