中文摘要：

空心莲子草（Alternanthera philoxeroides Griseb）为广泛分布且亟待解决防除的重要外来恶性杂草,其化感作用机制近年来逐渐引起人们的广泛关注。该研究通过添加空心莲子草地上和地下水浸提液和土壤灭菌处理来研究其对白三叶种子萌发和幼苗生长的影响,以期深入理解空心莲子草的化感作用及其机理。结果表明,土壤灭菌和空心莲子草浸提液处理及其交互作用对白三叶种子萌发率及其幼苗的芽长和根长均有显著或极显著影响。在基质未灭菌条件下,空心莲子草的地下浸提液表现为促进效应,而地上浸提液表现为抑制效应;在基质灭菌条件下,空心莲子草地上和地下浸提液均表现为抑制效应,但其抑制程度存在差异。相比地上浸提液,地下浸提液的抑制程度更大且不同器官响应存在差异。相对于芽长,根长受到的抑制作用更大。由此可见,空心莲子草地下浸提液与地上浸提液的化感效应存在一定的差异,在对其化感机理的研究中不仅要关注植株不同部位的作用效应差异,同时要关注外界环境条件特别是土壤微生物的影响。

英文摘要：

Alternanthera philoxeroides Griseb is a worldwide weed and urgently needed to be controlled and removed, of which the allelopathy mechanism has gradually aroused people＇s extensive attention in recent years. To deeply understand its allelopathy mechanism, the seeds of Trifolium repens are subjected to the treatment groups of sterilization and aqueous extracts from A. philoxeroides. The results showed that sterilization and aqueous extracts from A. philoxeroides and their interactive effects had significant impacts on the seed germination, bud length and root length of T. repens. Under the condition of non-sterilization in soil, the underground aqueous extracts from A. philoxeroides had positive effects on T. repens and the aboveground ones had negative impacts. However, under the condition of sterilization in soil, both the underground aqueous extracts and the aboveground ones from A. philoxeroides had negative effects, but there were differences between the degree of their impacts. Compared to the aboveground ones, the effects of underground ones were more worse. Compared to the bud length as well, the root length was more vulnerable to the negative impacts of aqueous extracts from A. philoxeroides. In a word, there were some differences between the effects of the aqueous extracts from different parts of A. philoxeroides, and it was suggested that to study the allelopathy of A. philoxeroides, we should not only pay attention to the different parts of A. philoxeroides, but also to the external environment conditions, especially the microbes in the soil.