鹽分對五梨跤(Rhizophora stylosa)苗木形質生長之影響

Effects of Salinity on Morphological Growth of the Mangrove Rhizophora Stylosa Seedlings

10.30064/QJCF.200903.0003

范貴珠(Kuei-Chu Fan)；徐誠宏(Cheng-Hung Shiu)

紅樹林 ； 五梨跤 ； 鹽度 ； 形質生長 ； Mangrove ； Rhizophora stylosa ； Salinity ； Morphological growth

中華林學季刊

42卷1期（2009 / 03 / 01）

41 - 55

繁體中文

本研究探討不同鹽度對五梨跤(Rhizophora stylosa)苗木形質生長之影響，將胎生苗(viviparous seedling)以0、0.75、1.5及3.0% NaCl等4種鹽度處理60、120及150天。研究結果顯示，苗木之形質生長隨著鹽分濃度的增加而降低；其中0.75及1.5 %NaCl處理之新萌芽高、地際直徑、各部位乾物重、總乾重及相對生長速率(RGR)較大；另計算各苗木之品質指數則以0.75% NaCl處理者最大，表示此為適合五梨跤苗木生長之鹽分濃度。而0及3%處理苗木所有形態參數均明顯下降，苗木生長量較小主要是因RGR降低所致。在葉片形態參數方面，0.75及1.5 % NaCl處理苗木之葉片數、總葉面積、葉片伸展速率、肉質程度、葉面積比(LAR)、比葉面積(SLA)及葉重比(LWR)亦較高。而0及3.0%鹽分濃度處理者均明顯降低，顯示鹽分會導致葉部型態及碳分配之改變。

This study examined the effects of salinity on morphological growth of the mangrove Rhizophora stylosa seedlings. The viviparous seedlings were grown in various concentrations of salinity containing 0, 0.75, 1.5, and 3.0% NaCl each for 60, 120, and 150 days. The overall morphological parameters including sprout height, diameter at root collar, dry weight of various components, total dry weight and relative growth rate (RGR) were higher for seedlings that cultivated in 0.75 and 1.5% NaCl. The seedling quality index for seedlings that cultivated in 0.75% NaCl was the highest, indicating that the 0.75% NaCl was the optimum salinity for seedling growth of this species. All morphological parameters of seedlings grown in 0 and 3.0% NaCl were significantly decreased. The results also implied that the growth reduction in R. stylosa was primarily a result of a lower RGR. The leaf numbers, total leaf area, leaf expansion rate, leaf succulence, leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) of the seedlings cultivated in 0.75 and 1.5% NaCl were also higher. However, all leaf morphological parameters for seedlings cultivated in 0 and 3.0% Nacl were significantly decreased, which indicated that leaf morphology and carbon allocation were altered by salinity.