巴茅草水浸提液对3种作物种子萌发及幼苗生长的化感作用

本文以发芽率、发芽速度指数、发芽指数、根长、茎长和生物量为种子萌发和幼苗生长参数,研究不同生长时期巴茅草叶片和茎秆水浸提液对白菜、生菜、水稻的化感作用。结果表明: 巴茅草叶水浸提液化感作用强于茎秆水浸提液,叶水浸提液处理后受体植物的发芽指数和生物量均显著低于茎水浸提液。枯萎期巴茅草的化感作用强于生长旺盛期。不同浓度巴茅草叶水浸提液对3种作物的化感作用存在明显的量效关系,浸提液浓度越高,巴茅草的化感抑制作用越强。巴茅草叶水浸提液对白菜和生菜各萌发指标100%抑制的浓度分别为0.075和0.10 g·mL^-1;而0.10 g·mL^-1巴茅草叶水浸提液对水稻发芽率、发芽速度指数、发芽指数的抑制率分别为13.8%、27.2%、19.3%。巴茅草叶水浸提液对白菜和生菜各生长指标100%抑制的浓度分别为0.05和0.10 g·mL^-1;而0.10 g·mL^-1巴茅草叶水浸提液对水稻根长、茎长、生物量的抑制率分别为64.6%、92.9%、21.8%。结合种子萌发和幼苗生长的综合化感指数,3种供试作物对巴茅草化感作用的敏感程度为白菜>生菜>水稻。

Allelopathic effects of Miscanthus floridulus on seed germination and seedling growth of three crops

Allelopathic effects of Miscanthus floridulus at different growth stages on Brassica peki-nensis, Lactuca sativa, and Oryza sativa were examined using six parameters of seed germination and seedling growth, including germination rate, germination speed index, germination index, root length, stem length, and biomass. The results showed that the allelopathic effects of M. floridulus leaf extract were stronger than that of stem extract, with the germination index and biomass of reci-pient plants treated by leaf extract being significantly lower than those treated by stem extract. The allelopathic effect of M. floridulus in the withering stage was stronger than that in the vigorous growth stage. There was a significant dose-effect relationship between the concentrations of leaf extract and the allelopathic effects on three different receptor plants. The higher the extract concentration was, the stronger the allelopathic inhibition was. Leaf extract of M. floridulus could completely inhibit all the germination indices of B. pekinensis and L. sativa at the concentrations of 0.075 and 0.10 g·mL^-1, respectively. The inhibition rates of 0.10 g·mL^-1 leaf extract on germination rate, germination speed index, and germination index of O. sativa were 13.8%, 27.2% and 19.3%, respectively. Leaf extract of M. floridulus could completely inhibit all the growth indices of B. pekinensis and L. sativa at the concentrations of 0.05 and 0.10 g·mL^-1, respectively. However, the inhibition rates of 0.10 g·mL^-1 leaf extract on root length, stem length, and biomass of O. sativa were 64.6%, 92.9% and 21.8%, respectively. In summary, according to the comprehensive allelopathy response index (SE) of seed germination and seedling growth, the susceptibility of the three tested species to the extracts of M. floridulus was B. pekinensis (Cruciferae) > L. sativa (Compositae) > O. sativa (Gramineae).