Os herbicidas pertencentes ao grupo químico das imidazolinonas apresentam características físico-químicas que lhes permitem persistir no ambiente por longos períodos. Assim, objetivou-se com este trabalho avaliar o potencial de espécies cultivadas como pastagens, cobertura verde no inverno e/ou produtoras de grãos em remediar solos contaminados com imazethapyr + imazapic e imazapyr + imazapic, usados para o controle de plantas daninhas em lavouras de arroz irrigado. Para isso, o experimento foi conduzido em delineamento inteiramente casualizado com quatro repetições. As espécies Lolium multiflorum, Lotus corniculatus, Trifolium repens, Festuca arundinaceae, Vicia sativa e Brassica napus foram submetidas à aplicação de herbicidas em diferentes doses. Os herbicidas imazethapyr + imazapic e imazapyr + imazapic foram aplicados nas doses de 0,0, 1,0 e 2,0Lha-1 e de 0,0, 140 e 280gha-1, respectivamente, em pré-emergência das espécies. Os resultados demonstram que B. napus e F. arundinaceae não são tolerantes aos herbicidas, apresentando 100% de fitotoxicidade (morte das plantas), para todas as doses avaliadas. O herbicida imazapyr + imazapic demonstrou ser menos seletivo, tendo ocasionado os maiores índices de fitotoxicidade nas espécies testadas. V. sativa foi mais tolerante aos herbicidas podendo ser a mais indicada para os programas de fitorremediação em áreas contaminadas com imazethapyr + imazapic e imazapyr + imazapic.

Imidazolinone herbicides present physicochemical characteristics that allow them to persist longer in environment, with increased chances of soil and water contamination, as well as carryover effects on subsequent crops. Phytoremediation is shown as a promising technique to decontaminate soils polluted by herbicides. The aim of this study was to assess the potential of some winter grown species in removing residuals from soils contaminated with imazethapyr + imazapic and imazapic + imazapyr, using pre-emergence to control weeds in summer grown rice fields. The experiment was conducted in a completely randomized design, with four replications. All species were subjected to herbicide application at different doses. Imazethapyr + imazapic and imazapyr + imazapic were applied at doses of 0.0, 1.0 and 2.0 L ha-1, and 0.0, 140 and 280 g ha-1, respectively, in pre-emergence of the species. Brassica napus and Festuca arundinaceae are not tolerant to herbicides, with 100% of phytotoxicity (plant death) for all doses assessed. The herbicide imazapyr + imazapic proved to be less selective, causing the highest phytotoxicity in the species tested. The most tolerant species to the herbicides was Vicia sativa, which may be the most suitable one for phytoremediation programs in areas contaminated with imazethapyr + imazapic and imazapyr + imazapic.

Objetivou-se com este trabalho avaliar a resposta competitiva de genótipos de arroz na presença de um biótipo de papuã (Brachiaria plantaginea), em diferentes proporções de plantas na associação. O delineamento experimental adotado foi o completamente casualizado com quatro repetições. Os tratamentos foram arranjados em série de substituição e constituíram-se de cinco proporções de plantas de arroz e do papuã na associação (100:0, 75:25, 50:50, 25:75 e 0:100). Aos 50 dias após a emergência das espécies, efetuou-se a aferição do perfilhamento, da estatura, da área foliar e da massa seca da parte aérea das plantas de arroz e de papuã. Foi observada competição entre os genótipos de arroz e o papuã, sendo ambos afetados negativamente, independentemente da proporção de plantas testada, provocando, em todos os casos, redução das variáveis avaliadas. Ocorreu diferenciação da habilidade competitiva entre os genótipos de arroz, quando na presença da planta daninha. O genótipo BRS Sinuelo CL foi mais competitivo quando se analisou a massa seca e área foliar, ao passo que o BRS Querência sobressaiu em relação ao BRS Sinuelo CL para o perfilhamento. O papuã apresenta elevada habilidade competitiva com o arroz irrigado, necessitando de controle para que não venha afetar negativamente o crescimento e o desenvolvimento da cultura.

With this study, we aimed to evaluate the competitive ability of rice genotypes in the presence of Alexandergrass (Brachiaria plantaginea) in different proportions. Experiments were performed in a completely randomized design with four replications. Treatments were arranged in a substitution series consisting of five rice to Alexandergrass ratios, respectively, as follows: 100:0, 75:25, 50:50, 25:75 and 0:100. At fifty days after emergence, measurements of plant tillering, height, leaf area and shoot dry mass of both rice and Alexandergrass were performed. Results indicated competition between rice and Alexandergrass, both being affected regardless of the plant ratio, resulting in a reduction of variables. There were differences in the competitive ability between rice genotypes in the presence of the weed. BRS Sinuelo CL was more competitive regarding dry mass and leaf area, while BRS Querencia surpassed BRS Sinuelo CL for tillering. Alexandergrass has a high competitive ability against rice, demanding the application of control practices in order avoid a negative impact on rice growth and development.

Giardia duodenalis is a complex species that comprises at least seven distinct genetic groups (A to G), but only genotypes A and B are known to infect humans and a wide variety of other mammals. Regardless of biological, biochemical and antigenic analysis, several isolates maintained in vitro were not genetically typed yet. So, in the present study, five Brazilian axenic isolates obtained from asymptomatic and symptomatic patients were typed in order to determine the major genetic groups to which the isolates belonged. DNA was extracted from axenic trophozoites, fragments of glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes were amplified by PCR and the isolate genotyping was carried out using restriction fragment length polymorphism (RFLP) and DNA sequencing for both genes. The results revealed that all isolates were assigned to genotype A at both analyzed loci. Indeed, DNA sequence analysis classified the four isolates obtained from asymptomatic individuals into subtype AII, while the isolate obtained from the symptomatic patient was typed as subtype AI. Despite of the limited number of isolates assessed, the findings presented herein provide interesting insights on the occurrence of Giardia genotypes in Brazil and hold the perspective for future molecular and epidemiological investigations.

The present study was designed to estimate the prevalence of Giardia infection in preschool- and school-aged children living in an endemic area. Fecal samples from 573 children were processed by zinc sulfate centrifugal flotation, centrifugal sedimentation (using a commercial device for fecal concentration - TF-Test kit®) and polymerase chain reaction (PCR)-based methods. Of the stool samples assessed, 277 (48.3%) were positive for intestinal parasites and/or commensal protozoa. Centrifugal flotation presented the highest diagnostic sensitivity for Giardia infections. The kappa index revealed that both coproparasitological techniques closely agreed on the Giardia diagnosis (86%) versus satisfactory (72%) and poor (35%) concordances for commensal protozoan and helminth infections, respectively. Concerning Giardia molecular diagnosis, from the 71 microscopy-positive samples, specific amplification of gdh and tpi fragments was noted in 68 (95.7%) and 64 (90%) samples, respectively. Amplification of gdh and tpi genes was observed, respectively, in 95.7% and 90% of microscopy-positive Giardia samples. For 144 microscopy-negative samples, gdh and tpi gene amplification products were obtained from 8.3% and 35.9% samples, respectively. The agreement between these genes was about 40%. The centrifuge-flotation based method was the most suitable means of Giardia diagnosis assessed in the present study by combining accuracy and low cost.

A recombinação somática em células diplóides heterozigotas pode atuar como agente promotor de neoplasias por induzir homozigose de genes deletéreos. Por meio desse processo, genes supressores de tumores podem ser completamente suprimidos em células recombinantes. O presente trabalho avaliou a genotoxicidade do detergente derivado do óleo da semente da mamona (Ricinus communis) em células diplóides heterozigotas do fungo filamentoso Aspergillus nidulans. Trabalhos anteriores avaliaram a aplicação dessa solução no tratamento de canais radiculares como líquido irrigador. O potencial recombinagênico desse composto foi estudado pela origem de células homozigotas para os marcadores nutricionais: riboA1, pabaA124, biA1, metA17 e piroA4. A solução, diluída em 1:40, 1:20 e 1:10, induziu alterações morfológicas e atraso no desenvolvimento dos conidióforos da linhagem UT448//UT196 e aumento nas freqüências de recombinação mitótica. Embora trabalhos anteriores relatem a atividade antimicrobiana da solução em estudo, nossos resultados evidenciam a citotoxicidade e o potencial recombinagênico dessa substância.

Somatic recombination in heterozygous diploid cells may be a promotional agent of neoplasms by inducing homozygosity of defective genes. Tumor suppressor genes may in this way be completely suppressed in recombinant cells. In this work, the genotoxic effects of detergent derived from the castor oil plant (Ricinus communis) in heterozygous diploid cells of Aspergillus nidulans are evaluated. Previous studies have evaluated the application of this substance in endodontic treatments as an irrigating solution. The recombinogenic potential of the compound has been studied through the production of homozygous cells for nutritional markers riboA1, pabaA124, biA1, methA17, and pyroA4. Detergent was diluted to 1:10, 1:20, and 1:40, and morphologic alterations, delay in conidiophore development, and mitotic recombination occurrence were reported for the three dilutions. Although past studies have demonstrated the antimicrobial action of the detergent under analysis, our results revealed its cytotoxic effects and recombinogenic potential.

O presente trabalho cita a ocorrência de Trichogloea requienii no litoral da Bahia, nordeste do Brasil. O gênero é caracterizado por apresentar calcificação moderada na região entre os filamentos assimiladores (córtex) e medula, células mães dos espermatângios dispostas em verticilos sobre as células subterminais corticais, carpogônio localizado no final do filamento assimilador e desenvolvimento de filamentos estéreis curtos nas células inferiores do ramo carpogonial. São apresentadas descrição e ilustração detalhadas do táxon, além da comparação com entidades afins. Esta é a primeira citação do gênero para o Atlântico Sul.

Trichogloea requienii was collected in Bahia (northeastern Brazil). The genus is recognized easily for presenting moderate calcification between assimilatory filaments (cortex) and medulla, spermatangia mother cells in whorls on subterminal cortical cells, carpogonial branch at the end of the assimilatory filaments and sterile filaments at the lower cells of the carpogonial branch. Description and detailed illustrations of the taxon are presented as well as comparation with related species. This is the first citation of this genus to the South Atlantic.