镉胁迫对碱蓬种子萌发及幼苗生长的影响

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Suaeda glauca

为探究镉(Cd)污染对盐碱湿地植被的毒性效应,以盐碱湿地典型植物碱蓬为供试植物,采用溶液培养方法研究了0～300mg·L-1镉胁迫下碱蓬种子萌发特征及幼苗生长特征。结果表明,3mg·L-1镉胁迫显著提高发芽势、发芽指数、根冠比、幼茎直径、根系直径并降低根系长度(P<0.05),10mg·L-1镉胁迫显著提高活力指数、幼茎重量、根系重量并降低根系活力(P<0.05),30mg·L-1镉胁迫显著提高发芽率和幼茎长度(P<0.05)。主成分分析结果表明,在第一主成分上碱蓬种子发芽势具有最高的载荷,说明发芽势可以很好地反映镉胁迫下碱蓬的生长状态。碱蓬种子发芽势可以作为一种潜在的生物标志物,在盐碱湿地镉污染监测或表征中具有较大的应用潜力。

The aim of this study was to evaluate the effect of cadmium(Cd) on the plants growth in saline-alkaline wetland. As a typical plant grown in such wetland, Suaeda glauce was chosen for this investigation. The seed germination and seedling growth properties of Suaeda glauce exposed to Hoagland′s solution with Cd concentration of 0, 1mg·L-1 , 3mg·L-1 , 10mg·L-1 , 30mg·L-1 , 100mg·L-1 and 300mg·L-1 were analyzed. Cd concentration of 3mg·L-1 significantly enhanced germination potential, germination index, root/shoot ratio, shoot diameter and root diameter; Cd concentration of 10mg·L-1 significantly enhanced vigor index, shoot weight and root weight; Cd concentration of 30mg·L-1 sig-nificantly enhanced germination and shoot length; Cd concentration of 3mg·L-1 and 10mg·L-1 significantly decreased root length and root activity respectively (P<0.05) . Principal component analysis showed seed germination potential got highest loading score at the first principal component, indicating this factor was effective to reflect the growth state of Suaeda glauce under Cd stress. Therefore seed germination potential of Suaeda glauce might serve as potential biomarker, which was helpful to the monitor or evaluation of Cd pollution in salinealkaline wet-land.