入侵植物紫茉莉遗传毒性的初步研究

The genetic toxicity of an invasive plant,Mirabilis jalapa L.

紫茉莉原产热带美洲,目前已成为中国主要的入侵植物。首次运用蚕豆根尖细胞微核试验研究了入侵植物紫茉莉水浸提液的遗传毒性,探讨其化感作用与入侵性的关系。结果表明,紫茉莉水浸提液使根尖细胞有丝分裂指数降低,微核率升高,细胞中出现了微核、染色体断片、染色体桥、染色体滞留等多种染色体畸变,表现出明显的遗传毒性,水浸提液对有丝分裂的抑制效应表现为处理时间和水浸提液浓度的双重依赖。其地上部分的化感效应大于地下部分的化感效应。在紫茉莉的入侵过程中,其水溶性化感物质可能通过淋溶或根系分泌进入环境,抑制了其他植物的生长发育,成为其迅速扩散的机制之一。蚕豆根尖微核试验在检测入侵植物的化感作用方面具有较大的应用价值。

Mirabilis jalapa L. , native to Tropical America, had become a major invasive plant in China. To evaluate the relationship between allelopathy and invasiveness in M.julapa,the micronucleus test of Vicia fabru toot tip cells was conducted to detect the genetic toxicity induced by the aqueous extracts of M.jalapa. The results showed that the aqueous extracts of M.julapa disturbed mitosis of Vicia fabra toot tip cells. The mitotic index decreased and the mieronueleus frequency increased, and aberrant chromosomes such as mieronueleus, chromosome bridge, chromosome break and chromosome lag occurred. These effects were concentration dependent and time dependent. The allelopathic effect of overground organ was stronger than that of underground organ. The water-solubility allelopathie substance in M. jalapa into environment through eluviation and secretion inhibited growth of other plants,and allelopathy may be one of the mechanisms of M. jalapa rapid spread. The micronucleus test of Viciafabra toot tip cells has great value testing allelopathy of invasive plants.