【摘要】 两栖蔊菜(Rorippa amphibia)为喜湿的生物入侵植物，采集了其在相对干燥和湿润环境中所结种子(种子Ⅰ、种子Ⅱ),用高浓度聚乙二醇(polyethylene glycol, PEG)胁迫预处理，测定了在不同温度条件下的种子萌发及幼苗生长指标。结果表明，大多数发芽指标、幼苗的株高和根长均随PEG预处理浓度增高而下降。在35℃下处理的发芽率、发芽势、萌发活力、发芽指数均较25℃条件下显著升高，说明35℃高温更适宜两栖蔊菜种子的萌发，而其种子在夏季成熟，该特征使其种子在入侵地成熟后即能大量萌发，这是其成功入侵的一个重要机制。幼苗在25℃下的根生长优于35℃(P<0.01),说明其在相对低温下加大了对地下部分的投入以渡过不利季节，该对策可能是其入侵成功的又一原因。相同PEG预处理下种子Ⅱ的绝大多数发芽指标均高于种子Ⅰ,幼苗Ⅱ的根长和株高也优于幼苗Ⅰ,说明亲代的生存环境对两栖蔊菜种子的发芽和幼苗生长具有重要影响。更多还原

【Abstract】 Rorippa amphibia, which prefers moist environment, is an invasive plant in China. The seeds were collected from relatively dry and moist environments(seeds Ⅰ and seeds Ⅱ), respectively, and subjected to pre-water stress treatment with high concentration of Polyethylene glycol(PEG). The seed germination and seedling growth indexes under different temperatures were then measured. The results showed that most of the germination indexes, seedling growth decreased with the increase of PEG pre-treatment concentration. At 35 ℃, the germination rate, germination potential, germination vigor and germination index of all treatments were significantly higher than those at 25 ℃, indicating that 35 ℃ was more suitable for the germination of its seeds. This characteristic allowed its seeds to germinate in large numbers in its invaded area since its seeds ripened in summer, which was an important mechanism for its successful invasion. The root growth of seedlings at 25 ℃ was better than that at 35 ℃(P<0.01), indicating Rorippa amphibia increased its investment in the underground parts to getting through unfavorable seasons, which might be another reason for its successful invasion. Most of the germination indexes of seed Ⅱ were higher than those of seed Ⅰ under the same PEG pretreatment, and the root length and height of seedling Ⅱ were also better than those of seedling Ⅰ, indicating that the parental survival environment had an important effect on the seed germination and seedling growth of Rorippa amphibia.更多还原