盐胁迫对落羽杉生理及生长的影响

Effects of Salinity on Growth and Physiology of Bald Cypress Seedlings

采用盆栽土培试验,对落羽杉(Taxodiumdistichum)在钠盐(NaCl)胁迫下所产生的生理和生长反应进行了研究。盐处理浓度分为4种水平,即NaCl占土壤干重的0.00%,0.15%,0.30%,0.45%,测定指标包括苗高、地径、水势、相对含水量、相对水分亏缺、组织密度、叶绿素含量、质膜特性、脯氨酸含量和蛋白质含量等。结果表明:(1)随盐浓度的提高,落羽杉苗高和地径生长逐渐降低,其中在0.30%和0.45%两种处理下,苗高和地径生长量仅为对照的38.3%和59.1%,52.1%和69.9%,达到了显著性差异水平;(2)随着盐浓度的增加,落羽杉体内叶片脯氨酸含量、质膜特性、组织密度和相对水分亏缺均逐渐上升,而水势、叶绿素含量、可溶性蛋白质的含量、相对含水量等均呈下降趋势;(3)测定的各项生理指标与落羽杉高、径生长量之间的相关系数分别达0.834和0.850以上,说明这些指标与高、径生长量之间关系密切。

In greenhouse,oneyearold seedlings of bald cypress(Taxodium distichum L.)grown in pots containing soils were subjected to salinity(NaCl) treatments.Salinity level is 0.00%,0.15%,0.30% and 0.45% of soil dry weight.After eight weeks of treatment,height growth,diameter growth,leaf water potential,leaf relative water content,leaf relative water deficiency,tissue density,chlorophyll content,relative membrane permeability,free proline content and protein content were determined.The results were as follows:(1)With the increasing of salinity concentration,the height growth and diameter growth decreased,especially the treatments of 0.30% and 0.45% decreased significantly,and the height growth of the two treatments is only 38.3% and 59.1% of control treatment,and the diameter growth is 52.1% and 69.9% of control treatment;(2)With the increasing of salinity concentration,proline content,membrane permeability,tissue density and relative water deficiency decreased gradually,but water potential,chlorophyll content,protein content and relative water content increased;(3)The relation between the physiological indexes determined and the growth of height and diameter is very close,and their relative coefficients are all more than 0.834 and 0.850.