Ion amount in Zoysia matrella Merr. leaves during the winter season in the saline environments

The purpose of the present study was to evaluate the ion amounts characteristics of green leaves and brown leaves in Zoysia matrella (L.) Merr. during the winter season in the saline environments. Plants were treated with four concentrations of NaCl solution (0, 7.5, 15 and 30 g/L NaCl) for 165 days during the winter season. In the 30 g/L NaCl group, all leaves turned brown (leaf mortality ratio was 100％). In the 7.5 and 15 g/L NaCl groups, Na＋ amounts of brown leaves were 1.4-fold and 2.0-fold higher than in green leaves, respectively. Furthermore, in the 7.5 and 15 g/L NaCl groups, Cl－ amounts of brown leaves were 1.4-fold and 2.0-fold higher than in green leaves, respectively. However, K＋ amount exhibited an inverse relationship, with higher K＋ amount in green leaves than in brown leaves. In the 0, 7.5, and 15 g/L NaCl groups, K＋ amounts of green leaves were 2.3-fold, 1.8-fold, and 1.8-fold higher than in brown leaves, respectively. Furthermore, the results of K＋/Na＋ ratio in the green leaves showed higher value compared with brown leaves with significant difference in 7.5 g/L (2.4-fold higher) and 15 g/L (3.5-fold higher) NaCl treated groups. From the results of completely different traits in ion amount and K＋/Na＋ ratio in green and brown leaves indicated that Z. matrella could accumulate harmful NaCl in senescing leaves against salinity stress in the winter season.