镉在烟草中的积累分配及其对烟草生长的影响

摘要

Tobacco is one of the most important crops in China. Pot experiments were carried out to study the effects of different concentrations of Cd (0, 1.2, 2.4 and 4.8 mg/kg) on the tobacco growth and the characteristics of Cd distribution and uptake by tobacco. The results show that, the dry matter weight of tobacco leaves significantly decreased with the increase of the Cd concentration at the same growth stages (p < 0.01). The dry matter weight of stem increased firstly and then sharply decreased. The dry matter weight of root gradually decreased at the early growth stage (30 d and 45 d), while it slightly increased at first and then decreased rapidly at the later growth stage (60 d and 75 d). The Cd content of leaves significantly higher than that of stems and roots except the control treatment. The Cd content of control performed as: root > stem > leaf. The content of Cd in tobacco leaves showed as: lower leaf middle leaf > upper leaf. The accumulation rate of Cd increased in different parts of tobacco with the increase of the Cd concentration. Cd accumulation rate of tobacco showed as: rapid accumulation- quick reduction -slow accumulation.%为了探明镉在烟草中的积累分配规律，采用盆栽试验，调查了不同镉浓度处理下烟草全生育期的生长及镉在烟草中的分配积累规律。结果表明，随着镉浓度的提高，同一时期烟草叶片的干物质量显著降低（p<0.01），茎部干物质量先升高后降低，根部干物质量在生长前期（30 d和45 d）逐渐降低，生长后期（60 d和75 d）先升高而后降低。各添加镉处理后，叶片镉含量均显著高于茎和根部，而对照镉含量根>茎>叶。烟叶中的镉含量表现为：下部叶中部叶>上部叶。烟草镉积累速率随着镉浓度的增加而升高，烟草各部位的镉积累规律为：快速积累—快速降低—缓慢积累。