摘要
以盆栽棉花 (中棉 2 3号 )做为供试材料 ,通过人工遮荫 ,设计了 3种遮荫水平 (不遮光 (CK ) ,遮光 75 %(DN) ,遮光 40 % (SN )和高、中、低 3种水分组合处理 ,其土壤含水量分别为田间持水量的 85 %～ 10 0 % (高水分 ,HW )、65 %～ 85 % (中水分 ,MW )和 45 %～ 65 % (低水分 ,LW ) 探讨了土壤水分和遮荫水平共同作用对棉花苗期至蕾期中午的气孔导度、净光合速率、蒸腾速率和叶水势等的影响 高水分下 ,DN和SN的气孔导度比对照分别增加 16 69%和 2 8 0 1% ,净光合速率分别减少 45 74%和 2 0 5 4% ,中水分下 ,DN和SN的气孔导度分别增加2 8 86%和 2 3 2 8% ,净光合速率分别减少 3 1 97%和 1 64 % ,低水分下三者气孔导度没有显著差异 ,但DN和SN的净光合速率比对照分别减少 46 2 2 %和 13 45 % ;相同水分条件下 ,DN和SN的气孔导度不存在显著差异 ,但DN和SN的净光合速率差异显著 (低水分下除外 ) 回归分析表明 ,气孔导度随叶 -气水汽压差 (VPD)的增加而下降 ,且与净光合速率表现出较弱的相关性 土壤不分与遮荫水平对叶片蒸腾速率和叶水势的影响很小 ,CK、DN和SN之间不存在显著差异 除中水分下SN的胞间CO2 浓度 (Ci)与对照相比没有显著变化外 。
The effects of different soil moistures and shading levels on stomatal conductance(G\-s),net photosynthetic rates(P\-n),transpiration and leaf water potential (LWP) of cotton (variety Zhongmian No.23) grown in pots from the seedling to flower bud stages in summer noon were evaluated.We designed three shading levels:no shading(CK),75% shading (DN) ,40% shading(SN);and three soil moistures:85～100%(high water,HW),65%～85% (mediun water,MW)and 45%～65%(low water,LW)of field water bolding capacity.The G\-s of DN and SN increased by 16.69% and 28.01% compared with CK at HW,respectively,while the P\-n of DN and SN declined by 45.74% and 20.54%,respectively.The G\-5 of DN and SN enhanced by 28.86% and 23.28% compareds with CK at MW,respectively,while the P\-n of DN and SN decreased by 31.97% and 1.64%,respectively.The G\-s of CK,DN and SN did not exhibit significant differences at LW,while P\-n of DN and SN reduced by 46.22% and 13.45%,respectively.Significant difference in G\-s did not exist between DN and SN at the same soil moisture,but there was significant differnece in P\-n between them (except at LW).It was suggested that G\-s declined with the increasing of leaf-to-air vapor pressure difference(VPD) and showed weak correlation with P\-n by regression.The combined effects of soil moistures and shading levels on LWP and transpiration rate were not significant.There was no significant difference in LWP and transpiration rate among three shading treatments.Contrasted to treatment CK,intercellular CO\-2 concentration (C\-i) in DN and SN at HW,MW and LW increased significantly,except no arrarent change of C\-i in SN at MW.
出处
《应用生态学报》
CAS
CSCD
2000年第3期377-381,共5页
Chinese Journal of Applied Ecology
基金
国家杰出青年基金资助项目!(4972 51 0 1 )
