摘要
新疆野杏(Prunus armeniaca var.ansu)是世界杏的起源种之一,具有重要的经济和生态价值,近年来新疆野杏林出现了严重的衰退死亡现象,开展相关衰退机制研究对其资源保育和恢复具有重要意义。该研究以新疆伊犁地区相对健康(枯枝率≤30%)和严重衰退(枯枝率≥70%)的野杏树为研究对象,分析了碳失衡和木质部水力功能损伤在介导该树种衰退死亡过程中所起的作用。研究结果表明,严重衰退野杏树枝条水平的叶面积显著减少,但比叶质量、相对叶绿素含量和气孔导度在严重衰退和相对健康野杏树之间无显著差异。严重衰退野杏树的正午叶片水势、枝条水分传输效率和栓塞抵抗力均显著低于相对健康的野杏树,发生了明显的木质部水分传输障碍。严重衰退野杏树的非结构性碳水化合物(NSC)总含量低于相对健康的野杏树,但枝条木质部中可溶性糖与淀粉含量比例显著升高。水分传输效率的下降伴随着固碳能力和NSC库存的降低,碳失衡进一步导致树木对病虫害的防御能力降低,形成恶性循环最终导致树木衰退死亡。
Aims Wild apricot(Prunus armeniaca var.ansu)in Xinjiang of China,one of the origin species of apricot cultivars around the world,has important economical and ecological values,whereas natural apricot forests in Xinjiang have experienced serious decline and mortality in recent years.It is of great significance to carry out research on the underlying mechanisms for the conservation and recovery of wild apricots in Xinjiang.Methods In the present study,the xylem hydraulic properties and tissue non-structural carbohydrate(NSC)contents of relatively healthy(dead branches≤30%)and seriously declined(dead branches≥70%)wild apricot trees in Ili,Xinjiang were compared to analyze the potential role of hydraulic dysfunction and carbon imbalance in mediating the decline and mortality of this species.Important findings The results showed that the seriously declined apricot trees had significantly lower leaf area at the branch level,but there were no significant differences in leaf mass per area,relative chlorophyll content and stomatal conductance between the severely declined and relatively healthy trees.The midday leaf water potential,branch hydraulic efficiency and embolism resistance of seriously declined apricot trees were significantly lower than those of relatively healthy ones,indicating an evident xylem hydraulic impairment.The total NSC content of seriously declined trees was lower than that of relatively healthy trees,but the soluble sugar-to-starch content ratio in the stem xylem of seriously declined trees was significantly higher.Impaired hydraulic functioning was accompanied by decreased carbon assimilation capacity and reduced NSC reserve.On top of hydraulic dysfunction,carbon imbalance further contributed to the weakening of tree defense against scale insects,eventually leading to the decline and mortality of apricot trees due to the interplay between plant water relations and carbon economy.
作者
欧阳艺蕾
龚雪伟
段春旸
张驰
马尘扬
韩鹏
张元明
郝广友
OUYANG Yi-Lei;GONG Xue-Wei;DUAN Chun-Yang;ZHANG Chi;MA Chen-Yang;HAN Peng;ZHANG Yuan-Ming;HAO Guang-You(CAS Key Laboratory of Forest Ecology and silviculture,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China;Daqinggou Ecological Research Station,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Ürümqi 830011,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2024年第9期1192-1201,共10页
Chinese Journal of Plant Ecology
基金
中国科学院“西部之光”交叉团队项目(xbzg-zdsys-201910)
新疆维吾尔自治区“天池英才”计划项目
国家自然科学基金(31722013)
关键词
野杏
树木死亡
水力障碍
碳失衡
Prunus armeniaca var.ansu
tree mortality
hydraulic dysfunction
carbon imbalance