水分胁迫和种源对黄柳叶功能性状的影响

Effects of Water Stress and Provenance on Leaf Functional Traits of Salix gordejevii

【目的】比较分析水分胁迫、种源及其交互作用对不同种源黄柳叶功能性状的影响,并探讨种源地气候与种源差异的关系。【方法】采用盆栽水分梯度法,选取来自6个种源地的当年生黄柳扦插苗为试验材料,设置正常水分(CK)、轻度干旱(T1)、中度干旱(T2)和重度干旱(T3)4个水分胁迫梯度,利用Li-Cor6400便携式光合作用测定系统测量苗木的光合指标,在Arc Gis9.2中从World CLIM全球高分辨率(1 km×1 km)气候数据库中提取出各种源地的气候数据,并以此计算年平均降水量(MAP)和年平均气温(MAT),用ANOVA分析不同种源黄柳叶功能性状对不同水分胁迫处理的响应,结合一般线性模型(GLM)分析源地气候、种源和水分胁迫对黄柳叶功能性状的影响,并用Pearson相关性分析种源地气候因子(MAT,MAP)与叶功能性状的相关关系。【结果】1)水分胁迫对黄柳的净光合速率(Pn)、蒸腾速率(E)、水分利用效率(WUE)和相对含水量(RWC)有显著影响。2)种源对所有性状都有显著影响,但对不同性状的影响不同。对Pn和E,种源的作用相对于水分胁迫的作用很弱;对WUE和RWC,种源主要是通过影响二者对水分胁迫的响应方式起作用;比叶面积(SLA)主要受种源影响,对水分胁迫不敏感。3)种源地气候对Pn,E和WUE的种源差异有显著影响,并且Pn的种源差异由种源地气候、非气候因素共同导致;而RWC和SLA的种源差异主要由种源地非气候差异导致。【结论】黄柳叶功能性状在不同种源间、不同水分胁迫下均具有显著差异,但种源与水分胁迫对黄柳叶功能性状的影响程度不同。种源地气候可解释种源差异对黄柳叶功能性状解释的一部分,但种源地气候的影响在不同的叶功能性状之间存在很大差异。因此,黄柳叶功能性状的差异不仅反映不同种源对不同水分胁迫的生理生态响应,也体现不同种源由于生长的地理环境的差异所形成的特有生态适应性。

【Objecrive】This research investigated the effects of water stress,provenance and their interactions on leaf functional traits of Salix gordejevii,and explored the effect of climate on provenance differences. 【Method】One-year-old S. gordejevii seedlings were collected from six locations,and water stress experiments on the six provenances were conducted at four levels： mild, moderate and severe waterstress, and the control. A Li-Cor6400 photosynthesis measurement system was used to determine the photosynthetic indexes. The climate data of six locations were extracted from the World CLIM global high resolution（ 1 km × 1 km） climate database using Arc Gis9. 2,and mean annual precipitation（ MAP） and mean annual temperature（ MAT） were calculated using these climatic data. The response of leaf functional traits of six S. gordejevii provenances under different water stresses were analysed using analysis of variance（ ANOVA）. The effects of climate of origin,provenance and water stress on leaf function traits were examined using general linear model（ GLM）,and Pearson correlation was used to analyse the relationship between climate（ MAT,MAP）and leaf functional traits. 【Result 】1） net photosynthetic rate（ Pn）,transpiration rate（ E）,water use efficiency（ WUE） and relative water content（ RWC） of S. gordejevii were significantly affected by water stress. 2） Provenances had significant influence on all traits,but the strength differed among traits. For Pnand E,the effect of provenaces wasweaker than water stress; For WUE and RWC,provenance mainly influenced their responses to water stress; SLA was mainly affected by provenaces but not water stress. 3） Provenance climate had a significant impact on the provenance differences of Pn,E and WUE,and provenance differences of Pnwas led by climate and non-climatic factors of the seedling＇s origins. However,provenance differences of RWC and SLA were mainly caused by non-climatic factor.【Conclusion】There were significant differences for leaf functional traits of S. gordejevii among different provenances and under different water stress,but the influence strength of provenance and water stress on leaf functional traits was differented. Provenance climate could explain a part of the effect of provenance on leaf functional traits of S. gordejevii.However,there was remarkable difference in influence of provenance climate on different leaf functional traits. Therefore,the differences in leaf functional traits of S. gordejevii not only reflected the physiological and ecological responses of different provenances to different water stress,but also revealed to ecological adaptability of different provenances due to differences in geographical environment.