Male (staminat) flower development, being separated in 8 phases, was investigated in Laurus nobilis (Lauraceae) through the usage of histological sections and scanning electron microscopy (SEM) analysis. Flower development starts when apical meristem differentiates, followed by the conversion of this structure to floral meristem. Initial development phases comprise incidents similar to the ones of the female flower. 4 tepals and 8-10 stamens primordia develop through floral meristem in turn. In early stages of the development, sexual dimorphism occurs when the carpel primordium arrests. Filaments carry 2 nectaries in stamens which arise in 3 whorls. Anther wall consists of epidermis, endothecium, 2 or 3 middle layers and a single-layered glandular tapetum. Anthers are bisporangiate. Meiotic division is regular in pollen mother cells, and pollen grains do not contain aperture. Beside the pollen scattered individually within the pollen sacs, groups which contain some pollen tied to each other are rarely observed, as well. Pollen grains seldom germinate within microsporangium. Anthers are opened with 2 valves which widen from the base through the top. Accumulation of polysaccharides, lipids and proteins were identified by histochemical methods in stamens. These organic substances are greater within and around the vascular bundle compared to other tissues.
The formation of non-hermaphroditic, i.e. male or female, flowers is a rare event in the plant kingdom. S. oleracea provides an ideal unisexual floral developmental system for studying the structural development of floral organs. These species forms non-hermaphroditic flowers; the pistil is fertile in the female flower, but the development of the stamens stops at an early phase and this organ atrophies and becomes functionless, while the male flowers form four fertile stamens, however there is not any trace of the pistil, it aborts at a much early stage. We searched for the presence of programmed cell death (PCD) in the abortive tissues during the ontogenetic development of these flowers. These results show curicial information on how the fertile sex organ in spinach differentiates and develops while arresting the development of the other aborted sex organ ; the presence of PCD occur in unisexual flower development in rhe very early stage and continue short time. We also found that stamen development in the female flower and pistil development in the male flower were subject to changes that did not result in large-scale structural changes. The PCD data obtained are the first study of spinach in the literature. This type of studies are shedding additional light on the sexual specialization hypothesis. Moreover, the ability to manipulate or control the flowering of the dioecious plant by simple means holds great potential, both from an economic aspect and to increase food production for an ever-growing human population
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.