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作 者 ：陈玲;田霄鸿;李峰;李生秀

期 刊 ：植物营养与肥料学报 2006年 12卷 4期 页码：523-529

关键词：碳酸钙；锌；小麦基因型；pH；重碳酸根；

Keywords:calcium carbonate, zinc, bicarbonate, wheat genotype, pH,

摘 要 ：以霍格兰营养液为介质,在不同的Zn(0、0.016、0.082.mg/L)与CaCO₃(0、10、306、0.mg/L)用量下,将5种基因型冬小麦进行营养液混合培养,探讨Zn与CaCO₃用量对小麦幼苗生长、Zn吸收及营养液中HCO₃-含量和pH的影响。结果表明,5种基因型冬小麦中,S02-8、远丰998为缺锌敏感型,西杂1号为缺锌非敏感型,适量供Zn比高量供Zn更有利于小麦生长。低量CaCO₃可在一定程度上促进小麦幼苗生长,而高量CaCO₃会抑制生长;缺锌敏感型的生长量显著低于非敏感型,且前者的根冠比小于后者。加入CaCO₃后对各基因型小麦Zn吸收量无显著影响,但随着供Zn量的增加,根系与地上部吸Zn量也随之增加,且高量供Zn时Zn在根部大量累积;缺锌敏感型小麦比非敏感型更易于在根系中累积Zn,而Zn向地上部的转移率远比非敏感型低。与不添加CaCO₃相比,加入一定量CaCO₃后,营养液中HCO₃^-浓度与pH值均有较大幅度上升,并且二者均随着CaCO₃加入量增加而升高。在每10.d更换一次营养液的培养过程中,营养液pH值在一日内的波动范围在0.2个pH值单位内,但pH值总体上随着培养天数推移而呈上升趋势,10.d内上升范围在0.79～2.37个pH值单位;每10.d为一阶段的培养结束后,不同CaCO₃用量间的pH值差异与开始时相比均大大减小。此外,因高量CaCO₃抑制小麦幼苗生长,加剧缺Zn症状,但又不降低Zn吸收量,据此推测,高量CaCO₃可能通过产生较高浓度的HCO₃^-而降低植物体内所吸收的Zn的生理活性。

Abstract:In order to study effects of calcium carbonate(CaCO₃) and zinc(Zn) supplied in the nutrient solutions on the seedling growth and zinc uptake of winter wheat,and bicarbonate concentration and pH value in nutrient solution,five winter wheat genotypes,namely S02-8,Yuanfeng 998,Zhongyu 6,Xiaoyan 22,and Xiza 1,were mix-cultivated in Hoagland nutrient solution in a greenhouse,and micronutrients were supplied by Arnon micronutrient composition except Zn,and Zn was supplied with three levels of 0,0.016,0.082 mg/L as ZnSO₄·7H₂O,and CaCO₃ with four rates as 0,10,30,60 mg/L,respectively.The results showed that,on the basis of their susceptibility to Zn deficiency: S028 and Yuanfeng 998 could be classified the susceptibility-types,and Xiza 1 were non-susceptibility types.Rational supplying of Zn was favorable for the growth of wheat;Application of CaCO₃ with low rates could promote the development of wheat to some extent,whereas,excessive application of CaCO₃ inhibited the growth of wheat.The biomass yield and ratio of root to shoot of susceptibility wheat were significantly lower than that of non-susceptibility one.Application of CaCO₃ had no significant influence on Zn uptake of wheat,but Zn uptake by roots and shoots of wheat plants increased with(increasing) Zn rates,and Zn was largely accumulated in the roots at the high rate of zinc supply;In addition,wheat plants of susceptibility types were more prone to accumulate zinc in roots than non-susceptibility wheat,and the Zn translocation rate of the former from root to shoot was much lower than that of the latter.Increased both HCO₃^- concentration and pH significantly with increasing rate of CaCO₃ application.Under the condition of exchanging the nutrient solution with 10 day interval,the variation of nutrient pH was ranged within 0.2 pH unit during a day;however,pH of nutrient solution showed an increasing tendency with the proceeding of the cultivation and pH increased in the range of 0.79 to 2.37 within 10 days.At the end of culture,the pH differences between the treatment with various CaCO₃ additions was much less pronounced than that at the beginning of culture.In addition,CaCO₃ addition with high rate inhibited the growth of wheat seedlings,and exacerbated the zinc deficiency symptoms,but it did not decrease the zinc uptake rate,therefore,we could speculate that high rate of CaCO₃ could decrease the physiological activity of Zn taken up in the plants through the induced high concentration of HCO₃^-.

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