Abstract
The effects of calcium (6 and 12 mM) supply on plant growth, Na, K and Ca uptake of unstressed (0 mM NaCI) and stressed (75 mM NaCI) wheat seedlings (Triticum aestivum cv. Sarsabz) were investigated. Shoot dry matter production was significantly (p < 0.05) lower (58%) at 75 mM NaCllevel than that at control. Elevated calcium (12 mM) supply to the root medium enhanced shoot growth by 36% as compared to control. Similarly 53 % reduction in root dry matter yield was recorded at 75 mM NaCI and 43 % yield increase was noted at 12 mM Ca level. At 75 mM NaCI + 12 mM Ca level, there was 17 % less sodium accumulation in shoot tissues as compared to 75 mM NaCI + 6 mM Ca level while 27% reduction in Na concentration in root tissue was observed at 12 mM Ca as compared to 6 mM Ca level. Relatively higher calcium supply (12 mM) to the root medium resulted in 20 % more K concentration. At 75 mM NaCI, 40% reduction in K concentration was found in shoot tissue as compared with control. In root tissue, 12 mM calcium supply enhanced K concentration by 58 % as compared to 6 mM calcium level at both salinity levels. A significant positive correlation (r=0.99) between shoot calcium content and corresponding dry matter yield indicated a positive role of calcium for increasing dry matter yield. Similarly, significant positive correlation (r=0.99) between shoot K and shoot dry matter yield was noticed exhibiting high K accumulation with the increasing dry matter yield. However, a negative correlation (r= - 0.95) between shoot dry matter yield and sodium content in shoot, is indicative of growth inhibition due to increasing sodium contents in shoots.
