土壤 pH 值对3个牡丹品种的生长及光合特性的影响1）

摘要

With three years old grafted varieties of Paeonia suffruticosa‘Bingshancangyu’ ‘Jinchengnvlang’ and‘Zhoumeigui’ as materials, we studied the effect of soil pH on growth and photosynthetic characteristic .At soil pH of 4.5 and 5.5, many indexes of three varieties including height increments , current branch length increments , leaf area, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), water use efficiency (WU,E), chlorophyll a (chla), chloro-phyll b ( chlb) and chlorophyll a+b ( chla+b) were significantly decreased .The values of intercellular CO 2 concentration ( Ci ) and chla/b were remarkably increased , which indicated that non-stomatal limitation was the main reason for the re-duction of Pn .Under the alkaline stress at soil pH of 9.5, the decrease in Pn of variety‘Bingshancangyu ’ was mainly lim-ited by non-stomatal factors.After treatment, the main role of stomatal factors in the reduction of Pn was replaced by non-stomatal factors.The suitable soil pH range for three varieties growth is in 6.5-8.5.The variety‘Zhoumeigui’ has the wi-dest range of soil pH for the growth , followed by the varieties of ‘Jinchengnvlang ’ and‘Bingshancangyu ’.%采用盆栽方法研究了不同土壤pH值对3年生牡丹嫁接苗‘冰山藏玉’‘金城女郎’和‘绉玫瑰’3个品种的生长及光合特性的影响。结果表明：pH值4．5、pH值5．5显著降低3个品种的株高生长量、当年生枝生长量、叶面积、净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）、水分利用效率（WU，E）、叶绿素a、叶绿素b、叶绿素（a＋b），而显著提高细胞间隙CO2摩尔分数（Ci）、叶绿素a／叶绿素b的值，表明非气孔因素是酸胁迫下3个品种Pn 下降的主要原因；pH值9．5碱胁迫下，‘冰山藏玉’ Pn 下降受非气孔因素限制，而‘金城女郎’和‘绉玫瑰’由处理前期的气孔因素转变为后期的非气孔因素占主导地位。3个品种适宜生长在pH值6．5～8．5土壤环境中，三者对土壤pH值的适应范围由大到小的排序为‘绉玫瑰’、‘金城女郎’、‘冰山藏玉’。