Ovule and gametophyte development in Nicotiana glauca Graham (Solanaceae) |
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Authors: | Rosalba Villari Rachele Messina |
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Institution: | 1. Istituto ed Orto Botanico , Università di Messina , C. P. 58, 98166 Messina, S Agata, Italy;2. Dipartimento di Produzione vegetale e Tecnologie agrarie , Università di Udine , Via Fagagna, 208, loc. Rizzi, 33100, Udine, Italy |
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Abstract: | Abstract The development of ovule and megagametophyte is examined in Nicotiana glauca, using light microscopy. The ovules proved unitegmic, tenuinucellate and endothelial as in all the Solanaceae so far studied. The ovule primordia are of the three-zonate type. The integument, which is of dermal origin, is at first two-layered but later produces additional intermediate cells whose origin is not constant. The nucellus, whose initial curvature bears no relation to the origin of the integument, has, like other Solanaceae, a one or two-celled archesporium from which a single meiocyte develops. The gametophyte is confirmed to be bisporic in origin and its development follows the Allium type. Furthermore, the hypostase, which is rare in the family, is observed below the antipodal cells. |
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Keywords: | Embryology Nicotiana glauca ovule ontogeny Solanaceae |
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