几种豆科牧草地上部水浸提液对稗草种子和幼苗的化感效应

用砂培法研究毛苕子(Vicia villosa)、紫花苜蓿(Medicago sativa.)、白三叶(Trifolium repens)、红三叶(Trifolium pratense)和黄花草木樨(Melilotus officinalis)花期地上部水浸提液对稗草(Echinochloa crusgalli)的化感效应.结果表明,供试草种水浸提液对稗草种子萌发和幼苗生长的化感作用具有明显的种间差异;其中对毛苕子和黄花草木樨种子发芽的抑制作用强于其它3种,抑制率达60%以上;紫花苜蓿对稗草幼苗生长的抑制作用强,特别是对根的抑制作用显著强于其它4个草种;白三叶和红三叶仅在水浸提液浓度0.1 g/mL时,对稗草鲜根重表现出显著的抑制效应(P＜0.05);此外,供试草种浸提液对稗草的化感作用,随着浓度的升高,抑制作用随之增强.

A Study on the Allelopathic Effect of Water Extracts from Aerial Part of Legume Herbages on Germination and Seedling Growth of Barnyard Grass

The allelopathic effect of water extracts of five legume forages, i.e., Vicia villosa,Medicago sativa,Trifolium repens,T. pratense, and Melilotus officinalis, of different concentrations: 0, 0.050, 0.075, and 0.100 g/mL(w/v), on the seed germination and seedling growth of barnyard grass (Echinochloa crusgalli), was investigated. Results indicate that the allelopathic effects of different legume species on barnyard grass varied. Seed germination of barnyard grass was significantly inhibited by the water extracts of hairy vetch and yellow sweet clover, and the inhibition rate exceeded 60%. Seedling growth, especially that of the root, was greatly retarded by the water extract of alfalfa. The results also show that the allelopathic inhibition rate increased with intense concentration of the water extracts.