Anatomy and ultrastructure of the floral nectary in Peganum harmala L. (Nitrariaceae) |
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Authors: | MASUMEH ABEDINI ALI MOVAFEGHI MAHBUBEH ALIASGHARPOUR MOHAMMAD REZA DADPOUR |
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Institution: | 1. Department of Biology, Payame Noor University, Tehran, Iran;2. Department of Plant Biology, Faculty of Natural Sciences, University of Tabriz;3. Department of Horticultural Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran |
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Abstract: | Anatomy and ultrastructure of the floral nectary of Peganum harmala L. were studied using light and transmission electron microscopy. The floral nectary was visible as a glabrous, regularly five‐lobed circular disc encircling the base of the ovary. Anatomically, it comprised a single layered epidermis and 15–20 layers of small, subepidermal secretory cells overlying several layers of large, ground parenchyma cells. The floral nectary was supplied by phloem and both sieve tubes and companion cells were found adjacent to the ground parenchyma. Based on our ultrastructural observations, plastids of secretory cells during the early stages of development were rich in starch grains and/or osmiophilic plastoglobuli, but these disappeared as nectar secretion progressed. The nectar appeared to exude through the modified stomata along symplastic and apoplastic routes. The abundant plastids and mitochondria suggest an eccrine mechanism of nectar secretion in P. harmala. |
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Keywords: | eccrine secretion floral nectary nectar secretion Nitrariaceae Peganum harmala |
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