水分胁迫对黄连木、清香木幼苗的影响

人为模拟干旱条件下 ,研究了黄连木、清香木幼苗的叶片相对含水量 (RWC)、荧光和光合色素的变化情况 ,同时对胁迫后期两树种幼苗的生存率也进行了调查分析 .结果表明 :①水分胁迫前期 ,两树种幼苗叶片的相对含水量(RWC)、Fv Fm 相对值和F0 相对值变化缓慢 ,水分胁迫后期 ,两树种幼苗叶片的相对含水量、Fv Fm 相对值迅速下降 ,F0 相对值迅速上升 ,但清香木幼苗叶片相对含水量和Fv Fm、F0 相对值指标变化的速率明显慢于黄连木幼苗 .②轻中度水分胁迫对光合色素影响不明显 .严重水分胁迫时 ,黄连木的Chla ,Chl含量显著下降 ,Chla Chlb比值发生明显减小 (P =0 0 5 ) .③水分胁迫后期 ,黄连木幼苗叶片出现萎蔫和枯黄症状要早于清香木 ,萎蔫枯黄总数占实验材料总数的比例也最高 .以上结果揭示清香木幼苗比黄连木幼苗更耐水分胁迫 .

Effects of water stress on photosynthetic pigment and chlorophyll fluorescence and the survival rate of seedings of Pistacia chinensis and Pistacia weinmannifolia

Under the artificial arid condition, the changes of the relative leaf water content,the chlorophyll fluorescence and photosynthetic pigment content of Pistacia weinmannifolia and Pistacia chinensis were studied. At the same time the survival rate of seedings of these two tree species was investigated.①During the slight water stress period,the changes of leaf relative water content, F v/ F m and F\-0 relative values were slow.Instead,they have markedly changed during the severe water stress period. ②During the slight water stress period the contents of Chla,Chlb, Chl,Car and Chla/Chlb were not affected for seedings of these two tree spieces,during the severe water stress period the contents of Chla,Chl and Chla/Chlb dramatically declined( P =0 05).③ At the end of the drying experiments, Pistacia chinensis showed atrophy and wither symptom earlier than \%Pistacia weinmannifolia\% did, at the same time the ratio of the total of atrophy and wither account for the total of experimental material was the highest.The results show that the seedings of Pistacia chinensis are more tolerant to water stress than Pistacia weinmannifolia.