春夏不同播期玉米籽粒镉积累差异

The Difference of Cadmium Accumulation in Maize Kernels in Spring and Summer Planting

本研究以34个玉米品种为材料,在湖南长沙和湘潭两地镉污染农田设置2个播期处理开展大田试验,探讨春、夏不同播期玉米品种籽粒镉积累差异。结果表明,播期对玉米籽粒镉含量有显著影响,春播镉含量高于夏播。不同玉米品种间籽粒镉含量差异显著,表现出广泛的遗传变异,变异系数大于100%,且广义遗传力可达85%。相关性分析结果表明,土壤镉含量与籽粒镉含量极显著相关,且相同地点不同播期间籽粒镉含量相关系数最高。按照镉积累特点将玉米分为3种类型:籽粒高镉积累型‘康农玉999’;籽粒中镉积累型‘苏玉20’、‘康农18’和‘青青515’;其余30个品种为籽粒低镉积累型。籽粒低镉积累型玉米品种可以作为镉污染农田替代种植的农作物。‘康农玉999’可作为籽粒镉积累相关基因遗传定位的研究材料。

Cadmium concentrations in grains of the 34 maize hybrids for the two field trials in Changsha and Xiangtan were evaluated to investigate grain cadmium content difference under spring and summer sowing conditions in this study.The results showed that the sowing date had a significant effect on cadmium concentration in maize kernels,and the cadmium content in spring was higher than that in summer.There were significant differences and large genetic variation in cadmium concentrations in grains of different maize varieties.The coefficient of variation exceeded 100%and the broad heritability of cadmium concentration was 85%.Correlation analysis showed that the cadmium content in paddy soil was significantly correlated with grain cadmium content and the correlation coefficient was the highest in different sowing dates in the same place.According to cadmium accumulation characteristics,the results showed that’Kangnongyu999’could be regarded as grain high-cadmium accumulation type;’Suyu20’,’Kangnong18’and’Qingqing515’could be regarded as grain moderate-cadmium accumulation type,and the remaining 30 varieties could be regarded as grain low-cadmium accumulation type.Most of the low-cadmium accumulation maize varieties could be considered to be candidate crops for the alternative cultivation in cadmium contaminated farmland.’Kangnongyu999’could be considered to be an ideal research material for the genetic mapping of genes related to cadmium accumulation in grains.