【摘要】 化感作用在生物入侵过程中具有重要的意义。利用培养皿滤纸法研究了入侵物种白花鬼针草(Bidens pilosa L.var.radiate Sch-Bip.)水浸提液对4种植物的种子萌发和幼苗生长量的影响。结果表明:白花鬼针草水浸提液对4种受试植物的种子萌发和幼苗生长量均有化感作用,不同浓度的提取液对植物的化感作用强度不同,高浓度(≥0.1 g/mL)提取液能降低酢浆草种子发芽率、发芽指数和幼苗生长量;高浓度提取液能提高龙葵种子的萌发率、发芽指数,而对皱果苋和绿豆种子影响不大。其中发芽指数更敏感,可能是衡量化感作用的最敏感指标。不同植物对白花鬼针草化感作用的敏感程度不同,酢浆草和龙葵种子对白花鬼针草化感作用较敏感,绿豆最不敏感。更多还原

【Abstract】 It was hypothesized that allelopathy played an important role in biological invasion.In this study we determined the effects of aqueous extracts of Bidens pilosa var.radiate on seed germination and seedling growth of four species.The results showed that the allelopathic effects of the extracts from both below and above grounds parts of B.pilosa var.radiate were enhanced with increasing concentration.The results showed that the allelopathic effects of the extracts from both below and above grounds parts of B pilosa var.radiate were enhanced with increasing concentration.The aqueous extracts with high concentrations(≥0.1 g/mL) had a considerable inhibitory effect on seed germination,germination index and weight of the seedling of Oxalis corniculata,but had a facilitating effect on seed germination and germination index of Solanum nigrum,and had seldom effect of Amaranthus viridis and Vigna radiate.Seed germination index was more sensitive to the aqueous extracts than seed germination rate,which might be the most sensitive index to judge allelopathy,among parameters mentioned above.Sensitivity to the aqueous extracts were different among the species tested in this study,Oxalis corniculata and Solanum nigrum were sensitive to B.pilosa var.radiate allelochemicals,but Vigna radiate was not.更多还原