RESUMO
In the present study, are extracted volatile concentrate from Ipomoea asarifolia Poir. and Ipomoea setifera (Desr.) Roem. & Schult. in five-month seasonal gradient. The flowers were subjected to simultaneous distillation - extraction (SDE). The chemical composition of the volatile concentrate was determined by gas chromatography (CG/MS) and (CG-FID). Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA) were performed with the chemical constituents. It was observed that the chemical composition of I. asarifolia varied more with seasonality in relation to the species I. setifera. Furthermore, there is a possibility that germacrene D and α-copaene, the main components of the variation volatile of I. asarifolia and with higher concentrations in the rainy months, have ecological importance, attracting specific pollinators for the rainy season. This is the first study to report the chemical composition of the volatile compounds of I. asarifolia and I. setifera along a seasonal gradient.
RESUMO
Ipomoea is a large pantropical genus globally distributed, which importance goes beyond the economic value as food resources or ornamental crops. This highly diverse genus has been the focus of a great number of studies, enriching the plant genomics knowledge, and challenging the plant evolution models. In the Carajás mountain range, located in Eastern Amazon, the savannah-like ferruginous ecosystem known as canga harbors highly specialized plant and animal populations, and Ipomoea is substantially representative in such restrictive habitat. Thus, to provide genetic data and insights into whole plastome phylogenetic relationships among key Ipomoea species from Eastern Amazon with little to none previously available data, we present the complete plastome sequences of twelve lineages of the genus, including the canga microendemic I. cavalcantei, the closely related I. marabaensis, and their putative hybrids. The twelve plastomes presented similar gene content as most publicly available Ipomoea plastomes, although the putative hybrids were correctly placed as closely related to the two parental species. The cavalcantei-marabaensis group was consistently grouped between phylogenetic methods. The closer relationship of the I. carnea plastome with the cavalcantei-marabaensis group, as well as the branch formed by I. quamoclit, I. asarifolia and I. maurandioides, were probably a consequence of insufficient taxonomic representativity, instead of true genetic closeness, reinforcing the importance of new plastome assemblies to resolve inconsistencies and boost statistical confidence, especially the case for South American clades of Ipomoea. The search for k-mers presenting high dispersion among the frequency distributions pointed to highly variable coding and intergenic regions, which may potentially contribute to the genetic diversity observed at species level. Our results contribute to the resolution of uncertain clades within Ipomoea and future phylogenomic studies, bringing unprecedented results to Ipomoea species with restricted distribution, such as I. cavalcantei.