基于木质部栓塞特性的扁桃砧木抗旱机理研究

The almond （Amygdalus communis L. ）, is one of the four most famous nuts in the world. The exploration and utilization of Almond rootstock resources in China has become an important task for the drought resistant breeding of Almond. Many studies have shown that drought resistance of woody plants has close relations with its xylem embolism resistance, or form a metabolically active embolism repair mechanism to cope with water-stress induced embolism. .In this research, 14 Almond native variety resources from Central-Asia type will be selected as research objects. Through pot experiment, the response of different Almond varieties to water stress was studied from morphological anatomy, physiological and biochemical aspects and several Almond rootstock resources with highly drought resistant and drought sensitive will be screened out.Taking the xylem embolism features as a key point, analyze the differences of xylem embolism resistance and embolism repair ability of several Almond rootstocks with different degree of drought resistance under water stress conditions. The relationship between nonstructural carbohydrate (NSC) content, leaf water channel protein (AQPs) gene expression and ability of embolism repair will be studied. The correlations and interaction mechanism between the xylem anatomy, resistant of the embolism, embolism repairmen and the drought resistance of the rootstocks will be discussed. The drought resistant mechanism of Almond rootstocks will be trying to explain from the xylem hydraulics aspects. This study is of great value for the future mining of drought resistant genes and selection of drought resistant rootstock by molecular assisted breeding。

扁桃（Amygdalus communis L. ）是世界四大名坚果之一。发掘和利用我国丰富的扁桃砧木资源，已成为扁桃抗旱育种工作的一项重要任务。众多研究表明，木本植物的抗旱性与木质部栓塞抗性能力或活跃的代谢修复栓塞能力密切相关。本研究以中亚类群14种扁桃品种资源为试材，通过人工水分胁迫实验，从形态解剖、生理生化角度系统研究扁桃不同品种资源对干旱胁迫的响应，筛选出抗旱性差异显著的几种扁桃砧木资源；以木质部栓塞特性为切入点，解析抗旱性不同扁桃砧木在水分胁迫下其木质部栓塞抗性和栓塞修复能力的差异，探索非结构性碳水化合物（NSC）含量、叶片水通道蛋白（AQPs）基因表达量与栓塞修复之间的关系，解读木质部解剖结构、栓塞抗性、栓塞修复和砧木抗旱性程度之间的内在关联及相互影响机制，揭示扁桃抗旱砧木的水力耐旱机理。本研究对今后通过分子辅助育种挖掘抗旱基因、选育抗旱砧木有重要的应用价值。

扁桃（Amygdalus communis L. ）是世界四大名坚果之一。发掘和利用我国丰富的扁桃种质资源，为桃属植物抗旱育种工作的一项重要任务。众多研究表明，木本植物的抗旱性与木质部栓塞抗性能力或活跃的代谢修复栓塞能力密切相关。本研究以14份本地扁桃砧木资源的实生苗为试材, ① 通过盆栽干旱胁迫实验,系统研究扁桃不同砧木资源实生苗在干旱胁迫下叶片显微及亚显微结构、生理生化指标、地上地下生物量以及根系形态结构的变化，并对砧木资源进行抗旱性综合评价，筛选出抗旱能力较强的扁桃砧木资源3份，即大巴旦、石头扁桃和苦巴旦；②以不同种质资源为砧，以纸皮扁桃为接穗的扁桃6个不同嫁接组合进行干旱胁迫处理，从不同生理角度研究不同砧木对同一接穗品种的抗旱效应，结果显示干旱胁迫下喀什桃/纸皮组合的光合和生理生化特性比扁桃本砧组合均受到较明显抑制；大巴旦/纸皮组合地下总生物量出现小幅度增加之外，其它砧穗组合的均出现下降，喀什桃/纸皮组合根系总生物量相比其他砧穗组合最低；③ 以木质部栓塞特性为切入点，分别分析抗旱性差异较大的5个砧木资源的栓塞抗性、栓塞修复和木质部解剖结构差异，结果显示，扁桃砧木资源茎木质部栓塞脆弱性(P50)平均值由小到大依次为大巴旦、甜仁桃扁桃、苦扁桃、苦仁桃扁桃、普通桃，普通桃的抗栓塞能力最弱，大巴旦的抗栓塞能力最强；木质部栓塞修复能力大小依次为：普通桃>苦仁桃扁桃>甜仁桃扁桃>苦扁桃>大巴旦，抗栓塞能力较弱的扁桃砧木资源容易发生栓塞，但其栓塞修复能力较高；④扁桃砧木资源茎抗栓塞能力与栓塞修复能力之间具有较好的负相关关系,与木材密度之间有显著正相关关系。然而茎木质部栓塞修复能力与木质部导管直径、纹孔膜上微孔直径间有较好的正相关关系,与木材密度间有较好的负相关关系,说明大巴旦的抗栓塞能力在5种砧木资源里最强，但它的栓塞修复能力最弱。本研究对今后通过分子辅助育种挖掘抗旱基因、选育桃属植物抗旱砧木有重要的应用价值。项目期，共计发表或已接收文章6篇，其中SCI文章1篇，CSCD文章5篇；培养研究生1名。