利用螯合–缓冲营养液对小麦苗期磷–锌关系的研究

采用螯合缓冲营养液培养技术（Chelator-buffer culture solution），对小麦幼苗植株的磷锌营养进行了探讨。结果表明，高磷条件下小麦出现的缺锌黄化与磷中毒症状之间存在着明显区别，本研究结果支持高磷条件下作物出现的黄化是锌缺乏症状而非磷中毒的观点。与缺磷相比，正常供磷促进了小麦的生长，但过量磷对小麦生长有阻碍作用，而且锌的供应加剧了促进或抑制的程度。正常供应磷、锌条件下，小麦幼苗根系或地上部的磷、锌含量、吸收量及转运率均处于相对较高的水平，其余各处理则因为磷或锌供应量不适宜而使植株的磷、锌营养受到不同程度的影响。另外，磷锌相互拮抗的作用方式及大小程度不同:磷主要影响小麦根系对锌的吸收，而锌对小麦磷营养的影响主要是通过对其从根系向地上部转运的抑制来实现的；磷对锌的影响要明显大于锌对磷的影响，磷素水平在小麦的磷、锌营养平衡中起着更为重要的作用。磷锌拮抗作用只在双方供应不适宜的情况下发生，而且相互作用的方式及程度存在明显差异。

Study on P-Zn interaction of wheat using chelator-buffer solution culture technique

An experiment using chelator-buffer nutrient solution was conducted to investigate the interaction of P and Zn nutrition of wheat plants. Zinc rates were supplied at two levels of deficient (0 μmol/L) and normal (3 μmol/L), and P was designed in three rates, namely, 0 (insufficiency), 0.6 (normal), 3(excess) mmol/L. Results showed that excessive P supply to nutrient solution led to zinc deficiency of wheat seedling, and typical Zn-deficiency symptoms occurred: interveinal chlorosis developed between the mid-vein and leaf margin of little leaves; while the tip, base and margins remained green. The wheat plants showed slight P toxicity under high P and no zinc addition: developed yellow chlorotic and necrosis of the tip and margins of old leaves. It is said that high P concentration induces zinc deficiency, but not P toxication. The growth of wheat was increased under normal P supply, but there would be depressed if excess P addition to culture solution, and it was more severe under Zn addition. The zinc, phosphorus uptake by wheat plants and translocation from roots to shoots under normal P was larger at Zn supply than that of any other treatments in which zinc and phosphorus was in the status of deficiency or excessive supply. Moreover, the interaction between P and Zn for each other was different: firstly, as far as the ways of P-Zn reaction, the effect of P on Zn nutrition of wheat was done through decreasing uptake of Zn from the growth medium; however, the effect of Zn on P nutrition of wheat was mainly inhibition of P translocation from roots to shoots; Secondly, the degree of P-Zn antagonism was different: The effect of P to Zn was more obvious than Zn to P, maybe it was because plant needs more P than Zn. It is concluded that the way and degree of P-Zn antagonism was different, and it only occurred under zinc and phosphorus was in the status of deficiency or excessive supply.