Consideraciones sobre la sistemática de las familias y los géneros de plantas vasculares endémicos de Chile

Endemism is one of the main considerations in historical biogeography and one of the most important criteria whenestablishing conservation priorities. Worldwide, more than 90% of the plants listed in conservation categories are endemicto one country. In Chile, 45% of the flora is endemic, currently considering 83 endemic genera and 4 endemic families,elevated numbers compared to the rest of Latinamerica. However, the high rate of changes in taxonomy, based on studiesof molecular systematics has produced modifications in this list. This study aims at discussing such modifications and inthis way, contribute to the correct delimitation of our endemic genera. Using updated databases and bibliographic sources,an exhaustive revision of these genera was carried out. Genera with registries outside of the country, as well as those thathad enough evidence to change their taxonomic status were subtracted from the list. A critical revision of the systematicbibliography available is provided, emphasizing the discussion on those genera with ambiguous classification status.El endemismo es uno de los principales aspectos que trata la biogeografía histórica y es uno de los criterios más importantespara establecer las prioridades de conservación de las especies. En el mundo, más del 90% de las plantas que se encuentraen alguna categoría de amenaza son endémicas de un sólo país. En Chile, un 45% de las especies de plantas vascularesson endémicas. Actualmente este número incluye 83 géneros y 4 familias endémicas del país; éstos son valores elevadosen comparación con el resto de Latinoamérica. Sin embargo, la alta tasa de cambios producidos por los estudios desistemática molecular en la taxonomía ha generado modificaciones en estos números. Este trabajo pretende discutirdichas modificaciones y así contribuir a la correcta delimitación de estos géneros endémicos. Utilizando bases de datos ybibliografía actualizadas, se llevó a cabo una revisión exhaustiva sobre estos géneros. Se sustrajeron de la lista aquellosgéneros con registros fuera del país y aquellos que cuentan con evidencia suficiente para cambiar su estatus taxonómico. Seentrega una revisión crítica de la bibliografía sistemática respecto de los géneros en cuestión, discutiendo principalmenteaquellos que a la luz de la literatura presentaron ambigüedades en su clasificación

A link between evolution and society fostering the UN sustainable development goals

Given the multitude of challenges Earth is facing, sustainability science is of key importance to our continued existence. Evolution is the fundamental biological process underlying the origin of all biodiversity. This phylogenetic diversity fosters the resilience of ecosystems to environmental change, and provides numerous resources to society, and options for the future. Genetic diversity within species is also key to the ability of populations to evolve and adapt to environmental change. Yet, the value of evolutionary processes and the consequences of their impairment have not generally been considered in sustainability research. We argue that biological evolution is important for sustainability and that the concepts, theory, data, and methodological approaches used in evolutionary biology can, in crucial ways, contribute to achieving the UN Sustainable Development Goals (SDGs). We discuss how evolutionary principles are relevant to understanding, maintaining, and improving Nature Contributions to People (NCP) and how they contribute to the SDGs. We highlight specific applications of evolution, evolutionary theory, and evolutionary biology's diverse toolbox, grouped into four major routes through which evolution and evolutionary insights can impact sustainability. We argue that information on both within-species evolutionary potential and among-species phylogenetic diversity is necessary to predict population, community, and ecosystem responses to global change and to make informed decisions on sustainable production, health, and well-being. We provide examples of how evolutionary insights and the tools developed by evolutionary biology can not only inspire and enhance progress on the trajectory to sustainability, but also highlight some obstacles that hitherto seem to have impeded an efficient uptake of evolutionary insights in sustainability research and actions to sustain SDGs. We call for enhanced collaboration between sustainability science and evolutionary biology to understand how integrating these disciplines can help achieve the sustainable future envisioned by the UN SDGs

Spatial phylogenetics of the native woody plant species in Hainan, China

To better identify biodiversity hotspots for conservation on Hainan Island, a tropical island in southern China, we assessed spatial variation in phylogenetic diversity and species richness using 18,976 georeferenced specimen records and a newly reconstructed molecular phylogeny of 957 native woody plants. Within this framework, we delineated bioregions based on vegetation composition and mapped areas of neoendemism and paleoendemism to identify areas of priority for conservation. Our results reveal that the southwest of Hainan is the most important hot spot for endemism and plant diversity followed by the southeast area. The distribution of endemic species showed a scattered, rather than clustered, pattern on the island. Based on phylogenetic range-weighted turnover metrics, we delineated three major vegetational zones in Hainan. These largely correspond to natural secondary growth and managed forests (e.g., rubber and timber forests) in central Hainan, old-growth forests and natural secondary growth forest at the margins of Hainan, and nature reserves on the island (e.g., Jianfeng and Diaoluo National Nature Reserves). Our study helps to elucidate potential botanical conservation priorities for Hainan within an evolutionary, phylogenetic framework

Analysis of KCS2 : a gene encoding a new condensing enzyme for the elongation of very long chain fatty acids in Arabidopsis thaliana

Condensing enzymes for very long chain fatty acid (VLCFA) synthesis catalyze the first of a series of four reactions that elongate the growing acyl chain by two carbons at a time. It has been shown that the activity of the condensing enzyme determines the amount and acyl chain length of the VLCFAs produced by a fatty acid elongation system. My research project focused on the characterization of KCS2, a new putative condensing enzyme of Arabidopsis thaliana. Computer database analyses showed that the KCS2 gene is located directly upstream of the FAE1 gene, the first condensing enzyme for the elongation of VLCFAs to be studied in Arabidopsis, suggesting a gene duplication phenomenon. Analysis of the expression pattern of KCS2 showed that the gene was primarily expressed in the anthers of Arabidopsis flowers. The ability of the condensing enzyme to elongate VLCFAs was determined by expressing it in yeast and in seeds of CB25, an Arabidopsis mutant defective in VLCFA elongation in the seed. In both systems, KCS2 was able to catalyze the elongation of VLCFAs. However, the accumulating products of fatty acid elongation carried out by the KCS2 condensing enzyme differed in the two organisms. Yeast accumulated preferentially saturated VLCFAs from C20:0 to C26:0, whereas Arabidopsis seeds accumulated primarily mono-unsaturated VLCFAs, C20:1 and C22:1. Finally, in an attempt to generate co-suppressed plants to determine the function of the KCS2 condensing enzyme, the KCS2 gene was transformed into Arabidopsis plants under the control of the CaMV35S promoter. No visible phenotype was obtained. However, some lines that were over-expressing the gene were able to synthesize more VLCFAs in the seed when compared to the wild type. In contrast, total wax load in stems of 35S-KCS2 over-expressors was not increased. Moreover, there was no correlation between the level of expression of the transgene and the amount of total wax produced. The specific function of the KCS2 condensing enzyme requires further study.Science, Faculty ofBotany, Department ofGraduat

Micromorphology and anatomy of leaves of 'Syzygium floribundum' (Myrtaceae: Syzygieae), a rainforest tree endemic to eastern Australia

Although species of Syzygium are abundant components of the rainforests in Queensland and New South Wales, little is known about the anatomy of the Australian taxa. Here we describe the foliar anatomy and micromorphology of Syzygium floribundum (syn: Waterhousea floribunda) using standard protocols for scanning electron microscopy (SEM) and light microscopy. Syzygium floribundum possesses dorsiventral leaves with cyclo-staurocytic stomata, single epidermis, internal phloem, rhombus-shaped calcium oxalate crystals and complex-open midrib. In general, leaf anatomical and micromorphological characters are common with some species of the tribe Syzygieae. However, this particular combination of leaf characters has not been reported in a species of the genus. The anatomy of the species is typical of mesophytic taxa

Arthropod-Microbiota Integration: Its Importance for Ecosystem Conservation

International audienceRecent reports indicate that the health of our planet is getting worse and that genuine transformative changes are pressing. So far, efforts to ameliorate Earth’s ecosystem crises have been insufficient, as these often depart from current knowledge of the underlying ecological processes. Nowadays, biodiversity loss and the alterations in biogeochemical cycles are reaching thresholds that put the survival of our species at risk. Biological interactions are fundamental for achieving biological conservation and restoration of ecological processes, especially those that contribute to nutrient cycles. Microorganism are recognized as key players in ecological interactions and nutrient cycling, both free-living and in symbiotic associations with multicellular organisms. This latter assemblage work as a functional ecological unit called “holobiont.” Here, we review the emergent ecosystem properties derived from holobionts, with special emphasis on detritivorous terrestrial arthropods and their symbiotic microorganisms. We revisit their relevance in the cycling of recalcitrant organic compounds (e.g., lignin and cellulose). Finally, based on the interconnection between biodiversity and nutrient cycling, we propose that a multicellular organism and its associates constitute an Ecosystem Holobiont (EH). This EH is the functional unit characterized by carrying out key ecosystem processes. We emphasize that in order to meet the challenge to restore the health of our planet it is critical to reduce anthropic pressures that may threaten not only individual entities (known as “bionts”) but also the stability of the associations that give rise to EH and their ecological functions

Foliar micromorphology and anatomy of Ugni molinae Turcz. (Myrtaceae), with particular reference to schizogenous secretory cavities

Background\ud \ud Ugni molinae Turcz. is one of the most studied species of South American Myrtaceae due to its edible\ud fruits and foliar medicinal compounds. However, there is no anatomical study of the leaves or secretory cavities.\ud This paper seeks to describe the leaf micromorphology and anatomy of the species using standard protocols for\ud light and scanning electron microscopy. Secretory cavities were anatomically characterized in young and mature\ud leaves. Histochemical staining of the cavities was performed.\ud \ud Results\ud \ud The leaves of U. molinae are hypostomatic, have a wavy surface and possess scattered hairs. Leaf\ud anatomical features include dorsiventral mesophyll, two to three layers of palisade parenchyma with abundant\ud chloroplasts, calcium oxalate crystals and internal phloem in vascular bundles. Schizogenous secretory cavities are\ud present on the abaxial surface and are mainly located on the margins of the leaves. Histochemical tests of these\ud cavities suggest the presence of lipophilic substances.\ud \ud Conclusions\ud \ud This is the first study of secretory cavities in Chilean Myrtaceae. In general, micromorphological and\ud anatomical characters are similar to other species of the family. The present findings could provide valuable\ud anatomical information for future research in South American Myrtaceae

Evolutionary diversity of the endemic genera of the vascular flora of Chile and its implications for conservation.

As a direct consequence of global change, both natural and human-induced, a high percentage of biodiversity is now under threat worldwide. This has urged conservation planners to formulate and/or improve existing strategies to preserve species and their ecosystems. In this context, the present study focuses on two strategies using phylogeny-based measures of biodiversity to account for the processes that led to the biodiversity patterns observed today. It will contribute additional information that can aid decision-making regarding the assignment of threat status for some species, thus strengthening measures currently in use and facilitate the allocation of often scarce conservation resources. The Evolutionarily Distinct (ED) index prioritises species that are on long branches of the tree of life with few descendants, and the Evolutionarily Distinct and Globally Endangered (EDGE) index integrates evolutionary history with IUCN Red List threat status of species. It has been used mostly in animal groups, but since the threats faced by many plants have not been evaluated, it has been more difficult to compile for plants worldwide. Here, we apply the EDGE metric to species of the endemic genera of Chile. However, more than 50% of the endemic flora of the country are still lacking official threat status. We thus used an alternative measure (Relative Evolutionary Distinctness–RED), based on a range-weighted phylogenetic tree, which uses geographic ranges to adjust branch lengths, and calculate ED. The RED index was shown to be a suitable measure, yielding similar results compared to EDGE, at least for this group of species. Given the urgency to halt biodiversity loss and the time it would take to evaluate all species, we propose that this index is used to set conservation priorities until we can calculate EDGE for these unique endemic species. This would allow guiding decision-making until we can gather more data to assess and assign conservation status to new species

A new species of Diplostephium (Asteraceae, Astereae) from the Atacama Desert, Chile

A new species, Diplostephium paposanum S.T.Ibáñez & Muñoz-Schick, sp. nov., is described for Chile, extending the southern distribution of the genus. Its position within the genus was confirmed by morphological and molecular data, discussed here. The new species was found in a coastal environment, new to the genus, and is geographically far removed from the other Chilean species, which are from the Andes. The formation where it occurs, known as lomas, acts as a biodiversity refuge in hyperarid environments. The presence of D. paposanum in this environment contributes to the evidence of a floristic connection between the Atacama Desert and the Neotropical Andes