Objective:The objective of this study was to provide palynology evidence for the phyletic classification of the genus Corylus and reveal the relationship between the morphological characteristics of pollen and phyletic classification of Corylus. Method:14 Corylus samples from different species and cultivars were used in the experiment. The plant materials are cultured and the pollens are collected with standard methods. All samples were fixed by FAA stationary liquid and desiccated by CO2 ridge boundary drying. The indices such as the shape and size of the pollen, aperture spacing, extine ornamentation, thorn size and density were measured using scanning electron microscopy. The cluster analysis was performed based on the observational data. Results:The pollen of Corylus was characteristic of single grain pollen with three apertures distributed in equatorial plane, and defined to be explained by N3 P4 C4 model. The pollen was oblate spheroidal in shape, the polar view was triangle and the equatorial view was elliptic. The extine ornamentation of pollen was rugulate and echinate. Different samples were differed in pollen size, extine ornamentation, thorn size and density. Based on the pollen morphology characteristics, the cluster analysis indicated that 14 pollen samples were classified into three groups. The first group included C. chinensis Franch. , C. fargesii Schneid. , C. kweichowensis Hu, Ping' ou hybrid hazelnut'Dawei' ,'Liaozhen No. 3', European hazelnut 'Casina' and 'Ennis', which showed middle?sized pollen and inconspicuous rugulate. The second group included the three varieties of C. heterophylla Fisch. ('JMS ' , 'HLP ' , 'WC ' ) and C. mandshurica Maxim. , which showed inconspicuous rugulate and small dense echinate. The third group included C. ferox Wall. Var. thibetica ( Batal. ) Franch. , European hazelnut 'Maria' and Ping ' ou hybrid hazelnut 'Liao zhen No. 7 ' , which showed conspicuous rugulate and sparse echinate. Conclusion:There were great differences in palynology indices in the genus Corylus, such as the pollen size, exine ornamentation, size and density of thorn, which could be used in the classification and identification in Corylus. The sampling and experimental method in this study could be used as reference in the related researches.%目的:为榛属植物的系统分类学提供孢粉学证据,明确榛属植物花粉形态特征及其与品种分类、系统进化的关系.方法:采用一致的方法培育植物材料并收集花粉,以14份不同种(品种)的榛属植物花粉为材料,使用FAA固定液固定,二氧化碳临界点干燥法处理花粉,在扫描电子显微镜下观察花粉的形状、大小、萌发孔距、萌发孔径比和表面纹理等指标,并进行聚类分析.结果:榛属植物的花粉为单粒花粉,多为3萌发孔,萌发孔分布在赤道面上,属于N3 P4 C4类型;花粉形状为近扁球形,极面观为三角形,赤道面观为椭圆形,花粉外壁纹饰为皱波状和刺状,不同种(品种)的花粉在大小、皱波明显度、刺的大小和密度上存在差异;对上述指标进行聚类分析,将14份样品聚为3类.第1类:华榛、绒苞榛、川榛、'辽榛3号'、'达维'、'Casina'和'Ennis',属于中等大小花粉,皱波不明显;第2类:平榛'JMS'、'HLP'、'WC'和毛榛,花粉表面皱波不明显,刺较小且致密;第3类:藏刺榛、'Maria'和'辽榛7号',花粉表面皱波明显,刺的分布密度较疏.结论:榛属植物的花粉在大小、外壁皱波纹饰、刺的大小和密度方面差异较大,可为榛属植物的种属分类和品种鉴定提供孢粉学依据;本研究的取样和实验方法也可为其他相关研究提供参考.
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