Joênes Mucci Peluzio

Divergência genética entre cultivares de soja, sob condições de várzea irrigada, no sul do estado Tocantins

Resumo - Avalia a divergencia genetica entre doze cultivares de soja sob condicoes de varzea irrigada, no Sul do Estado do Tocantins, na Companhia Brasileira de Agropecuaria (Cobrape), em Formoso do Araguaia, na entressafra 2005. O delineamento experimental utilizado foi de blocos casualizados com doze tratamentos e tres repeticoes. Os tratamentos foram constituidos pelas cultivares DM Vitoria, MG/BR 46 (Conquista), Suprema, BRS Pintado, DM 247, BRS/MG 68, BRS/MG Lideranca, BRS/MG Seguranca, DM 339, BRS/MG Garantia, A 7002 e DM 309. Os caracteres estudados foram: producao de graos, numero de sementes/vagem, peso de cem sementes, numero de vagens/planta, numero de dias para o florescimento, numero de dias para maturacao, altura das plantas e altura de insercao da primeira vagem. A divergencia genetica foi avaliada por procedimentos multivariados: distância generalizada de Mahalanobis, metodo de agrupamento de otimizacao de Tocher e metodo do vizinho mais proximo. Os metodos de otimizacao de Tocher e vizinho mais proximo foram concordantes entre si. As caracteristicas numero de dias para a maturidade (39,49%), peso de cem sementes (26,56%) e numero de dias para florescimento (13,59%) foram as que mais contribuiram para a dissimilaridade genetica. A presenca de variabilidade genetica permitiu a identificacao de cultivares dissimilares e com media elevada para os caracteres estudados. As hibridacoes BRS/MG Garantia x DM 339 e BRS/MG Garantia x MG/BR 46 (Conquista) sao promissoras para obtencao de populacoes segregantes com variabilidade superior. Palavras-chave - Glycine Max. Variabilidade. Selecao. Melhoramento genetico.

Reduction of aflatoxin B1 in stored peanuts (Arachis hypogaea L.) using Saccharomyces cerevisiae.

Aflatoxin B(1) is a toxigenic and carcinogenic compound produced by Aspergillus flavus and Aspergillus parasiticus. To inhibit aflatoxin contamination of peanuts, seeds of two peanut breeds, IAC Caiapó and IAC Runner 886, were inoculated with A. parasiticus (1.0 × 10(6) spores per ml) and the yeast Saccharomyces cerevisiae (3.2 × 10(7) cells per ml) and incubated at 25°C for 7 and 15 days. Two experiments were conducted for each incubation period separately. The treatments were completely randomized, with three replications per treatment. Treatments included the two cultivars and three types of inoculation (pathogen alone, yeast and pathogen, and yeast 3 h before pathogen). Aflatoxin B(1) was quantified with a densitometer at 366 nm after thin layer chromatography. Aflatoxin B(1) contamination in peanuts was reduced after the addition of S. cerevisiae. The concentration of aflatoxin B(1) decreased by 74.4 and 55.9% after 7 and 15 days, respectively. The greatest aflatoxin reduction was observed when S. cerevisiae was inoculated 3 h before the pathogen in IAC Caiapó seeds and incubated for 7 days at 25°C. The use of S. cerevisiae is a promising strategy for biological control of aflatoxin contamination in peanuts.

Use of Probiotics to Control Aflatoxin Production in Peanut Grains

Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20) were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1%) followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.). All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains.

Adaptability and stability of soybean cultivars under conditions of varzeas, in Tocantins State Brazil

In order to evaluate the performance of soybean cultivars, three essays were carried out at Formoso do Araguaia, TO,Brazil, in the inter-cropping 2007 (15/05, 30/05 and 12/06). The experimental design employed was a randomized blocks with ten treatments and tree replications. The treatments were composed by ten soybean cultivar (DM Nobre, NIDERA In 7002, DM 247, DM 309, DM 339, M-SOY 8411, M-SOY 8914, M-SOY 8866, M-SOY 9350 and FT 106). In evaluating the performance of cultivars, a study was conducted of adaptability and stability by the methods of Eberhart and Russell (1966) and centroid. The average grain yield varied from 1023 kg ha

Epidemiological and environmental aspects of visceral leishmaniasis in children under 15 years of age between 2007 and 2012 in the City of Araguaína, State of Tocantins, Brazil

INTRODUCTION Visceral leishmaniasis (VL) stands out as a zoonosis observed on four continents and also in urban expansion zones in several regions of Brazil. METHODS A cross-sectional epidemiological study of VL cases in children under 15 years of age in the period from 2007 to 2012. Clinical data were gathered from medical reports; meteorological data were obtained at the Meteorological Measurement Department of UFT. Environmental variables were divided into two periods, rainy and dry. RESULTS The study revealed no difference by gender (p=0.67) among the 821 patients. However, the most affected age group was between one and five years of age (58.6%; p<0.01); the highest prevalence of the disease (99.03%; p<0.01) occurred in urban zones; and the most affected ethnic group (85.5%; p<0.01) was mixed race. The highest incidence coefficients in this population occurred in 2007 and 2008 (578.39/100,000 inhabitants; 18.5/100,000 inhabitants, respectively), whereas the highest lethality coefficients occurred in 2008 and 2011 (0.85/100 deaths). There was no significant correlation between average rainfall and the number of VL cases. The correlation between temperature and number of VL cases was negative (r = -0.4039; p<0.01). CONCLUSIONS In Araguaína, visceral leishmaniasis in children under 15 years is an urban-based endemic disease distributed across all districts of the city wherein temperature as an environmental factor, a higher prevalence in mixed race children between one and five years of age, and a high incidence coefficient all strongly contribute to child mortality.

Reaction of melon genotypes to the gummy stem blight and the downy mildew

The gummy stem blight (Didymella bryoniae) and the downy mildew (Pseudoperonospora cubensis) are two foremost melon (Cucumis melo) diseases, considering their effects on yield and fruit quality. Despite the importance of such diseases, relatively few studies have been done so far on the identification of resistance sources to D. bryoniae and P. cubensis in Brazil. This work aimed at evaluating the resistance of commercial melon genotypes to the gummy stem blight and the downy mildew. Firstly, the most aggressive and representative D. bryoniae isolate was selected. Subsequently, the resistance of 86 melon genotypes to stem infection was studied upon greenhouse conditions by inoculating with the previously selected isolate. Afterwards, the resistance to mildew and leaf infection by D. bryoniae of 28 melon genotypes was evaluated in the field, under natural infection. In the greenhouse, all 86 melon genotypes were infected and showed stem infection symptoms caused by D. bryoniae four days after inoculation. Nevertheless, a significant variation on the resistance levels of the melon genotypes was found. Under field conditions and natural inoculation, genotypes Taslaki and Sary Juliabi were the most susceptible to leaf infection by D. bryoniae, significantly differing from the other genotypes. The lowest levels of susceptibility were identified in genotypes Perlita Busle S1, Valenciano Eliptico, Glaver, MR1, and 2526. All genotypes were susceptible to the downy mildew, albeit differing in susceptibility levels.

Divergência genética entre cultivares comerciais de milho em baixas altitudes no Tocantins, safra 2007/2008

The Tocantins State has good soil and climatic conditions for the development of corn, but has low average productivity, which is mostly attributed to lack of specific genotypes in this environment and incorrect crop management. In this context were evaluated genetic diversity among corn cultivars under different climate conditions in Tocantins. The experiments were conducted in three locations, one in Gurupi-TO and two in Palmas-TO, both experimental areas belonging to the Universidade Federal of Tocantins. The experimental design was randomized blocks with four replications using 24 commercial corn cultivars. Genetic divergence was evaluated by multivariate analysis methods, and cultivars clustered based on the Mahalanobis generalized distance, and then used the Tocher optimization method. The cultivars showed genetic divergence in environment of Palmas-TO early planting, and the characteristics contributions influenced by genotype × environment interaction. Among the cultivars, the open pollination DSSCAMPEAO and BR106 were the most divergent. Among the simple hybrids, DAS2B710 and XGN6370 were the most divergent.

Variabilidade fenotípica e divergência genética em clones de batata doce no estado do Tocantins

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.

Desempenho de populações de milho para produção de grãos e consumo in natura no Estado de Tocantins

A disponibilidade de cultivares destinadas a producao de milho verde e muito escassa, havendo necessidade de se desenvolverem novos hibridos apropriados para esse segmento. O objetivo deste trabalho foi avaliar o desempenho de genotipos de milho visando a producao de graos e o potencial de consumo in natura no Sul do Estado do Tocantins. Os tratamentos foram constituidos de 158 populacoes e duas cultivares comerciais como testemunhas. O delineamento experimental utilizado foi blocos casualizados com quatro repeticoes, sendo avaliados: comprimento de espiga, diâmetro de espiga, formato da espiga, alinhamento de fileiras, cor da coroa do grao, tipo de grao, peso de 100 sementes e produtividade de graos. Houve diferenciacao dos genotipos para todas as caracteristicas e para todas as variaveis ha genotipos com caracteristicas desejaveis visando ao mercado de consumo in natura. De acordo com os resultados, os genotipos 01-5; 02-1; 02-2; 02-3; 02-4; 10-5; 25-1; 32-1 e 34-4 sao os que reunem o conjunto de caracteristicas mais favoraveis para o desenvolvimento de genotipos comerciais voltados para o consumo in natura, e os genotipos do programa de melhoramento de Milho da Universidade Federal do Tocantins possuem potencial produtivo e podem ser utilizados para o desenvolvimento de cultivares voltados para uso nas condicoes edafoclimaticas do Estado do Tocantins. As populacoes avaliadas possuem variabilidade para ser explorada nos programas de melhoramento visando a diferentes aptidoes comerciais.

Genetic divergence and phosphorus use efficiency in the soybean with a view to biodiesel production

The soybean has an important role in the area of biodiesel, due to having a productive potential and technical feasibility able to meet the growing demand for renewable fuels. In the agricultural year of 2009/10, four competitive trials of soybean cultivars were carried out, two on the Campus of Palmas University and the other two on the University Campus at Gurupi, with a study of genetic divergence being undertaken. At each location, the cultivars were trained under conditions of both high and low phosphorus (150 kg ha -1 P 2 O 5 and 30 kg ha -1 P 2 O 5 respectively). The experimental design employed for each trial was of randomised blocks with three replications and 11 treatments. The percentage of oil as a characteristic was studied, and the efficiency of phosphorus usage by the cultivars determined employing the methodology adapted from Fischer (1983). Genetic divergence was evaluated using multivariate procedures: the generalised Mahalanobis distance and Tochers optimisation method for clustering. In the study of genetic divergence, each test represented a distinct variable in the multivariate model. The cultivars M-SOY 9350, M 8766RR and BR/EMGOPA 314 are the most suitable for the production of biodiesel. The hybrids M 8766RR x M 9056RR, BR/EMGOPA 314 x M 9056RR, P98R91 x M 9056RR are promising for obtaining segregating populations to be used for their oil content.