果树叶片中不同形态铁含量与失绿黄化病关系研究

对果树叶片中全量铁、HCl提取铁和Fe~(2+)含量分析结果表明:果树黄叶中含有与正常绿叶一样多甚至高于绿叶的全量铁,但用HCl提取的铁和Fe~(2+)的数量则明显比绿叶少。在绿叶中全量铁和HCl提取铁的比率保持着一定的稳定平衡,在桃叶中全量铁/酸提取铁比率大约是2.1。失绿黄叶由于活性铁减少而使比率增大,从而使植株中铁营养代谢失调。因此,全量铁/酸提取铁比率能较好地反映植株铁营养状况。在失绿黄叶中K和P比绿叶高,而Ca含量低,K和Fe成显著负相关。当桃树施用钾肥时,叶子中K~+浓度增加而Fe减少,使K/Ca和K/Fe比显著增大。

STUDY ON THE RELATIONSHIP BETWEEN THE RATIO OF VARIOUS FORMS OF IRON AND CHLOROSIS IN FRUIT PLANT LEAVES

A analysis results of total iron and HCl extractable iron and Fe~(2+) in fruit plant leaves showed that in yellow leaves were as much total iron or even higher amounts than in green leaves. But HCl extractable iron and Fe~(2+) in yellow leaves were significantly less than in green. It was found than the ratio of total iron (Fe_T) and HCl extractable iron(Fe_H) kept stable equilibrium in green leaves and was about 2.1 in peach leaves. As HCl extractable iron decreased in yellow leaves, Fe_T/Fe_H ratio increased and occured disorder of iron metabolism in plants. Thefore, Fe_T/Fe_H ratio in leaves is a better indicator to evaluate the iron nutrition status of the plant. K and P were higher and Ca was lower in yellow leaves than in green. There was significantly negative correlation between K and Fe, which K~+concentration in leaves increased when applied potassium feitilizer to the peach trees, while Fe content decreased in leaves, as a result K/Ca and K/Fe ratios significantly increased.