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Adequate supply of potassium improves plant water-use efficiency but not leaf water-use efficiency of spring wheat.
- Source :
- Journal of Plant Nutrition & Soil Science; Dec2016, Vol. 179 Issue 6, p733-745, 13p
- Publication Year :
- 2016
-
Abstract
- Enhancing crop water-use efficiency (WUE) is a major research objective in water-scarce agroecosystems. Potassium (K) enhances WUE and plays a crucial role in mitigating plant stress. Here, effects of K supply and PEG-induced water deficit on WUE of spring wheat ( Triticum aestivum L. var. Sonett), grown in nutrient solution, were studied. Plants were treated with three levels of K supply (0.1, 1, 4 mM K<superscript>+</superscript>) and two levels of PEG (0, 25%). WUE was determined at leaf level (WUE<subscript>L</subscript>), at whole-plant level (WUE<subscript>P</subscript>), and via carbon isotope ratio (δ<superscript>13</superscript>C). Effects of assimilation and stomatal conductance on WUE<subscript>L</subscript> were evaluated and compared with effects of biomass production and whole-plant transpiration (E<subscript>P</subscript>) on WUE<subscript>P</subscript>. Adequate K supply enhanced WUE<subscript>P</subscript> up to 30% and by additional 20% under PEG stress, but had no effect on WUE<subscript>L</subscript>. E<subscript>P</subscript> was lower with adequate K supply, but this effect may be attributed to canopy microclimate. Shoot δ<superscript>13</superscript>C responded linearly to time-integrated WUE<subscript>L</subscript> in adequately supplied plants, but not in K-deficient plants, indicating negative effects of K deficiency on mesophyll CO<subscript>2</subscript> diffusion. It is concluded that leaf-scale evaluations of WUE are not reliable in predicting whole-plant WUE of crops such as spring wheat suffering K deficiency. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14368730
- Volume :
- 179
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Journal of Plant Nutrition & Soil Science
- Publication Type :
- Academic Journal
- Accession number :
- 119952607
- Full Text :
- https://doi.org/10.1002/jpln.201600340