供锌条件下碳酸钙对小麦幼苗生长和锌吸收的影响

Effects of CaCO_3 addition under Zn supply on wheat seedlings growth and Zn uptake.

通过营养液培养试验,研究了供Zn条件下添加CaCO3对3种基因型冬小麦(远丰998、中育6号、小偃22)幼苗生长及Zn吸收的影响.结果表明,供Zn和添加CaCO3对小麦幼苗生长量和根冠比均无显著性影响,3种基因型小麦间亦无显著性差异;添加CaCO3诱发了小麦叶片失绿黄化.无论供Zn还是不供Zn,添加CaCO3对3种基因型小麦根、茎、叶各部分的Zn含量及累积量均无显著性影响;与不供Zn处理相比,供Zn会大幅度地提高根、茎、叶的Zn含量和累积量,供Zn使3种基因型小麦植株Zn含量分别增加80·0%、104·8%和139·6%,缺Zn敏感型小麦远丰998植株Zn含量和累积量的增加幅度远小于不敏感型小麦中育6号和小偃22.供Zn和添加CaCO3对小麦幼苗根、茎、叶中P含量均无显著影响,但远丰998小麦根、茎、叶3部分的P含量均明显低于其它两种非敏感型小麦.供Zn使小麦根、茎、叶3部分的P/Zn大幅度降低,添加CaCO3也使P/Zn呈现降低的趋势.不供Zn条件下添加CaCO3能诱发小麦失绿黄化,但Zn吸收量未降低.表明在水培条件下,高含量CaCO3对小麦Zn吸收并未产生明显的抑制作用.

High concentration calcium carbonate in calcareous soils usually limits plant Zn uptake. In this paper, a solution culture experiment was conducted to study the effects of CaCO3 addition with or no Zn supply on the growth and Zn uptake of three genotypes winter wheat seedlings. The results showed that Zn supply or CaCO3 addition had no significant effects on seedlings biomass and root/canopy ratio, and there was no significant difference among the three genotypes. CaCO3 addition led to leaf chlorosis. No matter with or no Zn supply, CaCO3 addition had no significant effects on the Zn concentration and accumulation in wheat root, stem, and leaf. Zn supply increased the Zn concentration in Yuanfeng 998, Zhongyu 6, and Xiaoyan 22 by 80. 0%, 104. 8% and 139. 6% , respectively. For Yuanfeng 998, a sensitive genotype to Zn-deficiency, the increment of Zn concentration and accumulation was much lower than that of Zhongyu 6 and Xiaoyan 22, non-sensitive genotypes to Zn-deficiency. Zn supply or CaCO3 addition had no significant effects on the P content in root, stem, and leaf, but the corresponding P content of Yuanfeng 998 was obviously lower than that of the other two genotypes. Zn supply greatly decreased the P/ Zn ratio in root, stem and leaf, and CaCO3 addition also showed the same tendency. Under Zn-deficiency, CaCO3 addition caused leaf chlorosis, but did not decrease wheat plant Zn uptake. In conclusion, at least under solution culture condition, high concentration calcium carbonate had no obvious inhibitory effect on plant zinc uptake, and whether this situation was true in calcareous soils is worthy to be further investigated.