采用培养皿滤纸法,以小麦(Triticum aestivum L.)和玉米(Zea mays L.)为实验材料,以种子的发芽率、发芽指数、活力指数以及幼苗的株高和根长为测定指标,结合化感效应指数的综合效应值,对外来入侵植物野茼蒿[Crassocephalum crepidioides (Benth.) S. Moore]和牛膝菊(Galinsoga parviflora Cav.)茎叶水浸提液的化感活性分别进行了测定。结果表明,随野茼蒿和牛膝菊水浸提液质量浓度(0. 01 ~ 0. 10 g·mL^-1 )的提高,小麦和玉米种子的发芽率、发芽指数、活力指数以及幼苗的株高和根长总体上逐渐减小;与对照组相比,0. 01 g·mL^-1 牛膝菊水浸提液对小麦的幼苗株高以及玉米的种子发芽率和幼苗株高具有一定的促进作用,但对小麦和玉米的幼苗根长有显著抑制作用;而0. 01 g·mL^-1 野茼蒿水浸提液仅对小麦种子的发芽率略有促进作用。0. 04 ~0. 10 g·mL^-1 野茼蒿和牛膝菊水浸提液对小麦和玉米种子萌发及幼苗生长的各项指标基本上均有显著的抑制作用;野茼蒿和牛膝菊水浸提液对玉米种子萌发和幼苗生长的抑制作用大于小麦。0. 01 ~0. 10 g·mL^-1 野茼蒿和牛膝菊水浸提液对小麦和玉米种子萌发和幼苗生长的化感效应指数的综合效应值均小于0,表现为抑制作用,并随2 种植物水浸提液质量浓度的提高综合效应值逐渐降低,且前者的化感效应指数的综合效应值大于后者。研究结果显示,野茼蒿和牛膝菊水浸提液对小麦和玉米的化感活性均表现为抑制作用,且化感作用的强度与水浸提液的质量浓度相关;野茼蒿水浸提液的化感作用效应大于牛膝菊。

Using wheat (Triticum aestivum L.) and maize (Zea mays L.) as experimental materials and using germination rate, germination index and vigour index of seed, height and root length of seedling as determination indexes, as well as combined with synthesis effect value of allelopathic response index, the allelopathic activity of water extracts from leaf and stem of two alien invasive plants Crassocephalum crepidioides (Benth.) S. Moore and Galinsoga parviflora Cav. was studied respectively by the culture dish-filter paper method. The results show that all of germination rate, germination index and vigour index of seed, height and root length of seedling of wheat and maize generally reduce with two water extract concentration increasing (0. 01-0. 10 g·mL^-1 ). Comparing with the control, 0. 01 g·mL^-1 water extract from G. parviflora has a certain promotion to seedling height of wheat and seed germination rate and seedling height of maize, but has a significant inhibition to seedling root length of wheat and maize. And only 0. 01 g · mL^-1 water extract from C. crepidioides has a slight promotion to seed germination rate of wheat. While all of 0. 04-0. 10 g·mL^-1 water extracts from C. crepidioides and G. parviflora appear significant inhibition to seed germination and seedling growth of wheat and maize. On the whole, the inhibition of water extracts from C. crepidioides and G. parviflora to seed germination and seedling growth of maize is stronger than those of wheat. Synthesis effect values of allelopathic response index of 0. 01-0. 10 g·mL^-1 water extracts from C. crepidioides and G. parviflora are all below zero, showing inhibition effects to seed germination and seedling growth of wheat and maize, and decrease gradually with the water extract concentration rising. And the synthesis effect value of allelopathic response index of the former is bigger than that of the latter. It is concluded that allelopathic activity of water extracts from C. crepidioides and G. parviflora is the inhibition effects to wheat and maize, and the inhibition strength relates to the concentration of water extracts. Moreover, the allelopathic activity of water extract from C. crepidioides is stronger than that from G. parviflora.