8 research outputs found
Somaclones of mandacaru (Cactaceae) with high morphological divergence may generate new varieties of ornamental cacti
Somaclones of mandacaru cactus (Cereus peruvianus Mill.) with typical and atypical shoots were regenerated from a callus. Since the genetic relationship among regenerated somaclones has not been investigated, current study employed heterologous microsatellite primers to examine the molecular diversity within and among somaclones, showing typical and atypical phenotypes with high morphological divergence. Nei identity value calculated between the somaclones was high (I = 0.929) and AMOVA showed higher genetic variation within (96%) than among (4%) the samples of somaclones. The polymorphism in the microsatellite loci indicated high levels of mean observed and expected heterozygosity in atypical somaclones, presumably with high adaptive potential and as source of genotypes for generation of new varieties of ornamental cacti. On the other hand, low molecular divergence between typical and atypical morphologies of somaclones is a promising perspective for use of the atypical somaclones as source of chemical compounds of commercial and industrial interest. The somaclonal variations occurring in vitro callus culture has generated phenotypically differentiated subpopulations with low molecular divergence, however with high genetic variability, enough to be recommended as a source of genotypes to generate new varieties of ornamental cacti and of plants with new traits, necessary for breeding programs
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Molecular markers for the genetic characterization of Cereus peruvianus Mill. (Cactaceae)
Cereus peruvianus is an ornamental cactus, popularly called "mandacaru" in Brazil, cultivated in gardens and in biological preservation areas. The species is ecologically, economically and industrially important due to the large number of compounds it can produce. Current research estimates the transferability of microsatellite markers of other cactus species to Cereus peruvianus and analyzes the species's genetic diversity. Genetic diversity/similarity has been estimated by Amplified Fragments Length Polymorphism (AFLP) markers in seedlings originated from seeds of different accesses collected at different locations in the states of Paraná, Piauí and São Paulo, Brazil. Thirty-three pairs of microsatellite primers developed from different cactus species were evaluated so that microsatellite markers could be characterized. Five pairs of microsatellite primers developed from Polaskia chichipe, Ariocarpus bravoanus and Echinocactus grusonii were chosen, giving a 15.15% transferability of these primers to C. peruvianus. One of the microsatellites (Pchi47) provided information for 2 loci in the genome and thus 6 microsatellite heterologous loci were evaluated in 13 C. peruvianus accesses. Mean polymorphism for the 13 accesses reached 62.82% and evaluated loci showed 17 alleles at an average of 2.83 alleles per locus. Analysis of genotype frequency suggests a segregation distortion for several loci in which their frequency failed to present a Hardy-Weinberg equilibrium distribution. Fis mean rate (0.4466) indicated a deficit of heterozygotes for the loci under analysis. Differential frequency of certain alleles in the different accesses produced high genetic differentiation (Fst = 0.4260) among them. Genetic diversity analysis of descendents seedlings of 17 C. peruvianus accesses collected at different sites in the state of Paraná, in Picos (in the state of Piauí) and Peruíbe (in the state of São Paulo) was undertaken with six AFLP primers combinations. This analysis showed 348 loci where 282 (81%) polymorphs were. Polymorphism reached 10.42% within the accesses. Nei's genetic differentiation coefficient (Gst=0.7938) and the coefficient from microsatellites showed a higher genetic diversity among the accesses than that withing themselves. This information corroborated the low gene flow (Nm=0.1299). The similarity between the 17 descendants of evaluated seedlings ranged between 0.6193 and 0.9494 and produced a three-group dendrogram, or rather, two groups were made up from different accesses collected in the state of Paraná, whereas the third one was formed by accesses collected in the state of Piauí. The access from the state of São Paulo did not belong to the above groups. Microsatellite and AFLP results suggest a speciation process of the genus Cereus. Consequently, plants that grow in the states of Piauí (Picos), São Paulo (Peruíbe) and Paraná may either be different species of the genus Cereus or a species undergoing a speciation process.Cereus peruvianus é uma espécie de cacto ornamental popularmente conhecida no Brasil como mandacaru. Cultivada em jardins e reservas, esta espécie apresenta importância ecológica, econômica e industrial, devido à grande diversidade de compostos que produzem. Em razão de sua importância, os objetivos do presente trabalho foram estimar a transferibilidade de marcadores microssatélites de outras espécies de cactáceas para Cereus peruvianus e com eles analisar a diversidade genética desta espécie. Estimar a diversidade/similaridade genética utilizando marcadores AFLP (Amplified Fragments Length Polymorphism) em plântulas obtidas a partir de sementes de acessos de diferentes municípios nos estados do Paraná, Piauí e São Paulo, Brasil. Para a caracterização de marcadores microssatélites, foram avaliados 33 pares de primers microssatélites desenvolvidos para diferentes espécies de cactáceas. Desta avaliação, foram selecionados cinco pares de primers microssatélites desenvolvidos para Polaskia chichipe, Ariocarpus bravoanus e Echinocactus grusonii conferindo uma transferibilidade de 15,15% destes primers para C. peruvianus. O microssatélite Pchi47 forneceu informação para dois loci no genoma, desta maneira foram avaliados seis loci heterólogos de microssatélites nas plântulas de C. peruvianus. O polimorfismo médio para as plântulas descendentes dos 13 acessos foi de 62,82%; os loci avaliados apresentaram 17 alelos, com uma média de 2,83 alelos por locus. A análise das freqüências genotípicas indica distorção na segregação para vários loci onde as freqüências destes não apresentam uma distribuição de acordo com o equilíbrio de Hardy-Weinberg. O valor médio de Fis (0, 4466) indica déficit de heterozigotos para os loci estudados. A freqüência diferencial de determinados alelos nas diferentes plântulas obtidas dos acessos demonstrou uma grande diferenciação genética (Fst = 0, 4260) entre os mesmos. A análise da diversidade genética em plântulas descendentes dos 17 acessos de C. peruvianus de diferentes localidades do Paraná, de Picos - PI e de Peruíbe-SP foi realizada com seis combinações de primers AFLP. Este estudo gerou 348 loci, dos quais 282 (81%) foram polimórficos, revelando um polimorfismo médio dentro dos acessos de 10,42%. O coeficiente de diferenciação genética de Nei (Gst=0, 7938), assim como o obtido com microssatélites, revelou maior diversidade genética entre os acessos do que dentro dos mesmos, corroborando o baixo fluxo gênico (Nm=0, 1299). A similaridade entre as plântulas descendentes dos 17 acessos analisados variou de 0, 6193 a 0, 9494 e esses foram organizados em um dendrograma com três grupos, sendo que dois grupos foram formados por diferentes acessos coletados no estado do Paraná e o terceiro grupo constituído por acessos coletados no estado do Piauí. O acesso obtido a partir do estado de São Paulo ficou isolado dos demais grupos. Os resultados obtidos neste trabalho, tanto com microssatélites como com AFLP, sugerem um processo de especiação do gênero Cereus. Portanto, as plantas que crescem nos estados do Piauí (Picos), de São Paulo (Peruíbe) e do Paraná podem corresponder a plantas de espécies diferentes do gênero Cereus, ou pode se tratar de uma espécie em processo de especiação.xi, 129
NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics
Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data
Characterisation of microbial attack on archaeological bone
As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved