RESUMEN
Chrysolaena flexuosa (Sims.) H. Rob. is a South American species in the tribe Vernonieae, with potential ornamental value: it has attractive inflorescences, is suitable for pot cultivation, and its cypselae are useful for dried flower arrangements. Apart from studies on the growth dynamics of this species under cultivation, chromosome number, DNA content, ploidy level, size, pollen viability, and the characterization of phenotypic and genetic variability, it is noteworthy that other aspects regarding the floral architecture, reproductive mode, and gametophyte formation of C. flexuosa have not yet been studied. For this reason, our study encompasses a floral morphoanatomical survey and a comprehensive assessment of gametophyte development in the species. As a result of this study, we report new floral morphotypes, confirming that the morphological variability of the species might be greater than speculated. The morphoanatomy of the androecium and gynoecium and the male and female gametophyte developmental characteristics are uniform in all the populations studied despite the different ploidy levels. Chrysolaena flexuosa has five tetrasporangiate stamens of the dicotyledonous type of development; all the populations studied displayed a unilocular inferior ovary with a single anatropous, unitegumented, and tenuinucellar ovule. Given that all the embryo sacs observed were of the Polygonum-type development regardless of the ploidy level, we infer that the populations analyzed are fertile and undergo sexual reproduction. Our results not only contribute further research in the field of breeding systems and propagation of this species, but also promote the successful introduction of C. flexuosa to the plant ornamental market.
RESUMEN
Climate change has already altered global biodiversity, causing the migration of species and changes in habitat distribution. To implement a sustainable conservation strategy, it is necessary to understand the impacts of climate change on species. Lessingianthus is a South American genus that includes numerous endangered species, some of which grow in the Brazilian Cerrado, a Neotropical savanna considered a world's biodiversity hotspot. However, the impact of global climate change on these species has still not been estimated. We evaluate the effect of climate change on the habitat of 10 threatened Lessingianthus species and on their potential distribution, and assess the effectiveness of current protected areas (PAs) using ecological niche models. Based on the maximum entropy algorithm (Maxent), we first modeled the potential distribution of these species under current climatic conditions and then projected the distribution for two future scenarios of climate change (RCP 4.5 and RCP 8.5) and two time periods (2050 and 2070). We predicted current habitat suitability and identified suitable bioclimatic variables for these species. Our findings suggest that the area comprising the south and southeast of Cerrado is irreplaceable and the most biotically stable region for these endangered species; therefore, it should be considered a conservation priority area.
