北美洲当归属(伞形科)植物花粉形态特征研究  

Palynological Research on the Angelica Species(Apiaceae)from North America

作　　者：杨明乐 廖晨阳[1] YANG Mingle;LIAO Chenyang(College of Architecture and Environment,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学建筑与环境学院,成都610065

出　　处：《西北植物学报》2023年第7期1236-1250,共15页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金项目(31400195,31700176);四川大学基层教学组织特色品牌项目(2021JCJX14)。

摘　　要：花粉形态特征可为伞形科当归属的分类鉴定与亲缘关系研究提供重要依据;北美洲当归属植物是该属的重要分支分群,但其花粉学研究却鲜受关注。为进一步充实孢粉学研究资料,使用光学显微镜与扫描电子显微镜对北美洲当归属26种44个居群的花粉形态和外壁纹饰进行观察,并用SketchUp软件对花粉极轴及赤道轴长度、体积指数和纹饰密度等特征进行测量分析和定量定义。研究结果显示:(1)供试花粉包含椭圆形、近长方形、超长方形与超长方形(赤道缢缩)4种形状;(2)花粉极轴长度为21.1~32.0μm,赤道轴长度为10.6~17.1μm,极轴与赤道轴的比值为1.5~2.8,体积指数为15.8~23.3;(3)花粉赤道区外壁纹饰分为3类,包括长条状脑纹、短棒状脑纹以及片状脑纹,排列或密集或稀疏,其中3个物种的纹饰在极区变平滑;(4)根据上述形态特征,可将供试花粉划分为4级3大类15小类。研究结果表明,总体上北美洲当归属植物花粉的形态特征的多态性低于东亚当归属植物;花粉形状与赤道区外壁纹饰具有较高的种内一致性,花粉中部是否凸出以及纹饰类型、密集程度、附属物等特征则存在一定程度的种内差异。该研究进一步充实了当归属的孢粉学研究资料,花粉形态特征能够为该类群的分类鉴定与亲缘关系研究提供重要依据,可作为形态分类学和分子分类学的有力补充。The morphological characteristics of pollens provide important evidence for the classification and phylogenetic relationship research of Angelica(Apiaceae).The North American Angelica species are believed as an important group of the Angelica genus,but its pollen morphologies has rarely received attentions up to now.Aim to enrich further data of the palynological research,the authors observed the pollen morphology and exine ornamentation of 26 species and 44 populations of the Angelica genus in North America using optical microscopy and scanning electron microscopy.The SketchUp software was used to measure and define features such as polar axis and equatorial axis length,volume index,and ornamentation density of the pollen.The results show that:(1)There are four types of pollen shapes as subrectangular,ellipsoidal,hyperretangularb and hyperretangular(equatorial constriction).(2)Their polar axis length is 21.1-32.0μm,the equatorial axis length is 10.6-17.1μm,the ratio of polar axis to equatorial axis is 1.5-2.8,and the volume index is 15.8-23.3.(3)The ornamentations on exine walls of pollen equatorial regions includes three types,such as brevistriate baculite cerebroid,lone striate cerebroid,and flaky-like cerebroid,sparsely or densely arranged,and the polar ornamentations of three species turn to smooth.(4)According to the above characteristics of these pollens,a classification system comprising 4-levels,3-classes and 15-subclasses are suggested herein.In general,the polymorphism of the pollen characteristics of North America Angelica species is lower than that in East Asia;the pollen shape and the types of the equatorial ornamentations of the exine walls are relatively consistent in each species,yet the central pollen protruding,ornamentation types and density,and appendages exhibit a certain intra-specific difference.The study supplies further data of the palynologies of Angelica,and the pollen characteristics will provide significant reference to the classification,identification and the relationships of the

关 键 词：孢粉学 当归属 北美洲 扫描电镜 外壁纹饰 

分 类 号：Q944[生物学—植物学]