ABSTRACT Forest-to-agriculture conversion and soil management practices for soybean cropping are frequently performed in the Cerrado (Brazilian tropical savanna). However, the effects of these practices on the soil microbial communities are still unknown. We evaluated and compared the fungal community structure in soil from soybean cropland with soil under native Cerrado vegetation at different times of the year in the Tocantins State. Soil samples were collected in two periods after planting (December) and in two periods during the soybean reproductive growth stage (February). Concomitantly, soil samples were collected from an area under native Cerrado vegetation surrounding the agricultural area. The soil DNA was analyzed using a fingerprinting method termed Automated Ribosomal Intergenic Space Analysis (ARISA) to assess the fungal community structure in the soil. Differences in the fungal community structure in the soil were found when comparing soybean cropland with the native vegetation (R = 0.932 for sampling 1 and R = 0.641 for sampling 2). Changes in the fungal community structure after management practices for soybean planting in Cerrado areas were related to changes in soil properties, mainly in copper, calcium, and iron contents, cation exchange capacity, base saturation, and calcium to magnesium ratio. These results show the changes in the fungal community structure in the soil as an effect of agricultural soil management in Cerrado vegetation in the state of Tocantins.

Com objetivo de avaliar a variabilidade fenotípica e a divergência genética entre 50 clones de batata doce, foi realizado um ensaio na Estação Experimental da Universidade Federal do Tocantins - Campus de Palmas, no ano agrícola 2009/2010. A divergência genética foi avaliada pelo método de agrupamento de otimização de Tocher. As características estudadas foram produtividade, produção de matéria seca, teor de amido e rendimento de etanol. O método de otimização por Tocher separou os clones em oito grupos geneticamente distintos. As características produtividade (70,15%) e rendimento em etanol (15,06%) foram as que mais contribuíram na divergência genética entre os clones. A presença de variabilidade genética permitiu a identificação de cultivares dissimilares e com média elevada indicando a possibilidade de seleção de genótipos superiores para as características estudadas. Os cruzamentos Duda x 22.19, Marcela x 22.19, Barbara x 22.19, Duda x Barbara, Amanda x 22.19, Amanda x Marcela são promissores para obtenção de híbridos divergentes.

In order to evaluate the phenotypic variability and genetic divergence between 50 clones of the sweet potato, a test was conducted at the Experimental Station of the Federal Universidade of Tocantins, Palmas Campus, in the agricultural year of 2009/2010. The genetic diversity was assessed using the Tocher grouping optimization method. The characteristics studied were productivity, dry matter production, starch content and ethanol yield. The Tocher optimization method separated the clones into eight genetically distinct groups. The characteristics of productivity (70.15%) and ethanol yield (15.06%) were those that most affected genetic divergence among the clones. The presence of genetic variability permitted the identification of dissimilar cultivars with a high average, indicating the possibility of selecting superior genotypes for the traits studied. The Duda x 22.19, Marcela x 22.19, Barbara x 22:19, Duda x Barbara, Amanda x 22:19, Amanda x Marcela crossbreeds are those which are promising for obtaining divergent hybrids.

Avaliou-se a ocorrência de Leishmania infantum em cães do município de Palmas-TO, comparando dados diagnósticos obtidos pela Reação em Cadeia da Polimerase (PCR) e pelo diagnóstico parasitológico. Foram coletadas amostras de sangue e de aspirado de linfonodo de 63 cães machos e fêmeas, várias idades e raças, domiciliares ou não de agosto de 2009 a junho de 2010. As lâminas contendo esfregaço dos aspirados de linfonodos foram coradas pelo corante Giemsa. Na PCR, a sequência alvo de 145 pb do fragmento LT1, situado no minicírculo do kDNA do grupo Leishmania donovani, foi detectada através dos oligonucleotídeos iniciadores RV1 e RV2. O teste χ² (Qui-quadrado), demonstrou haver relação significativa entre a sintomatologia e a positividade dos cães para Leishmaniose Visceral (LV). O exame parasitológico mostrou uma concordância de 66,7% com a PCR em sangue e 84,1% com a PCR de aspirado de linfonodo. Além destas análises, houve a avaliação dos diagnósticos em paralelo e em série, onde as concordâncias com o exame parasitológico foram de 76,2% e 74,6%, respectivamente. Os resultados permitem sugerir a utilização da PCR de linfonodos na avaliação de grandes populações (inquéritos), e o exame parasitológico para a avaliação clínica inicial em consultórios veterinários.

This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In PCR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices.