Pollen Morphology of Some Species in the Family Solanaceae

The study investigates the significance of pollen morphology in the systematics of some species in the family Solanaceae. Pollen grains from anthers of Solanum gilo Linn., Solanum macrocarpon Linn., Capsicum frutescens Linn., Capsicum chinense Jacq., Physalis angulata Linn., Solanum pimpinellifolium (L.) Mill., Datura metel Linn., Solanum indicum Linn., Solanum torvum Sw., Nicotiana tabacum Linn. were collected and acetolysed and studied according to standard methods. The pollen grains of the species of the family Solanaceae studied looked similar with some differences. Acolpate pollen grains were observed in Capsicum frutescens, Datura metel, Nicotiana tabacum, and Solanum gilo while monocolpate was observed in Capsicum chinense, Datura metel, Solanum gilo, and Solanum indicum. Bicolpate pollen grains were observed in Capsicum chinense, Solanum pimpinellifolium, Physalis angulata, Solanum gilo, Solanum indicum and Solanum torvum. Tricolpate pollens were observed in all the species except in Datura metel which has only acolpate and monocolpate pollen types indicating that it is a primitive dicotyledon. Datura metel pollen grains also have a characteristic thick wall and the highest mean diameter, which delimits it from the other species. Nicotiana tabacum is the only species with tetracolpate pollens which is a mark of recent evolutionary descent in comparison to the other species studied. The pollen grains sizes fall into the classification groups minuta (pollen grain diameter 10–25µm) and media (pollen grain diameter 25–50µm).