Rhizobial diversity from stem and root nodules of Discolobiumand Aeschynomene.

Among the genera that exhibit stem nodulation, Aeschynomeneand Discolobiumare found in the Pantanal Mato-grossense (wetlands in the state ofMato Grosso, Brazil). Isolates obtained from the stem and root nodules of D. pulchellum, D. psoraleaefolium, D. leptophyllumand A. fluminensiswere collected from various locations in the Pantanal de Poconésub-region and phenotypically characterized and genotyped by restriction analysis of the 16S rDNA gene. Of the 282 isolates obtained from the stem and root nodules, 84.3% alkalized YMA media and 74.1% showed slow growth. No differences in either the phenotype or the genotype among the rhizobial populations isolated from the root or stem nodules of the species Discolobiumand A. fluminensis were observed. Among the isolates obtained from D. pulchellum,there was a group that was not similar to any of the reference strains used, and most of the isolates analyzed by PCR-RFLP were similar to the genus Bradyrhizobium

Trypanosomatid prevalence in Nezara viridula (L.), Euschistus heros (Fabricius) and Piezodorus guildinii (Westwood) (Heteroptera: Pentatomidae) populations in Northern Paraná, Brazil.

The stink bug complex in soybeans has a great potential to cause damage, their control has been difficult due to high population densities at the end of the season. Studies related to entomopathogenic organisms in stink bugs are interesting for their possibilities to be used as biological control agents and because they could be an etiological agent in mass rearing. We determined the prevalence of trypanosomatids in the most important species of the stink bugs complex in soybean, from Brazil, Nezara viridula (L.) Euschistus heros (Fabricius) and Piezodorus guildinii (Westwood). Insects were collected in soybean and on alternate hosts during the intercrop season. Hemolymph drops fromeach adult were mounted on slides and observed under microscope: stink bug numbers with and without flagellates were recorded. The flagellates found in P. guildinii or E. heros populations were smaller than that found in N. viridula. The higher prevalence of the trypanosomatids was observed on soybean reaching a peak of 30% of the sampled N. viridula specimens in January, 2001, and 44% prevalence in February, 2003. The maximum prevalences (16%) in P. guildinii were observed in January and February, 2003 and on July 27, 2003 with 20% of the specimens infected. Flagellates in the hemolymph of E. heros were less frequent (maximum prevalence of 8.7%), suggesting that this species is less susceptible than N. viridula and P. guildinii. Trypanosomatid prevalence was higher than that observed for entomopathogenic fungi, however they seem to be inefficient control agents in short term condition

Padrão de fermentação das silagens de seis genótipos de milho.

Foram avaliados os padroes de fermentacao das silagens de seis genotipos de milho plantados na EMBRAPA Milho e Sorgo. Os silos experimentais foram abertos com um, tres, cinco, sete, 14 e 28 dias apos ensilagem. Foram analisados o pH e nitrogenio amoniacal (N-NH3/NT) no suco das silagens e materia seca (MS), proteina bruta (PB) e digestibilidade in vitro (DIVMS) nas amostras secas em estufa. A MS permaneceu estavel; pH declinou ate o quinto dia de fermentacao e estabilizou-se. A PB foi maior no hibrido AG5011 (8,57%); teores de DIVMS mantiveram-se estaveis durante a fermentacao, variando de 57,3 a 60,2%; concentracoes de N-NH3/NT aumentaram com o avanco da ferementacao

Composição química da planta verde e das silagens de doze cultivares de milho.

Doze cultivares de milho foram colhidos e ensilados na EMBRAPA - milho e sorgo. O material original e as silagens foram analisados em relacao ao teor de proteina bruta, FDN e FDA. Em relacao a proteina bruta o cultivar AG5011 foi superior no material original e na silagem. Na analise de FDN o cultivar P3041 participou do grupo significativamente inferior no material original e do grupo superior na silagem. Quanto ao teor de FDA, os cultivares C701 e P3041 participaram do grupo significativamente inferior ao material original, sendo que nao ocorreu alteracao significativa no teor de FDA com a ensilagem

Características agronômicas de 12 cultivares de milho para silagem.

Foram avaliados quanto a proporcoes de espiga, colmo, folhas e producao de materia seca doze cultivares de milho no laboratorio de nutricao animal da EV-UFMG foram analisadas a materia seca e a digestibilidade in vitro dos cultivares. Em relacao as fracos da planta nao foram observadas diferencas estatisticas entre os materiais. Os cultivares C701 e P3041 foram significativamente superiores aos outros em relacao a producao demateria seca digestivel por hectare

Parasitic infections in pirarucu fry, Arapaima gigas Schinz, 1822 (Arapaimatidae) kept in a semi-intensive fish farm in Central Amazon, Brazil.

Studies regarding parasite fauna in farmed fish are of great relevance to lhe knowledge of the parasites species. allowing interference in their proliferation in order to avoid epizooties and consequently. economical losses, This study was designed to investigate the prevalence and intensity of parasites in fry Arapaima gigas maintained in ponds of a semi-intensive fish farm in Amazonas State, Brazil. On necropsy, 96,0% of A. gigas were found parasitized by Dawestrema cycloancistrioides. Dawestrema cycloancistrioides (Monogenoidea). Trichodina sp., Ichthyobodo sp. (Protozoa). Camallamus tridentatus, Terranova serrata, Goezia spinulosa (Nematoda) and Argulidae. However, D. cycloancistrium. D, cycloancistrioides and Trichodina fariai were the parasites of' greatest intensity. This study is the first to report parasitic infections in farmed A. gigas and the results indicated a high rate of infection that might lead to important changes in the health of the hosts