[Effect of HCO3- on root growth and nutrient absorption of different rice genotypes].
Solution culture experiments with Zn-inefficient cultivar (IR26) and the Zn-efficient cultivar (IR8192-31-2) were conducted to study the effect of HCO3- on the root growth and nutrient absorption of different rice cultivars. The results showed that HCO3- strongly inhibited the root growth of Zn-inefficient cultivar especially at low Zn concentration. In contrast, that of Zn-efficient cultivar was slightly stimulated by HCO3- at low Zn concentration. HCO3- not only inhibited Zn absorption of Zn-inefficient cultivar, but also inhibited its absorption of Fe, Mn, Cu, implying that there was no specific inhibition of HCO3- on Zn absorption. These results demonstrated that the inhibition of root growth by HCO3- was likely to be the initial action of HCO3- in inducing Zn deficiency in lowland rice. With treatment of bicarbonate, Zn concentrations in upper and lower leaves of the Zn-efficient cultivar and their ratios were higher than those of the Zn-inefficient cultivar. The results showed that the Zn-efficient cultivar could transport more zinc from lower leaves to upper leaves, which might be-one of mechanisms that the Zn-efficient cultivar adapted to zinc deficiency in calcareous soil.
Xu
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Department of Tobacco Science, University of Science and Technology of China, Hefei 230052. xuy@mail.hf.ah.cn
Yang
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Yang
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D000042:Absorption / Q000187:drug effects*; D001639:Bicarbonates / Q000494:pharmacology*; D003300:Copper / Q000378:metabolism; D005838:Genotype; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D012275:Oryza / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects* / Q000502:physiology; D015032:Zinc / Q000378:metabolism
D001639:Bicarbonates; D008345:Manganese; D003300:Copper; D007501:Iron; D015032:Zinc