扁桃不同砧木资源根系解剖结构对干旱胁迫的响应

Response of root anatomical structure of different rootstock resources of almond to drought stress

【目的】研究扁桃6个不同砧木资源当年生实生苗根系解剖结构特征对周期为60 d的中度土壤干旱胁迫的响应,为扁桃砧木抗旱机理的研究提供形态解剖学的依据。【方法】采用水分控制盆栽试验,运用光学显微镜观察,获取根组织解剖结构和木质部解剖结构相关12项指标,分析生物学特性。【结果】大巴旦和石头扁桃的根木栓层、木栓层数、木质部占比以及维管束占比等指标值比其它砧木资源的高(P<0.05),且干旱胁迫之后,其木栓层、木栓层数均增加(P>0.05);主成分分析筛选出主根(D≥5 mm)木栓层厚度、侧根(2<D<4 mm)木栓层厚度、主根木质部占比以及侧根导管直径等4项抗旱性相关指标;从根系解剖结构角度对扁桃不同砧木资源苗期进行抗旱性排序为大巴旦>石头扁桃>苦扁桃>桃巴旦2号>桃巴旦1号>桃。【结论】扁桃本砧资源根系的木质化程度较高,与其他砧木资源相比对干旱胁迫环境具有更好的适应能力。

【Objective】To study the response of root anatomical structure characteristics of current year seedlings of 6 different rootstock resources of almond to moderate soil drought stress with a cycle of 60 days through water control pot experiment,so as to provide morphological and anatomical basis for the study of drought resistance mechanism of almond rootstock.【Methods】12 indexes related to the anatomical structure of root tissue and xylem were obtained by optical microscope,and biological statistical analysis was carried out.【Results】The index values of root cork layer,cork layer number,xylem proportion and vascular bundle proportion of Dabadan and Shitou almond were higher than those of other rootstock resources(P<0.05),and the cork layer and cork layer number increased after drought stress(P>0.05);Four structural indexes related to drought resistance were selected by principal component analysis,such as the thickness of cork layer of coarse root(D≥5 mm),the thickness of cork layer of fine root(2<D<4 mm),the proportion of xylem of coarse root and the diameter of lateral root canal;Through the method of membership function analysis,the drought resistance of almond rootstock resources at seedling stage were ranked from the perspective of root anatomical structure.The results were as follows:Babadan>Shitou almond>Bitter almond>Taobadan 2>Taobadan 1>peach.【Conclusion】Almond rootstock resources have a higher degree of root lignification,and have better adaptability to drought stress environment than other rootstock resources.