镉胁迫条件下硅对果蔗幼苗生长及镉吸收的影响

Effects of Silicon on Growth and Cadmium Uptake of Chewing Cane Seedlings under Cadmium Stress

【目的】探究镉(Cd)胁迫条件下硅(Si)对果蔗生长及Cd吸收的影响。【方法】采用砂培试验的方法,以广西普遍种植果蔗品种(Badila)为材料,研究不同Si施量(0、10、20和40 mg/L)对Cd胁迫条件下的果蔗生长指标及Cd吸收的影响。【结果】Cd胁迫条件下,与未施Si的对照处理相比,各施Si处理下果蔗鲜重、株高、根长等指标均有所增加,其中Si用量为20 mg/L处理的果蔗鲜重、株高和根长等指标均为最高,分别比对照处理增加78.74%、303.98%和85.11%。与未施Si相比,各施Si处理果蔗根茎叶Cd的含量均显著降低,降幅达31.69%~61.24%。各施Si处理均可显著增加Cd从根系向叶的转运,转运因子相比对照分别增加27.27%、72.73%和36.36%。【结论】Cd胁迫条件下,施Si可以促进果蔗幼苗的生长,降低果蔗根茎叶中镉的含量,一定程度上缓解了镉对果蔗的毒害作用。

[ Objective ] The experimental objective was to investigate the effects of silicon （Si） on chewing cane seedling growth and its uptake of cadmium （Cd） under Cd stress. [ Method] Using sand culture experiments, a common cultivating chewing cane （Badila） in Guangxi was selected. Si （ as Na2SiO3 ） was applied to sand at four levels of 0, 10, 20 and 40 mg/L, and the effects of different Si treatments were studied on chewing cane seedling growth and its uptake of Cd under Cd stress. [ Result ] Fresh weight, plant height, root length of chewing cane increased with the application of Si. The heaviest fresh weight（ 188.48 g）, the highest plant height （23.35 cm）, tile longest root length （23.75cm） of chewing cane were found at 20 mg/kg silicon treatment, which was increased by 78.74 %, 303.98 % and 85.11% compared with the control, respectively. The results also showed that Cd concentration in root, stem, and leaf of chewing cane decreased with the application of Si. The Cd concentration in root, stem, and leaf of chewing cane were decreased by 31.69 % -61.24 % at silicon treatment compared with the control T1 , and it was found that Si application increased Cd transportation from root to leaf. The transport factors of Cd from root to leaf increased by 27.27 %, 72.73 % and 36.36 % at Si treatment, respectively. [ Conclusion ] Under Cd stress, the application of Si could promote the growth of chewing cane seedlings and reduce the Cd content in root, stem and leaf of chewing cane. To a certain extent, the application of Si alleviated the toxicity of Cd to chewing cane.