间作绿豆对核桃苗光合特性及根系导水力的作用  

Effects of Intercropped Vigna radiata on Root Hydraulic Conductance and Photosynthetic Characteristics of Juglans regia Seedlings

作　　者：张翠萍[1,2] 孟平[3] 张劲松[3] 万贤崇[1] 

机构地区：[1]中国林业科学研究院新技术研究所,北京100091 [2]青岛农业大学园林与林学院,青岛266109 [3]中国林业科学研究院林业研究所,北京100091

出　　处：《林业科学研究》2016年第1期110-116,共7页Forest Research

基　　金："十二.五"农村领域国家科技计划(2011BAD38B02)

摘　　要：[目的]为研究间作绿豆对核桃苗根系生长、根系水分运输和光合特性的影响,[方法]采用砂培方法,在温室内将1年生核桃嫁接苗和绿豆进行间作。[结果]显示:间作绿豆增加了土壤全氮含量(0.014%0.021%),不添加氮素间作绿豆,核桃苗根系总表面积、根系总长度、根系直径和根系总体积均显著增加,而正常供应氮素间作绿豆,核桃苗根系生长降低。核桃苗根系单位面积的导水率与土壤氮素含量显著相关,添加氮素与否间作绿豆后,根系单位面积导水率分别升高0.102×10-5m L·cm-1·min-1·MPa-1和0.057×10-5m L·cm-1·min-1·MPa-1;而不添加氮素间作绿豆整株根系导水率增加0.043 m L·cm-1·min-1·MPa-1,正常供应氮素间作绿豆后,核桃苗整株根系导水率反而降低0.034 m L·cm-1·min-1·MPa-1;核桃苗气孔导度对各处理响应和根系整株导水力有相同趋势,不添加氮素间作绿豆核桃光合能力升高至对照水平,光饱和点达1 567.17μmol·m-2·s-1,最大净光合速率达12.84μmol·m-2·s-1,光补偿点和暗呼吸速率降低;而正常供应氮素间作绿豆核桃苗光合能力降低。[结论]间作绿豆改善了核桃苗的生长环境,有益于增加核桃苗的根系吸收面积、水分运输以及光合代谢;但在氮素充足的土壤中,间作绿豆非但无益于核桃苗,反而降低核桃苗的水分供应,影响其气体交换和光合能力。One-year-old Juglans regia seedlings were intercropped with Vigna radiata in greenhouse. The root growth,root hydraulic conductance,and photosynthetic characteristics of J. regia seedlings were measured to explore the effects of V. radiata,a nitrogen fixing crop,on root water uptake and gas exchanges of the intercropped J.regia seedlings. The results showed that with nitrogen deprivation,the nitrogen-fixing V. radiate plantation increased nitrogen content in the soil and improved root growth of J. regia seedlings. However,under abundant nitrogen condition,V. radiata plantation inhibited root growth of J. regia. Nitrogen deficiency significantly reduced the root hydraulic conductivity of J. regia,and the root hydraulic conductivity was significantly positively correlated with nitrogen content in the soil. However,as for whole root hydraulic conductance of J. regia,nitrogen deprivation or high nitrogen（ ordinary nitrogen supply plus V. radiata plantation） significantly inhibited the root hydraulic conductance. Stomatal conductance had the same trend with root hydraulic conductance in response to the treatments.With nitrogen deprivation,the light saturation point decreased,the light compensation point and dark respiration rate increased,the reduction of photosynthetic activity of mesophyll,leading to the decrease of photosynthetic rate.With nitrogen deprivation,the nitrogen-fixing V. radiate facilitated the photosynthetic capacity of J. regia. In summary,with nitrogen deprivation,V. radiate facilitated root growth of the intercropped J. regia seedlings,and improved root hydraulic conductance and hence the leaf photosynthetic ability. However,with nitrogen abundance,V.radiata plantation inhibited root growth of J. regia and the whole root hydraulic conductance,and thus had a negative impact on the leaf photosynthetic ability.

关 键 词：氮素营养 根系生长 根系导水力 光合特性 

分 类 号：S664.1[农业科学—果树学]