【作者】 胡金蓉；

【导师】 周守标；

【作者基本信息】 安徽师范大学 ， 植物学， 2007， 硕士

【摘要】 山罗花属植物为一年生半寄生草本植物,产北半球,全世界约20种。该属植物因叶和苞片等形态变异较大,在分类处理上存在较大的差异。有关山罗花属植物的研究,国外主要在生化、生理及生态等方面做过一些工作;国内除植物志对该属国产种类进行分类记载外,仅对山罗花进行简单的生药鉴定研究。因此,山罗花属植物缺乏系统研究资料。本研究以山罗花属植物13种4变种为研究材料,通过运用光镜、扫描电镜、统计分析和野外调查等方法,从微形态特征等方面对山罗花属植物进行了详细的研究,为探讨山罗花属植物的系统演化关系、对环境的适应机制以及半寄生特征机理提供有效的实验证据。研究结果如下:1.在光学显微镜和扫描电镜下,观察了山罗花属13种及4变种植物的叶表皮特征。结果表明:该属植物叶表皮细胞形状为不规则形;垂周壁为浅波状、波状、深波状和重波状;气孔器为无规则型,通常仅分布在下表皮,只有Melampyrum pretense, Melampyrum cristatum和Melampyrum arvense三种植物的上表皮上有无规则型的气孔器分布。该属植物的上下表皮有非腺毛和腺毛的分布,其中下表皮腺毛多于上表皮;扫描电镜下非腺毛具瘤状突起的纹饰;气孔器外拱盖内缘为近光滑、浅波状或波状;角质膜具条纹。细胞垂周壁式样和气孔器特征等微形态性状在种间存在一定的差异,为探讨该属植物的系统演化关系提供有价值的性状依据。2.对安徽产山罗花和天柱山罗花2种4居群的15项形态特征进行了数值分析表明,形态性状在2种4居群间均存在一定程度的变异,居群间变异系数的平均值从小到大排列为:天柱山居群(天柱山罗花)、天柱山居群(山罗花)、黄山居群(山罗花)、鹞落坪居群(山罗花);天柱山罗花与山罗花种间所有形态性状的差异均达到极显著水平,山罗花的3居群间仅有部分形态性状达到极显著水平;以15项形态特征为基础的Q-聚类分析可以把天柱山罗花和山罗花明显聚为两类,R-聚类分析发现了强正相关关系、弱正相关关系、弱负相关关系的性状。因为天柱山罗花与山罗花15项形态性状差异显著,进一步证明新种天柱山罗花成立;山罗花居群的性状差异与地理分布距离没有明显相关性,这种变异可能与生境的差异有关。3.对山罗花属13种植物的的叶和苞叶等形态特征进行了数值分析。结果表明:山罗花属植物存在广泛的变异性;形态性状在13种植物间存在显著的差异;以形态特征为基础的Q-聚类分析可以将所研究的13种植物分为显著不同的3类。4.通过对安徽产山罗花属2种植物的根、吸器、茎和叶的解剖结构研究表明,山罗花和天柱山罗花根部均表现为木质部发达,韧皮部退化;吸器由大量薄壁细胞和长形螺纹导管组成;茎节间中央被宽阔的髓所占据,薄壁组织发达;叶片内叶肉组织具有发达的胞间隙等,但两者在栅栏组织与海绵组织厚度比、中脉在远轴面的隆起程度和导管的数目等方面有明显的差异。更多还原

【Abstract】 Melampyrum L. is a genus of annual hemiparasitic herbaceous plants, consisting of about 20 species in the Northern hemisphere. There is a great deal of variation in certain characters, especially in leaf and bract morphology, and many differences exist in the disposal of taxon. So far, some work carried on by oversea scientists were focused on biochemistry physiology and ecology of Melampyrum L., and in China, there were only some researches about pharacognostical identification besides some taxon recordations from Chinese floras. However, there were few systematic studies on Melampyrum L. The micromorphological characters of 13 species and 4 varieties of Melampyrum L. over the world were studied detailedly by LM, SEM, statistic analysis and field investigation in this paper. It might provide some valuable experimental datas for the systematic evolution relationship of Melampyrum L., the adaptation mechanism to the ecological environment, and the characters and mechanism of semiparasite. The results were as follows:Firstly, the leaf epidermis of 22 samples representing 13 species and 4 varieties were investigated under both light microscope (LM) and scanning electron microscope (SEM). It was shown that the leaf epidermal cells were usually irregular in shape. The patterns of anticlinal walls were sinuolate, sinuous, sinuate or double-sinuate. The stomatal apparatus which mostly distributed in lower epidermis were often anomocytic. Both nonglandular hairs and glandular hairs were on the epidemis, but there were more glandular hairs on the abaxial epidermis than those on the adaxial epidermis, the nonglandular hairs had neoplasitic process under SEM. The inner margin of the outer stomatal rim was nearly smooth, sinuolate or sinuous, and the cuticular membrane was striate. Characters of the leaf epidermis in Melampyrum L., such as patterns of anticlinal walls, shapes of guard cells and inner margin of the outer stomatal rim, appeared to be constant with species and thus could be used for distinguishing some species. The results also suggested that the patterns of anticlinal walls and the characters of stomatal apparatus might provide some valuable evidences for systematic relationship and evolutionary trend.Secondly, 15 morphological characters of 2 species and four populations in M. roseum and M aphraditis were studied by numerical analysis. The results showed that: (1)The morphological characters showed certain var..iation within 2 species and 4 populations, the order according to the variation level of them was Tianzhushan population (M. aphraditis)<Tianzhushan population (M. roseum)<Huangshan population (M. roseum)<Yaoluoping population (M. roseum). There existed remarkably significant morphological differentiations between M. aphraditis and M. roseum, some differentiations among the three populations of M. roseum also reached a remarkably signicant level. In Q-analysis, M.aphraditis and M. roseum could be divided into two groups; In R-analysis, the characters of great positive correlation, infirm positive correlation and infirm negative correlation had been found. Because of the significant differences between M. roseum and M. aphraditis, the results supported the new species of M.aphraditis came into existence. The morphological variations of M. roseum might be influenced by environment factors, while its correlations with the geographical distances was not significant.Thirdly, Morphological characters of leaves and bracts of Melampyrum L. were studied by numerical analysis. The results showed that: There existed remarkably significant morphological variation in Melampyrum L.. Great differences also existed among the thirteen species of Melampyrum L.. Clustering analyses based on morphological characters revealed that thirteen species of Melampyrum L could be divided into three groups.Lastly, the root, haustrum, stem and leaf structures of Melampyrum L. in Anhui province were studied. It was shown that the xylem was well developed, while the phloem was comparatively degenerated; the haustrum was composed of parenchyma and spiral vessels; the center of the stem abounded with square-built marrow with developed parenchyma; there was much developed intercellular space in the mesophyll; but the results showed that there were many significant anatomical differences among two species, such as are the ration of palisade tissue to apongy tissue, the degree of the protuberance in the midrib and the numbers of the vessels.更多还原