玉米根系、根鞘性状与镉吸收的品种差异研究

采用云南主栽的12个玉米品种,开展盆栽试验,研究Cd污染土壤中玉米根系形态、根鞘性状与植株Cd累积特征及品种间的差异性。结果发现,不同品种玉米的生物量、根系形态、根鞘性状及植株Cd累积特征均存在显著差异,其中根长、根表面积、根体积、根尖数、分枝数差异较大,最大值分别为最小值的2.9、2.9、3.2、5.5、6.1倍,平均根系直径差异较小,最大值为最小值的1.48倍;根鞘质量、根鞘发育指数、根鞘土壤有效态Cd含量最大值分别为最小值的3.1、5.8、1.8倍,地上部、地下部Cd含量最大值分别为最小值的6.4、6.1倍,地上部、地下部Cd累积量最大值分别为最小值的6.5、4.0倍。相关性分析表明,根表面积和根体积与地上部Cd含量呈显著负相关,根尖数与地下部Cd含量呈极显著负相关;根鞘质量与地上部Cd含量呈极显著负相关,根鞘发育指数与地下部Cd含量呈极显著正相关。研究表明,根系形态和根鞘性状是导致不同品种玉米Cd吸收差异的重要因素。

Differences in root morphology, rhizosheath traits, and Cd uptake in maize cultivars

A pot experiment was conducted using 12 Yunnan maize cultivars to study the different responses of root morphology, rhizosheath characteristics, and Cd accumulation characteristics in Cd-contaminated soil. The results showed that there were significant differences in the biomass, root morphology, rhizosheath characteristics, and Cd accumulation characteristics in different maize cultivars. Among them, the root length, root surface area, root volume, root tip number, and branch number were greatly different, with maximums were 2.9, 2.9, 3.2, 5.5, and 6.1 times of minimums, respectively. The difference in the average root diameter was small, with the maximums was 1.48 times of the minimum. The largest differences in the rhizosheath weight, rhizosheath development index, and available Cd content in the rhizosheath soil were 3.1, 5.8, and 1.8 times, respectively. The maximums in the Cd content in the shoots and roots were 6.4 and 6.1 times of minimums, respectively. The maximums in the Cd accumulation in the shoots and roots were 6.5 and 4.0 times of minimums, respectively. Correlation analysis showed that the root surface area and root volume were significantly negatively correlated with the shoot Cd content, while the root tip number was significantly negatively correlated with the root Cd content. The rhizosheath weight was significantly negatively correlated with the shoot Cd content, while the rhizosheath development index was significantly positively correlated with the root Cd content. Thus, the different responses of Cd uptake were attributed to the root morphology and rhizosheath characteristics.