湖南省猕猴桃果园土壤镉含量及镉吸收规律研究

A Study of Soil Cadmium Content and Its Absorption Law in Kiwifruit Orchards in Hunan Province

研究湖南省猕猴桃果园土壤镉元素含量和污染情况,并对猕猴桃植株内的吸收和分配规律进行分析。结果表明,湖南省猕猴桃果园土壤主要受到镉的轻度污染,中、重度污染所占比例只有10.52%,且存在分布不均匀,区域变幅较大的污染特点;38个猕猴桃果园土壤镉含量在0.202~4.9 mg/kg,19个品种的果实镉含量在0~0.027 mg/kg,均远低于食品安全国家标准镉元素污染物的限制值(0.05 mg/kg),探明猕猴桃为果实镉含量低吸收果树;经过变异分析和方差分析,猕猴桃不同部位镉含量由高到低依次为根、茎、叶、果;在同一污染条件下,猕猴桃各器官镉含量由高到低依次为根、茎、叶、果,镉含量在根中的富集系数最大,其次是茎和叶,果中最低;在同一器官中,随着土壤中镉污染等级的升高,猕猴桃各个器官镉的吸收量也随之增加,但各个器官镉的吸收量富集系数逐渐降低。

The study investigated the contents ol soil heavy metals and the pollution status in kiwifruit or-chards in Hunan Province and analysed the law ol cadmium absorption and distribution in kiwilruit plants.The experimental results indicated that the soil in orchards was mostly slightly polluted by cadmium.Medially pollu-ted and severely polluted soil accounted lor only 10.52% , and the pollution showed the characteristics ol the un-even distribution larger regional varying ranges.The soil cadmium contents ol 38 kiwilruit orchards was between 0.202 mg^kg and 4.9 mg^kg,the fruit cadmium contents ol 19 varieties was between 0 mg^kg and 0.027 mg^kg, which were far lower than the national food safety standards ol cadmium pollution limit（0.05 mg^kg,FW） , in- decaring that kiwilruit is a tree ol low-level cadmium absorption.By mutation analysis and variance analysis,the distribution ol cadmium in kiwilruit ranked a s： root〉 stem〉 leal〉 lruit;Under the same pollution condition,the cadmium content in kiwilruit organs was in the order ol root〉stem〉leal〉fruit;the root had the largest accumu-lation coefficient ol cadmium,followed by the stem and leal,lruit had the lowest.The cadmium contents in dif-ferent organs increased with the increase ol soil cadmium pollution degree, but the absorption coefficients ol dillerent organs decreased grudually.