Abstract: The mature leaves of 59 Medicago ruthenica species from seven provinces of China were studied using paraffin method. The thickness of upper cuticle, low cuticle, leaves, palisade tissue and spongy tissue, diameter of vascular bundle, palisade tissue/spongy tissue ratio, palisade tissue structure tense ratio and sponge tissue structure loose ratio of leaves were measured by optical microscopy. Anova analysis showed that nine characters were significantly different among different regions (7.47%~24.49%). Correlation analysis showed that all indexes had significant correlation. Palisade tissue thickness, sponge tissue thickness, vascular bundle diameter and leaf thickness represented the most variable data. Clustering analysis showed that 59 materials were grouped into six groups and the genetic relationships among populations were related to geographic distribution. Annual precipitation and palisade tissue thickness, sponge tissue thickness and leaf thickness had positive correlation (P<0.05). Palisade tissue thickness, sponge tissue thickness and leaves thickness were a drought-resistance structure of Medicago ruthenica and related with drought-resistance of Medicago ruthenica.

Key words: Medicago ruthenica, Leaf anatomic traits, Environment factors, Correlation analysis

摘要： 为了探讨扁蓿豆(Medicago ruthenica)叶片组织结构与生境的关系,以来自我国7个省市(自治区)的扁蓿豆种质资源共59个居群的成熟叶片为试验材料,采用石蜡制片法,用光学显微技术测定叶片上表皮厚度、叶片下表皮厚度、叶片厚度、维管束直径、栅栏组织厚度、海绵组织厚度、栅海比、叶片栅栏组织结构紧密度和叶片海绵组织结构疏松度。方差分析表明:不同地区扁蓿豆解剖结构的9个特征表现出很大程度的差异性,变异系数变化范围为7.47%~24.49%;相关分析表明:各指标之间大多都存在一定的相关关系;主成分分析表明:栅栏组织厚度、海绵组织厚度、维管束直径及叶片厚度基本可以代表大部分叶片解剖结构特征的变异信息。聚类分析把59个居群分为6大类,表现出居群之间的亲缘关系与地理分布有一定的关联;生态因子分析表明:年降水量与栅栏组织厚度、海绵组织厚度及叶片厚度成显著正相关(P<0.05),推测栅栏组织厚度、海绵组织厚度和叶片厚度的大小与扁蓿豆种质资源的抗旱特性有关。

关键词: 扁蓿豆, 叶片解剖特征, 环境因子, 相关分析