镉胁迫对不同品种甘蔗生长及各器官镉积累的影响

Effect of Cadmium Stress on Sugarcane Growth and Cadmium Accumulation in Different Organs

为了研究土壤镉胁迫对甘蔗生长及镉积累、转移的影响,以4个不同品种甘蔗为材料,通过土壤盆栽的方法,分析镉胁迫下不同甘蔗株高、茎径、生物量、镉含量、积累量、转移系数及分配系数的变化。结果显示:镉胁迫下甘蔗的株高,茎径显著下降,耐镉性品种YT666根系和茎的生物量分别是镉敏感品种ROC22的3.23和2.92倍;在正常土壤生长的甘蔗植株各器官的镉含量与积累量均没有显著差异,但在镉胁迫下,各器官镉含量和积累量显著增加,其中各器官镉含量表现为根>老叶>茎>新叶,而镉积累量为根>茎>老叶>新叶;耐镉性品种YT666总镉积累量最高,镉在根系中的分配系数最高,而敏感品种ROC22总镉积累量较低,但在根系中的分配系数低。由此可见,镉胁迫下耐镉的甘蔗品种保持较高的生长量可能是通过降低镉向地上部分转移来降低镉对甘蔗生长的影响。

Four sugarcane varieties were chosen as experimental materials to investigate the effect of Cd stress on sugarcane growth, Cd accumulation and transfer. The pot experiment was carried out and the change of height,diameter, biomass, Cd content, accumulation amount, distribution coefficient and transfer coefficient were analyzed.The results showed that the height, diameter, biomass of the four varieties significantly decreased under Cd stress.The biomass of root and stem in tolerant variety YT666 was the highest among the four varieties, which was 3.23 and2.92 times higher than those of sensitive variety ROC22. Under normal condition, the Cd content and accumulation amount in the four varieties did not show significant difference. Under Cd stress condition, the Cd content and accumulation amount significantly increased. The Cd contents in the four organs were as follows： root old leaf stemnew leaf, and the Cd accumulation amounts were rootstemold leafnew leaf. The Cd accumulation amount in YT666 was the highest among the four varieties, and the distribution coefficient to root was the highest.However the sensitive variety ROC22 showed the lowest Cd accumulation and the distribution coefficient of roots.These results suggested that the Cd tolerance variety of sugarcane could maintain the growth under Cd stress and the decrease of the Cd transfer from root to shoot might be the strategy of sugarcane to reduce the inhibition of Cd on sugarcane growth.