摘要
对湿地匍灯藓〔Plagiomnium acutum(L indb.) T.Kop.〕、大羽藓〔Thuidium cymbi-folium(Dozy &Molk.) Dozy &Molk.〕和垂藓〔Chrysocladiun retrorsum(Mitt.) Fleisch.〕的水分含量与光合作用、呼吸作用和水势的关系进行了初步研究 (1 999年 5月 2 0日到 6月1 0日 )。在这 3种藓类植物中 ,其水分含量与光合作用速率 (Pn)的关系可以分为 2种类型 :一种类型如大羽藓和垂藓 ,在藓体水分含量 2 0 %～ 70 %时 ,Pn随着水分含量增加而增加 ,但是在 80 %～ 95%时 ,Pn随水分含量增加而下降 ,光合最适水分含量约 70 %～ 80 % ;另一种出现在湿地匍灯藓 ,水分含量 2 0 %～ 80 %时 ,Pn随着水分含量增加而增加 ,在 80 %～ 95%时 ,Pn维持一个较高的水平 ,光合最适水分含量为 80 %～ 90 %。在一个大的水分含量范围内 (60 %～ 95% ) ,暗呼吸 (Rd)保持相对稳定 ,但是在水分含量较低时 (2 0 %～ 70 % ) ,Rd随着水分含量的下降而下降。在藓体水分含量与水势之间的关系方面 ,3种藓类植物相似 ,水分含量与水势对数之间的回归曲线为
The relationships of water content to photosynthesis, respiration and water potential in three species of mosses, Plagiomnium acutum (Lindb.) T.Kop., Thuidium cymbifolium (Dozy & Molk.) Dozy & Molk., and Chrysocladiun retrorsum (Mitt.) Fleisch. were studied during May 20 to June 10, 1999. Among these three mosses, there are two types of water response models for net photosynthetic rate (Pn). One appeared in Thuidium cymbifolium and Chrysocladium retrorsum , in which Pn increased with the water content from 20% to 70%, but decreased from 80% to 95%. The optimum water content was 70%～80%. Another was presented in Plgiomnium acutum , in which net Pn increased with water content increasing from 20% to 80%, and a high level of Pn maintained from 80% to 95% of water content. The optimum water content was 80%～90%. In a wide range of water content from 60(70)% to 95%, the Rd remained relatively stable. But in the range of lower water contents from 20% to 70%, the Rd decreased with decreasing water contents.Changes in between water contents and water potentials within these three mosses are similar to each other. The whole curve of water contents to logarithm of water potentials appears to be S formed.
出处
《武汉植物学研究》
CSCD
2001年第2期135-142,共8页
Journal of Wuhan Botanical Research
关键词
藓类
光合作用
呼吸作用
水分含量
水势
Mosses
Photosynthesis
Respiration
Water content
Water potential
