黑河中游边缘绿洲湿润和干旱条件下棉花叶片光合特性比较  

Photosynthetic Characteristics of Cotton Leaves under Different Soil Moisture Conditions in Marginal Oasis Regions of Middle Reach of Heihe River Basin

作　　者：解婷婷[1] 苏培玺[1] 张岭梅[1] 严巧娣[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所临泽内陆河流域研究站极端环境生物实验室,兰州730000

出　　处：《西北植物学报》2009年第1期128-135,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：中国科学院西部行动计划项目(KZCX2-XB2-04);国家自然科学基金资助项目(40471046)

摘　　要：在甘肃河西走廊中部黑河中游临泽北部边缘绿洲区,测定了湿润和干旱条件下早熟陆地棉(Gossypium hirsutum L.)品种‘新陆早8号’棉花叶片的气体交换参数及叶绿素荧光参数动态日变化。结果表明:(1)不同土壤水分条件下棉花叶片均出现"光合午休"现象,但均未出现光抑制;干旱条件下引起棉花"光合午休"以非气孔因素为主,湿润条件下非气孔因素和气孔因素先后共同起作用。(2)干旱条件下棉花叶片净光合速率(Pn)在8:00～11:00高于湿润条件下,且均值提高10.5%,而其在12:00～18:00低于湿润条件下,且均值降低16.5%;干旱条件下叶片Pn和蒸腾速率(Tr)日均值(8:00～18:00)分别比湿润条件下降低4.9%和26.1%,水分利用效率(WUE)却提高了23.4%且达到显著水平。(3)不同土壤水分条件下棉花叶片PSⅡ最大光化学效率(Fv/Fm)都于14:00达全天最低值,但最低值均大于0.80。研究发现,湿润土壤条件并不能消除棉花的"光合午休"现象;干旱土壤条件也未使棉花出现光抑制,却使一定时段的水分利用效率显著提高。Diurnal course of gas exchanges and cholorophyll fluorescency were used to study the mechanism of photosynthetic regulation under different soil moisture conditions for cotton （Gossypiurn hirsuturn L. ） growth in the marginal oasis regions of northern part of Linze in middle reach of Heihe River Basin in the middle region of Hexi Corridor in northwestern China. The results showed that.. （1）There was typical mid- day depression of photosynthesis but no photoinhibition phenomenon or cotton leaves both in moist condi- tion and in arid condition. The reduction of midday photosynthetic rate was mostly caused by non-stomatal factors in arid condition, while in moist condition by both non-stomatal factors and stomatal factors. （2） From 8：00 to 11.00,Pn of cotton leaves in arid condition was higher than that in moist condition,with the average value raising 10.5 % ;but Pn lower than that in moist condition from 12.00 to 18.00,with the ave.r- age value reducing 16.5%. The daily average P, and Tr in arid condition was lower than that in moist condition,reducing 4.9 % ,26.1% ;while WUE raise 23.4 % . The statistical analysis showed significant difference in WUE values between different soil moisture conditions. （3）The lowest value in Fv/Fm appeared at 14：00 and it is larger than 0.8 in both moist condition and arid condition. This study suggested that midday depression of photosynthesis phenomenon of cotton is not avoided in high soil moisture. And cotton pho- toinhibition phenomenon does not occur in low soil moisture. The heavy drought is advantageous in enhan- cing cotton water use efficiency while photosynthesis rate reduced little.

关 键 词：光合特性 光合午休 光抑制 水分利用效率 棉花 

分 类 号：Q945.79[生物学—植物学]