干旱胁迫对6个树种叶片光合特性的影响

以鄂西红豆(Ormosia hosiei Hemsl.et Wils)、红叶石楠‘红罗宾’(Photinia×fraseri‘RedRobin’)、木荷(Schima superba)、榉树(Zelkova schneideriana)、苏柳172(Salix×jiangsuensis cv.‘J172’)、紫叶李‘好莱坞’(Prunus cerasifera‘Hollywood’)6个树种为研究对象进行干旱胁迫盆栽试验,比较各树种光合特性对干旱胁迫的响应差异。结果表明,干旱胁迫10 d内6树种光合特性对干旱的响应差异明显,紫叶李‘好莱坞’和苏柳172对干旱胁迫较为敏感,干旱胁迫10 d后光合水平显著下降,气孔限制为主要因素。榉树在处理第4天光合的下降由气孔限制引起,但第10天测定结果显示恢复正常。而鄂西红豆、木荷、红叶石楠‘红罗宾’在10 d胁迫期间未受气孔限制。比较正常灌溉水平下3个时点各树种的Ci/Ca平均值,干旱胁迫10 d内抗旱性表现从强到弱排序为:鄂西红豆、木荷、榉树、红叶石楠‘红罗宾’、苏柳172、紫叶李‘好莱坞’。

Effect of drought stress on photosynthetic characteristic of six tree species

Six tree species(Ormosia hosiei Hemsl.et Wils,Photinia×fraseri ’Red Robin’,Schima superba,Zelkova schneideriana,Salix×jiangsuensis cv.’J172’,Prunus cerasifera ’Hollywood’) were conducted to compare the difference of photosynthetic characteristic and drought resistance.Results showed that there were great differences of photosynthetic characteristics of these six tree species during 10 d drought stress period.Photosynthesis of Prunus cerasifera ’Hollywood’ and Salix jiangsuensis cv.’J172’ were much more sensitive to drought stress,of which there were significant decline of photosynthesis after 10 d drought stress due to stomatal limitation.In Zelkova schneideriana,stomatal limitation appeared after 4 d drought stress,however,the photosynthesis level return to normal level in the 10th day.In contrast,there was no stomatal limitation in Ormosia hosiei Hemsl.et Wils,Photinia fraseri ’Red Robin’ and Schima superba during drought stress period.According to the Ci and Ca ratio of six tree species of normal irrigation during the 10 d period,the drought resistant ability arranged in descending order was Ormosia hosiei Hemsl.et Wils,Schima superba,Zelkova schneideriana,Photinia fraseri ’Red Robin’,Salix jiangsuensis cv.’J172’,Prunus cerasifera ’Hollywood’.