不同品种辣木中微量元素的分布特征

为研究不同品种辣木中铁、锰、铜和锌等微量营养元素的分布特征，对西双版纳不同树龄的‘多油辣木’、‘狭瓣辣木’和‘PKM1 辣木’，在不同采收时期不同采收部位中的4 种微量元素含量进行分析比较。结果表明：对于不同种类品种、树龄和采收季节，在辣木的嫩梢和老梢中微量元素的含量有较大差异。不同品种辣木中微量元素含量总体呈现：铁＞锰＞锌＞铜的趋势；叶中铁含量低于茎，锰和锌含量高于茎；辣木嫩梢铁、锰和铜含量低于老梢，锌含量高于老梢。铁和锌含量为：‘多油辣木’和‘PKM1 辣木’>‘狭瓣辣木’，锰含量为：‘狭瓣辣木’>‘多油辣木’和‘PKM1 辣木’，随辣木树龄的增加铁含量呈增加趋势，锰和锌含量呈下降趋势。铁和锌含量夏季低于冬季，锰含量夏季高于冬季。铜含量随品种、树龄和季节变化差异较小。

Distribution Characteristics of Microelements in Different Moringa Varieties

The paper aims to analyze the distribution features of microelements in different ages as well as different harvest periods and organs (leaves, stems, shoots) of three varieties of Moringa in Xishangbanna (e.g, Moringa oleifera, Moringa stenopetala and Moringa PKM1). The results revealed that: there were significant differences of microelements content in young shoots and old shoots of different varieties, ages and harvest periods. In all varieties, iron (Fe) showed the highest content, followed by manganese (Mn) and zinc (Zn), while copper (Cu) content was the lowest. The content of Fe in leaves was lower than that in stems, however the content of Zn and Mn was higher in leaves than that in stems. The microelements contents in young shoots were higher than that in old shoots except Zn. As regard to different varieties, Moringa oleifera had the highest Zn and Fe content, followed by Moringa PKM1 and Moringa stenopetala. Moringa stenopetala had the highest Mn content, followed by Moringa oleifera and Moringa PKM1. Interestingly, the Fe content of Moringa spp increased progressively with the tree age increase, but Mn and Zn content declined. Fe and Zn content were lower in summer, but Mn content was lower in winter. The difference of Cu content of different varieties, ages and harvest periods was not significant.