RESUMO
Measures to control maize white spot (MWS) caused by Pantoea ananatis are preferentially based on resistant cultivars. A lack of knowledge on the genetic variability of pathogens could interfere with the development and utilization of controlling strategies in this pathosystem. The main goals of this study were to investigate the genetic variability of 90 P. ananatis isolates from three different eco-geographical regions of Brazil by amplified fragment length polymorphism (AFLP), and to determine the presence of a universal P. ananatis plasmid in isolates from tropical Brazil. Analysis of genetic similarity by AFLP allowed us to categorize the 90 isolates into two groups. However, no correlation between the collecting sites and genetic groupings was observed. The polymorphism percentage found in P. ananatis ranged between 24.64 and 92.46%, and genetic diversity was calculated to be 0.07-0.09. The analysis of molecular variance showed that 99.18% of genetic variability was within the populations, providing evidence that evolutionary forces were acting on these populations. All P. ananatis isolates showed the P. ananatis universal plasmid (280 or 352 kb). This is the first report on the presence of a universal P. ananatis plasmid from MWS lesions in the tropical area.
Assuntos
Pantoea/classificação , Doenças das Plantas/microbiologia , Zea mays/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Brasil , DNA Bacteriano/genética , DNA Ribossômico/genética , Evolução Molecular , Variação Genética , Pantoea/genética , Pantoea/isolamento & purificação , Doenças das Plantas/genética , Plasmídeos/genéticaRESUMO
Phyla scaberrima (Verbenaceae) is a herbaceous species distributed from Mexico to Panama. Because of its well-known sweet properties and other medicinal uses, this species is cultivated in South America and the Caribbean. Phyla scaberrima has been arbitrarily extracted from nature, resulting in a severe reduction in its gene pool. In this study, we developed and characterized 11 simple sequence repeat markers for P. scaberrima to determine the genetic variability and patterns of population structure of the species. Fifty-six alleles were detected in a sample of 48 individuals belonging to 3 different populations. The average number of alleles per locus was 5.09, while the polymorphic information content ranged from 0.000-0.587. The observed and expected heterozygosities varied from 0.000-0.543 and from 0.000-0.651, respectively. Two loci exhibited significant deviation of the expected Hardy-Weinberg proportion. The 11 primer pairs were also tested for cross-amplification to 6 species of the related genus Lippia. The transferability rate ranged from 4 loci in Lippia florida and L. rotundifolia to 6 loci in L. corymbosa and L. microcephala. The 11 primer sets were shown to be valuable tools for population genetic studies in P. scaberrima and in species of the genus Lippia in which primer transferability was detected.
Assuntos
Repetições de Microssatélites , Verbenaceae/genética , Sequência de Bases , Primers do DNA , Genes de Plantas , Marcadores Genéticos , Reação em Cadeia da PolimeraseRESUMO
Chrysophyllum gonocarpum is a tropical tree species that is very important in the recovery of heterogeneous forests and of degraded areas of permanent preservation. We identified microsatellite loci for C. gonocarpum to assess the genetic variability and the patterns of the population structure of the species. We isolated 8 microsatellite primers by using CT- and GT-enriched genomic libraries. We detected 2-4 alleles with 2.9 alleles per locus on average, by polymerase chain reaction. Test for cross-amplification showed that some loci were successfully amplified in 2 other Chrysophyllum species. The microsatellites can be used to assess the genetic diversity and population structure of C. gonocarpum. Some primer pairs can be amplified in C. marginatum and C. splendens.
Assuntos
DNA de Plantas/genética , Repetições de Microssatélites , Sapotaceae/genética , Alelos , Variação Genética , Biblioteca Genômica , Reação em Cadeia da Polimerase/métodosRESUMO
In the context of the high application potentials for on-line measurements in wastewater quality monitoring, UV spectroscopy has received recent attention. In the present work UV spectrophotometric analyses were coupled to principal component analysis (PCA) and cluster analysis (CA) to characterize samples taken from a fuel park wastewater treatment plant and to attempt preliminary contaminant identification in the treated wastewater. The score plot resulting from PCA identified two different groups of spectra, one including the influents to the biological reactor and the other the treated wastewater samples. Among the latter, weekday and weekend samples could be further distinguished. The same groups of samples were identified in a dendrogram from CA. The score plot and the dendrogram also allowed the tentative identification of employed process chemicals (lubricant and detergents) as residual contaminants in the treated effluent.
Assuntos
Monitoramento Ambiental/métodos , Resíduos Industriais , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Água/análise , Análise por Conglomerados , Análise de Componente Principal , Espectrofotometria Ultravioleta/métodos , Eliminação de Resíduos LíquidosRESUMO
Este estudo objetivou identificar as espécies arbóreas medicinais das matas ciliares de três pequenas propriedades rurais do município de Urubici-SC, e estabelecer relações entre as características ecológicas das mesmas com as possibilidades de emprego para restauração de ambientes ciliares degradados. Empregou-se o método dos quadrantes, para levantamento dos indivíduos com CAP>15 cm. Os indivíduos amostrados foram herborizados, depositados no Herbário LUSC e categorizados quanto ao uso medicinal, parte usada, freqüência, síndrome de dispersão (anemocórica, autocórica e zoocórica), grupo ecológico (pioneira, secundária inicial, secundária tardia) e uso para restauração florestal. Dos 240 indivíduos amostrados, 197 indivíduos pertencentes a 22 espécies de 15 famílias botânicas apresentaram potencialidades medicinais. As famílias Euphorbiaceae, Rosaceae, Myrtaceae, Sapindaceae, Lauraceae e Anacardiaceae foram as mais abundantes. Mais de 85 por cento das espécies com potencial medicinal amostradas apresentaram síndrome de dispersão zoocórica; cerca de 78 por cento foram incluídas nos grupos ecológicos das secundárias iniciais e pioneiras e cerca de 88 por cento são recomendadas para restauração. As espécies arbóreas medicinais são bastante freqüentes nas matas ciliares degradadas do Rio Canoas, podendo ser fonte de recursos genéticos para a restauração e adequação das APPs à legislação ambiental, além de se constituírem em produtos florestais não madeireiros passíveis de exploração.
This study aimed to identify the medicinal arboreal species from riparian forests at three small farms in Urubici Municipality, Santa Catarina State, Brazil, and relate their ecological features to the possibilities of their use for restoration of degraded riparian environments. In order to survey individuals with circumference at breast height (CBH) >15 cm, the quadrant method was adopted. The sampled specimens were herborized, incorporated into the Herbarium LUSC and categorized according to their medicinal use, employed part, frequency, dispersal syndrome (anemochory, autochory and zoochory), ecological group (pioneer, early secondary, late secondary) and use for forest restoration. Of the 240 sampled specimens, 197 belonging to 22 species of 15 families were potentially medicinal. The most abundant families were Euphorbiaceae, Rosaceae, Myrtaceae, Sapindaceae, Lauraceae and Anacardiaceae. More than 85 percent potentially medicinal species had zoochoric dispersal syndrome, around 78 percent were categorized as early secondary and pioneer, and around 88 percent were recommended for restoration. Medicinal arboreal species are quite common in degraded riparian forests along Canoas River. They can provide genetic resources for restoration and adequacy of permanent preservation areas (PPAs) to the environmental legislation; moreover, they are exploitable non-timber forest products.