黄柳与垂柳的耐热性和耐旱性比较研究  

A COMPARATIVE STUDY ON HEAT AND DROUGHT TOLERANCE BETWEEN SALIX GORDEJEVII AND SALIX BABYLONICA

作　　者：杨甲定[1] 赵哈林[1] 张铜会[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,兰州730000

出　　处：《植物生态学报》2005年第1期42-47,共6页Chinese Journal of Plant Ecology

基　　金：国家重点基础研究规划发展项目(G2000048704)国家"十五"防沙治沙攻关项目(FS20001)

摘　　要：作为一种优良的固沙植物,黄柳(Salix gordejevii)主要分布于内蒙古科尔沁沙地和浑善达克沙地,在流动沙 丘边缘和半流动沙丘生长最多,属于灌木型先锋植物。实验对黄柳的耐热性和耐旱性与垂柳(Salix babylonica)进行 了比较研究。两种植物的离体叶片在6个温度(即25、30、35、40、45、50℃)下处理1 h;在6个水势梯度(即0、 -0.25、-0.5、-0.75、-1.0、-1.25 MPa)下处理24 h后,测定了其含水量、膜透性、光系统Ⅱ的最大光化学效率 (由Fv/Fm计算)等参数。黄柳叶片在温度处理和干旱处理中均能保持比垂柳较高的含水量;45℃以下的温度对两 种植物叶片的膜透性没有明显影响,但高于45℃的温度(本实验中为50℃)使黄柳和垂柳叶片膜透性剧增,且黄柳 增大更多;干旱处理造成两种植物叶片膜透性增大,且垂柳的总是大于黄柳的;低于35℃的温度对Fv/Fm没有影 响,高于40℃的温度使两种植物叶片的Fv/Fm明显降低,且黄柳的极显著地小于垂柳的;干旱处理总使两种植物 叶片的Fv/Fm降低,当渗透势小于-0.75 MPa时,黄柳的Fv/Fm显著地大于垂柳的。这些结果说明黄柳的耐旱性 比垂柳强,其耐热性比垂柳差。就光合器官而言,黄柳、垂柳耐热性和耐旱性的差别主要是由于通过光系统Ⅱ的电 子传递对高温和干旱的敏感性不同造成的。Salix gordejevii (SG), a useful dune-fixing plant, is a pioneer bush that establishes primarily on the margins of moving sand dunes in Horqin Sand Land and Hunshandak Sand Land, Inner Mongolia, China. In this study, the heat and drought tolerance of SG were examined and compared to S. babylonica (SB) . Leaves removed from the two species were subjected to six temperature treatments (25, 30, 35, 40, 45, 50 ℃) for 60 minutes and six drought treatments (0, -0.25, -0.5, -0.75, -1.0, - 1.25 MPa) for 24 hours. The relative water content, membrane permeability and maximal quantum efficiency of photosystem Ⅱ(PSⅡ) were assayed. Leaves of SG maintained more water during both temperature and drought treatments. Temperature treatments below 45 ℃had no effect on the membrane permeability of either of the two species, but treatments above 45℃ induced much higher electrolyte leakage in SG than in SB. Each drought treatment caused an increase in membrane permeability in both SG and SB but was greater in SB in all drought treatments . Temperatures below 35℃ did not influence maximal quantum efficiency of PSⅡ (measured as Fv/ Fm) in either of the two species, whereas treatments above 40℃ caused Fv/Fm to decrease in both species but was significantly lower in SG. Drought treatments resulted in a decline in Fv/Fm in both species but declines were significantly higher in SG when the osmotic potential was lower than-0.75 MPa. These results suggest that SG has a higher capacity for drought tolerance and a lower capacity for heat tolerance compared to SB. The different stress tolerance between SG and SB was due mainly to different sensitivities of electron transport through PSⅡ to heat and drought.

关 键 词：黄柳 垂柳 耐热性 耐旱性 比较研究 膜透性 叶绿素荧光 固沙植物 

分 类 号：S792.12[农业科学—林木遗传育种]