Responses of growth, morphology, and anatomy to salinity and calcium supply in cultivated and wild barley

Abstract

Growth, morphology, and anatomy were examined in cultivated barley (Hordeum vulgare L. cv. Harrington), and wild barley (Hordeum jubatum L.) collected from a wild population located in Saskatoon, Sask. Plants were grown in nutrient solution plus mixed sulphate salts with low or high calcium supply and in nutrient solution alone (control), using a hydroponic system in a growth chamber. Salt stress had greater deleterious effects on growth, morphology, and anatomy of 'Harrington' than wild barley. Additional Ca supply markedly improved these parameters in 'Harrington' but not in wild barley, suggesting a greater responsiveness to Ca in the cultivated species. The wild barley population had greater leaf and tiller numbers per plant but smaller leaf area and dry mass than 'Harrington' in control solution. After 20 days of salt treatment, 'Harrington' showed a greater reduction in tiller and leaf number, shoot height and root length, and tissue dry mass than wild barley. Calcium-deficiency symptoms were found in 'Harrington' leaves in the low Ca salt treatment but not in wild barley. On the other hand, shoot height and dry mass growth were significantly increased in 'Harrington' by high Ca salt treatment, suggesting that 'Harrington' was more responsive to supplemental Ca than wild barley. Salt stress induced thicker roots with larger vessels in 'Harrington' but not in the wild barley population. Key words: calcium nutrition, Hordeum vulgare L., Hordeum jubatum L., hydraulic resistance, salt tolerance, root anatomy, sulphate salinity.