缺锌条件下小麦的养分吸收状况及不同基因型的耐性差异

Effect of Zn Deficiency on Nutrient Absorption of Wheat and Their Genotypes Difference in Tolerant to Zn Deficiency

采用螯合-缓冲营养液(Chelator-buffer culture solution)进行培养试验,对缺锌条件下3种小麦基因型(绵阳19、邯6172、新麦13)的生长发育状况及对P、Cu、Fe、Mn营养的影响进行了研究,并且应用4种指标,即锌效率(缺锌与锌充足供应条件下小麦地上部干物质之比)、相对冠根比(缺锌与锌充足供应条件下小麦冠根比之比)、缺锌条件下小麦地上部的锌吸收量、干物质量,对3种小麦的耐缺锌能力进行了比较。结果表明,在锌缺乏条件下小麦地上部生长量明显降低,而根系依然能保持相对较强的生长发育能力;不同小麦基因型对缺锌的耐性存在明显差异,其中邯6172的耐性最强;在缺锌胁迫条件下,小麦地上部Cu、Fe、Mn含量及Cu/Zn、Fe/Zn、Mn/Zn均明显升高,地上部锌含量与Cu、Fe、Mn含量均呈极显著负相关,说明锌缺乏能够促进Cu、Fe、Mn在地上部的累积。与此相反,锌缺乏条件下小麦P含量及吸收量均明显降低,地上部磷、锌含量之间极显著正相关,但与Cu,Fe,Mn相似,缺锌后P从根系向地上部的转运率升高。同时,对缺锌耐性最强的小麦基因型邯6172在锌缺乏条件下,地上部Cu、Fe、Mn含量的升高与P含量的降低幅度均是3种供试小麦中最大的,似乎表明小麦对锌缺乏的耐性大小与对Cu、Fe、Mn的吸收能力及与对P吸收的抑制有关。

An experiment with chelator-buffer nutrient solution was conducted to investigate the growth and Cu, Mn, Fe, P nutrition of three winter wheat genotypes （ Mianyang 19, Han 6172 and Xinmai 13 ） under zinc deficiency. Four indices were chosen to characterize the tolerance of wheat plants to Zn deficiency： Zn efficiency, namely, relative shoot weight at low compared to high Zn supply ; relative shoot/root ratio, namely, the ratio of shoot/root ratio at low zinc to high Zn supply ; total shoot uptake of Zn Under Zn deficient conditions ; shoot dry weight under deficient conditions. The results indicated that the shoot growth of wheat plants was decreased obviously, but the root growth can still keep well under zinc deficient conditions. Three wheat genotypes exhibited different tolerance to zinc deficiency, and the Han 6172 was consistently more tolerant than other two wheat genotypes by assessed using all four indices. The Cu, Mn, Fe concentration and the ratios of Cu/Zn, Mn/Zn, Fe/Zn were increased in shoot parts of all three wheat genotypes under zinc deficiency, and there was very significant negative correlations between Cu, Mn, Fe concentration and zinc concentration in shoot of wheat, suggested that it will stimulate Cu, Mn, Fe accumulation under zinc deficiency. On the contrary, the P concentration and uptake in wheat roots and shoots were decreased under zinc deficiency, and the concentrations of P in shoot tissue were positively correlated with Zn concentration, but the translocation ratio to shoots of P was increased under zinc deficiency, this was similar to Cu, Mn and Fe. In addition, the Han 6172 which had more tolerance to zinc deficiency accumulated more Cu, Mn, Fe and less P under zinc deficiency. It is postulated that there existed relation between the tolerance to zinc deficiency of wheat and the increased of Cu, Mn, Fe concentration, as well as decreased of P in shoots under Zn deficiency.