内蒙古扁蓿豆叶片解剖性状与抗旱性的研究

以来自内蒙古的野生扁蓿豆种质资源32个居群成熟叶片为试验材料,采用石蜡制片法,应用光学显微技术测定了叶片上表皮厚度、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等与抗旱相关的解剖结构特征参数,并进行统计分析和抗旱性综合评价。结果表明,9个指标均表现差异极显著;叶片上表皮厚度、叶片下表皮厚度、叶片厚度、栅栏组织厚度和海绵组织厚度之间呈极显著相关和显著相关关系;第3个主成分的特征值为1.621,累计贡献率达86.67%,已超过85%,前3个主因子基本上能概括9个指标的主要信息;采用UPGMA法将32个居群分成五大类。隶属函数法综合评价抗旱能力显示16和27号居群的抗旱性最强,22号居群抗旱性最差。

A study on leaf anatomic traits and drought resistance of Medicago rutenica in Inner Mongolia

The aged leaves of wild Medicago rutenica in 32 populations were observed in Inner Mongolia using paraffin wax embedded sections to analyse and evaluate drought resistance.Optical microscopy was used to measure the anatomical structure of drought-related parameters including the thicknesses of the upper and lower cuticles,leaf,palisade and spongy tissues,the diameter of the vascular bundles,the ratio of palisade to spongy tissue,the tightness of leaf palisade tissue structure and the looseness of leaf sponge tissue structure.Nine indexes differed significantly.There were significant correlations between the thicknesses of the upper and lower cuticles,leaf,palisade and spongy tissues and drought resistance.The eigen value of the third principle component was 1.621 and accumulative rate was 86.67%.The first three principle factors generalized the main information of 9 characters.The 32 populations were divided into 5 groups by the UPGMA method.The membership function to evaluate drought resistance showed that No.16 and 27 had strong drought-resistant while No.22 was weak.