Varietal variation in uptake and utilization of potassium (rubidium) in high-salt seedlings of barley |
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Authors: | PAUL JENSÉ N,SUNE PETTERSSON |
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Affiliation: | Department of Plant Physiology, University of Lund, Sweden, Box 7007, S-220 07 Lund, Sweden |
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Abstract: | Seedlings of eleven varieties of barley (Hordeum vulgare L.) showed differences in utilization of K+ from a full nutrient solution containing 3.0 mM K+. The K+ content of both roots and shoots was proportional to the fresh weights and dry weights after a week in the nutrient solution. The K+ use-efficiency ratio, which indicates the efficiency of nutrient utilization (mg dry weight produced per mg K+ absorbed), differed significantly among the varieties. There was no correlation between influx of Rb+ and the content of K+. It is suggested that there are wide varietal differences in such genetically-determined properties as ion influx and efflux and net ion transport to the shoot. Further-more, the influx of Rb+ was closely linked to transpiration, probably due to a variety-specific non-metabolic part of Rb+ influx. Varietal differences in influx of Rb+ were more pronounced in high-K+ roots than in low-K+ roots with maximum rate of Rb+ uptake, but the rank of varieties was the same in each case. – Criteria for the selection of K+ use-efficient varieties of barley are discussed. |
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Keywords: | Barley variety K+-content Rb+-influx K+-efflux K+ use-efficiency ratio transpiration |
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