干旱和遮荫对马尾松幼苗瞬时水分利用效率及δ^(13)C的影响  

Effects of drought and shading on instantaneous water use efficiency andδ^(13)C of Pinus massoniana seedlings

作　　者：邓秀秀 施征[2] 曾立雄[2] 雷蕾 裴顺祥[1] 吴莎 肖文发[2] DENG Xiuxiu;SHI Zheng;ZENG Lixiong;LEI Lei*;PEI Shunxiang;WU Sha;XIAO Wenfa(Experimental Center of Forestry in North China,Chinese Academy of Forestry,Beijing Jiulong Mountain National Long-term Scientific Research Base of Warm Temperate Forests,Beijing 102300,China;Ecology and Nature Conservation Institute,Chinese Academy of Forestry,Key Laboratory of Forest Ecology and Environment,State Forestry and Grassland Administration,Beijing 100091,China)

机构地区：[1]中国林业科学研究院华北林业实验中心,北京九龙山暖温带森林国家长期科研基地,北京102300 [2]中国林业科学研究院森林生态环境与自然保护研究所,国家林业和草原局森林生态环境重点实验室,北京100091

出　　处：《生态学杂志》2024年第1期140-145,共6页Chinese Journal of Ecology

基　　金：国家重点研发计划项目(2016YFD0600201);中央级公益性科研院所基本科研业务费专项资金重点项目(CAFYBB2021QD002)资助。

摘　　要：水分利用是植物光合固碳的关键过程,其效率反映植物对胁迫环境的适应能力,δ^(13)C作为反映植物长期水分利用效率的关键指标,对于揭示植物与环境长期作用的关系具有重要意义。本研究以马尾松幼苗为对象,通过土壤水分和光照条件控制,设置干旱(土壤水分为30%饱和含水量)、遮荫(光照强度为全光照的30%)及干旱+遮荫(土壤水分为30%饱和含水量和光照强度为全光照的30%)3种胁迫方式和对照(CK,土壤水分为70%饱和含水量和全光照),研究干旱和遮荫对马尾松瞬时水分利用效率和δ^(13)C的影响。结果表明:干旱和干旱+遮荫处理分别使马尾松当年生叶的瞬时水分利用效率显著增加了67.96%和60.78%,遮荫对瞬时水分利用效率的影响不显著;当年生叶的δ^(13)C在干旱处理下显著增加了14.35%,但在遮荫和干旱+遮荫处理下未发生明显改变;各处理对1年生叶δ^(13)C的影响均不显著;表明瞬时和长期水分利用效率的变化不同步,且马尾松的水分利用效率对干旱的响应较早;在各处理下,各库器官中的δ^(13)C均大于源叶,茎干和根中的δ^(13)C与源叶δ^(13)C的相关系数较大,且与1年生叶呈极显著正相关,各库器官的δ^(13)C主要受源叶δ^(13)C供应的影响。表明环境变化导致水分利用效率的变化将引起各库器官δ^(13)C发生改变。研究结果可为揭示马尾松幼苗对气候变化的响应机制提供参考。Water use is a key process of photosynthetic carbon sequestration in plants.δ^(13)C is a key indicator for long-term water use efficiency(WUE),reflecting the adaptive ability of plants to stressful environments.It is thus of great significance to reveal the long-term relationship between plants and environment.In this study,we examined the effects of drought and shading on instantaneous WUE andδ^(13)C in Pinus massoniana seedlings under four treatments,including drought(30%saturated water content of soil moisture),shading(30%of full light intensity),drought+shading(30%saturated water content of soil moisture and 30%of full light intensity),and CK(70%saturated water content of soil moisture and full light intensity).The instantaneous WUE in the current-year needles significantly increased by 67.96%and 60.78%under drought and combined stress,respectively.δ^(13)C significantly increased by 14.35%under drought,but did not significantly change under shading and combined stress.However,theδ^(13)C values did not significantly change in the 1-year-old needles under three treatments.This indicated that the changes of instantaneous and long-term water use efficiency were not synchronized in P.massoniana,with WUE responded earlier to drought.Theδ^(13)C value in sink organs was higher than that in the source needles under all treatments.Moreover,δ^(13)C in stems and roots had significant correlation with that in needles,which was significantly positively correlated with that in 1-year-old needles.Theδ13 C value in sink organs was also mainly influenced by the supply of source needles.These results implied that the changes in WUE caused by changing environments could further affectδ^(13)C in each sink organ,which would provide a reference for the understanding the mechanism underlying the responses of P.massoniana seedlings to climate change.

关 键 词：干旱 遮荫 水分利用效率 δ^(13)C 马尾松幼苗 

分 类 号：S791.248[农业科学—林木遗传育种]