Salinity tolerance of Lumnitzera racemosa

• Main Authors: Ren-Jenq You, 游仁正
• Other Authors: Bor-Hung Sheu
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/94931195629288598356

碩士 === 國立中興大學 === 森林學系 === 87 === Summary The objective of this study was to monitor allocation of Cl- and Na+ in Lumnitzera racemosa at Chiguu, Tainan. The results showed that this species could survive in high salinity environment and accumulate a large amount of Cl- and Na+. The amount of Cl- and Na+ in organs decreased as follows: leaf > root > shoot. Cl- and Na+ concentrations of older leaves were higher than those of younger leaves. The lower leaves had more Cl- and Na+ contents than upper leaves, but it was completely reverse in shoots and stems. Cl- and Na+ contents in leaves was negatively correlated with precipitation. But the salinity of leaves was positively correlated with the amount of fallen leaves. It indicated that Lumnitzera racemosa could survive in high salinity by accumulating salt ions in older leaves and excluded with fallen leaves. The K+ concentration decreased with age, but for Ca2+, it was opposite. The Mg2+ concentration was not significantly different between older and younger leaves. The ratio of Ca2+/Na+, Mg2+/Na+, and K+/Na+ increased with age. Stomatal conductance, transpiration, xylem water potential, and leaf water potential of Lumnitzera racemosa were lower than those of general plants, which indicated it could better adapt to high Cl- and Na+ concentrations than non-halophytes in saline environment.