不同基因型冬小麦镉累积差异及其与根系形态的关系

Difference of Cadmium Accumulation by Different Genotypes of Winter Wheat and Its Relationship with Root Morphology

为了探讨不同冬小麦品种对镉吸收的差异性及其与根系形态的关系,利用水培试验研究不同浓度Cd处理下籽粒镉含量较高的新麦9817(XM)和籽粒镉含量较低的洛优9909(LY)2个小麦品种吸收、累积镉的差异及其根系形态变化特征。结果表明:同一镉浓度下,LY的生物量高于XM,且单株镉累积量高于XM,其对镉胁迫有更好的适应性。中高浓度镉(50,100μmol/L)处理下,LY根系中Cd含量高于XM,而Cd迁移系数低于XM。植株体内镉迁移系数低是造成小麦籽粒中Cd含量低的主要原因。低浓度镉(10μmol/L)胁迫对LY的粗根系的根长、根表面积、根体积有促进作用,XM则表现为抑制作用。中高浓度镉(50,100μmol/L)处理,对XM和LY根系均为抑制作用。XM植株体内镉累积量与根系总根长、根系表面积、根体积的相关系数分别为-0.868,-0.864,-0.838,均为极显著负相关;LY镉累积量与根系总长根系总根长、根系表面积、根体积均为极显著负相关,相关系数分别为-0.936,-0.933,-0.875。根系直径与镉累积量不存在相关关系。

A hydroponic experiment was conducted to study the differences of the Cd absorption and accumulation and the root morphology of 2 winter wheat varieties：Xinmai（XM）,which had high cadmium concentration in kernel,and Luoyou 9909（LY）,which had low Cd concentration in kernel,under the treatments of different cadmium concentration.The results showed that：at the same cadmium level,the biomass of LY was higher than that of XM,and the accumulation of cadmium for an individual plant of LY was higher than that of XM.LY had better adaptability to cadmium stress.On medium and high cadmium levels（50μmol/L and 100μmol/L）,cadmium concentrations in roots of LY were higher than those of XM,but cadmium migration coefficients of LY were lower than those of XM.The low cadmium concentration in wheat kernel was mainly caused by low cadmium migration coefficient of the plant.Low cadmium level（10μmol/L）promoted the root length,root surface area and root volume of thick roots of LY,but restrained those of XM.Medium and high cadmium levels（50μmol/L and 100μmol/L）inhibited the root growth of LY and XM.The cadmium accumulation quantity in XM plant had significantly negative correlation with total root length,root surface area and root volume,with the correlation coefficients of-0.868,-0.864and-0.838,respectively.Cadmium accumulation quantity in LY plant also had significantly negative correlation with the root length,root surface area and root volume of LY,with the correlation coefficients of-0.936,-0.933,and-0.875,respectively.But there was no correlation between root diameter and cadmium accumulation.