Pollen morphology and detailed sexine of Passiflora subgenus Astrophea (Passifloraceae)

• DOI: 10.1007/s00606-015-1223-0
• Publication Date: 2015-05-19T12:51:15Z
• Authors: Ana C. Mezzonato-...; Michaele A. Milwa...; Cláudia Barbieri ...; Vania Gonçalves-E...
• Keywords: 0106 biological sciences; 01 natural sciences

From the palynological perspective, Passiflora subgen. Astrophea shows itself as a very interesting subgenus. The main aim of this study is to provide micro-characters that allow the recognition of taxa and the circumscription of the Passiflora subgen. Astrophea. The pollen was acetolyzed, measured, described and illustrated under light microscopy and non-acetolyzed pollen grains were analyzed in scanning electron microscopy. Quantitative data were subjected to multivariate analysis. The pollen grains are 6-colporate, 3-endoapertures clearly lalongate, unique for each pair of ectoaperture; tectate, partially tectate or semitectate exine, when present, muri may be only around the apertures or they may be remaining muri, continuous or discontinuous, simplicolumellate or duplicolumellate. The results defined four types of pollen, based on sexine, three of which were recognized by multivariate analysis. This study shows the importance of pollen morphology for the taxonomy of group, allowing a reassessment of the subgenus currently established and, hence, a better understanding of the recognized phylogenetic lineages.