Relationship between salt tolerance and photosynthesis or leaf water potential in several temperate grasses
2001
Maeda, Y. (Tokyo Univ. of Agriculture (Japan)) | Unno, H. | Hirano, S. | Takenaga, H.
Salt tolerance in several temperate grasses was investigated from leaf photosynthetic rate in intact plant, oxygen-evolving activity in isolated thylakoid membrane, leaf water and osmotic potential, and Na, K and free Proline (Pro) contents. Four seedlings derived from commercial seeds (tall fescue ; TF, Italian ryegrass ; IRG, reed canarygrass ; RCG, alfalfa ; ALF), and RCG seedlings grown on soil per fused with cattle urine (P-RCG) and on soil not per fused (C-RCG) were treated with NaCl for 10days. Salt tolerance was the strongest in P-RCG, followed by TF, C-RCG, IRG, RCG and ALF under 100mM NaCl stress. Both leaf photosynthetic rate in intact plants and oxygen production in thylakoid membranes were decreased under a saline condition. Salt tolerance became stronger in the grasses with lower decrease rates of photosynthesis under salt stress. No clear relationship was recognized between change rates in Na, K and free Pro contents of plant tops and decrease rates in leaf osmotic potential. Except for ALF, salt tolerance was stronger in the grasses with lower decrease rates in leaf water potential under salt stress. On the other hand, ALF had the weakest tolerance in spite of showing low decrease rate in leaf water potential, which suggested the direct salt damage caused by ion excess.
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