Of the species investigated, most displayed similar anatomical organization, their trichomal elaiophores occurring on the labellar callus. They, thus, differ from many other members of the Oncidiinae, where epithelial elaiophores are found either on the callus, or on the lateral lobes of the labellum. However, ultrastructurally, all elaiophores, whether those of representatives of the Ornithocephalus clade, or those of other oil-secreting Oncidiinae, possessed a similar complement of organelles, regardless of whether the elaiophores were trichomal or epithelial. In view of the latter, and the similar chemical composition of oils derived from all Oncidiinae investigated to date, it is probable that position and type of elaiophore, and possibly the structure of the overlying cuticle, play an important role in pollinator selection in these oil-secreting orchids.
The shining appearance of the flowers of Oncidium cheirophorum and Ornithocephalus kruegeri results from the presence of lipids on the flower surface. The lipids are produced by elaiophores - secretory structures situated symmetrically at the base of the labellum or upon the callus. In O. cheirophorum, the elaiophores are epithelial type. They consist of one layer of cuboidal secretory cells and subsecretory parenchyma. The thick cuticle covering the outer, tangential wall of epithelial cells becomes distended and wrinkled as secreted oil accumulates beneath its surface. Oil secretion begins at the bud stage and lasts till the end of anthesis, that is 22 days, on average. Pollination does not influence oil production. In O. kruegeri, trichomatous elaiophores are situated on the central part of the callus. Unicellular trichomes project from the epidermis cells. Their outer walls are covered by a thin cuticle. In the dense cytoplasm of the trichomes, small plastids with few starch grains occur, whereas subsecretory parenchyma cells contain amyloplasts with large starch grains and raphides. The oil is already produced at the bud stage, about one week before flower opening, and lasts till the end of anthesis
Plasmogenes are largely located in mitochondria or plastids and they can influence the inheritance of many plant characteristics. This phenomenon is called cytoplasmic inheritance and can be detected on the basis of the expression of a trait in progeny F1 obtained from single and reciprocal crosses. The aim of this study was to examine the cytoplasmic inheritance of in vitro productivity of morphogenesis in three genotypes of Fragaria x ananassa Duch., i.e. the cultivars 'Dukat', 'Teresa' and the breeding clone no. 590. Single and reciprocal crosses were done according to Griffi ng's method 3. The value of general combining ability (GCA) indicated cv. 'Teresa' as the best maternal component for crossing and 'Dukat' as the worst. The negative reciprocal cross effects (rij) revealed the cytoplasmic inheritance for cv. 'Dukat' as maternal form and positive rij for the breeding clone no. 590 indicated the nuclear inheritance of morphogenetic ability. Cv. 'Teresa', as maternal component, showed nuclear inheritance of that trait in crossing with cv. 'Dukat' and with 590 cytoplasmic inheritance. The productivity of morphogenesis in strawberry depended on the parental combination and the direction of crossing
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.