Pollen morphology of the southern African tribe Teedieae, an early-branching lineage of crown Scrophulariaceae

• Autores: Sergei L. Mosyakin, Zoya M. Tsymbalyuk
• Localización: Willdenowia: Annals of the Botanic Garden and Botanical Museum Berlin-Dahlem, ISSN 0511-9618, ISSN-e 1868-6397, Vol. 45, Nº. 1, 2015, págs. 65-75
• Idioma: inglés
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• Resumen

  • The pollen morphology of seven species representing four genera of the tribe Teedieae (Scrophulariaceae) is described and illustrated using light microscopy (LM) and scanning electron microscopy (SEM). Two major pollen types, 3-colporate and 4-colporate, are recognized by aperture types. Within these pollen types, subtypes are distinguished based on exine sculpture, colpi, colpus membrane, and endoaperture characters. Within type I (3-colporate), three subtypes are recognized: Ia — sculpture psilate, rarely with microperforations; Ib — sculpture microperforate and microreticulate; and Ic — sculpture macroreticulate. Type II (4-colporate) is represented by only one subtype IIa — sculpture psilate, rough, and foveolate. The revealed characteristics of pollen grains are taxonomically significant at the generic and specific levels. Our palynomorphological data are consistent with the results of molecular phylogenetic studies. Pollen grains in Teedieae are typically characterized by the colporate aperture type (probably ancestral in Scrophulariaceae) and rather primitive characters of surface and sculpture of colpi membranes. Similar palynomorphological patterns in Teedieae and Buddlejeae can be viewed as ancestral for pollen characters observed in more advanced clades of Scrophulariaceae.