天仙子族(茄科)的花粉形态补充研究及其系统学意义(英文)

Supplemental study on the pollen morphology of the tribe Hyoscyameae(Solanaceae)and its systematic significance

关键词:  花粉形态  天仙子族  茄科  系统学意义

Key words:  pollen morphology  tribe Hyoscyameae  Solanaceae  systematic significance

摘要:

在扫描电镜下研究了茄科天仙子族7属及颠茄属、茄参属和枸杞属3属共10属23种植物的花粉形态学特征。结果表明:天仙子族的花粉粒形状为球形、近球形、扁球形和长球形; 萌发孔类型有无萌发孔、不规则的拟孔、3沟、4沟、3～4沟、散沟和3孔沟; 外壁纹饰为小刺状、瘤状、各式条纹状、条纹-穴状、条纹-网状、皱波状、细网状和网状。沟膜近光滑、具小颗粒、具小刺状突起或具瘤状突起。各属植物的花粉形态在萌发孔的有无、萌发孔的类型和外壁纹饰等方面有较大的差异,可以作为探讨属间分类和系统关系的重要依据。天仙子族植物花粉萌发孔的演化趋势为:无萌发孔→3、4沟→3孔沟。无萌发孔的山莨菪属是原始类群,三孔沟的马尿泡和天仙子等属是进化类群。还讨论了与前人研究结果不同之处和可能的原因。

Abstract:

Pollen grains of 23 species in seven genera of the tribe Hyoscyameae(Solanaceae)and three related genera(Atropa,Mandragora,Lycium)were investigated under SEM. The pollen grains are globose,subglobose,oblate or prolate in shape. Germination apertures were absent or present and are irregularly poroid,3-colpate,4-colpate,3-or 4-colpate,pantocolpate or 3-colporate. The exine ornamentation was spinulose,tuberculate,variously striate,striate-foveolate,striate-reticulate,rugose-sinuate,minutely reticulate or reticulate. The colpal membrane was nearly smooth but with granular,spinulose or tuberculate protuberances. The pollen grains show great variation between genera in the Hyoscyameae in the presence and type of a germination aperture and exine ornamentation. These may be important characters in revealing phylogenetic relationship in the tribe. The evolutionary trend in germination apertures ranges from absent or presence to 3-or 4-colpate then to 3-colporate. Anisodus,which lacks germination apertures,is considered to be primitive,while genera with 3-colporate pollen grains,such as Przewalskia and Hyoscyamus are believed to be advanced.