【摘要】 探讨三七连作土壤的化感作用,初步揭示三七连作土壤化感作用的机制。采用不同质量浓度三七连作土壤水提液对三七、莴苣种子萌发及幼苗生长进行生物测定。结果表明,三七连作土壤水提液对三七、莴苣的发芽率、发芽指数、根长、苗高、鲜质量、硝酸还原酶活性均有不同的化感作用。随着三七连作土壤水提液质量浓度的不断提高,连作土壤对三七苗高、鲜质量的抑制作用也在明显增加;三七连作土壤水提液对莴苣根长的作用呈低促高抑的双重效应,不同质量浓度的土壤水提液对莴苣的硝酸还原酶活性均呈显著的抑制作用。三七连作土壤水提液中存在着化感物质影响三七和莴苣种子及幼苗的正常生长,其化感作用与土壤中化感物质浓度密切相关。更多还原

【Abstract】 The allelopathic effect of continuous cropping soil of Panax notoginseng was investigated and its mechanism was revealed initially.The bioactivities of continuous cropping soil of Panax notoginseng were evaluated on seeds germination and seedlings growth of Pseudo-ginseng and lettuce.The allelopathic effect of continuous cropping soil of Panax Pseudo-ginseng on germination rate,germination index,root length,seedling height,fresh weight and NR activity of Pseudo-ginseng and lettuce was different.As the concentration of the extracts from Pseudo-ginseng continuous cropping soil increased,the suppression on seedling height and fresh weight of Pseudo-ginseng increased;there were dual effects on root length of lettuce.The suppression of different concentration on NR activity of Lettuce was significant.There were some substances which had some influence on the normal growth of Pseudo-ginseng and lettuce in aquatic extract from Pseudo-ginseng continuous cropping soil and the close relationship existed between allelopathy and contention of allelochemicals.更多还原