Inbreeding depression in single, three way and double-cross hybrids of maize.

Currently, one of the acclaimed alternatives for increasing maize yield is accomplished through utilization of heterosis in hybrid cultivars. However, upon performing crosses between related pairs, there are losses due to inbreeding depression. Thus, the aim of this study was to estimate inbreeding depression and the contribution of loci in heterozygosity in different types of maize hybrids. Eight treatments were evaluated, considering the F1 and S0 generations of four commercial hybrids. A randomized block experimental design was used, with three replications, and plots consisting of two three-meter long rows at a spacing of 0.50 m. The traits evaluated were plant height, first ear height and husked ear weight. For ear weight trait, there was a significant difference, where the treatments could be classified into three distinct groups. In this case, the single-cross hybrids AG7088 and 30F90Y exhibited greater depression through inbreeding due to the greater contribution of loci in heterozygosity and consequent predominance of deviations due to dominance.

Indirect selection of industrial tomato genotypes rich in zingiberene and resistant to Tuta absoluta Meyrick.

Obtaining tomato cultivars resistant to pests through interspecific crosses between commercial cultivars and wild accessions is an important tool in integrated pest management. The aim of this study was to select tomato genotypes with high zingiberene (ZGB) levels that are resistant to the South American tomato moth (Tuta absoluta Meyrick) and to estimate genetic parameters of ZGB inheritance from the interspecific cross Solanum lycopersicum cultivar 'Redenção' x Solanum habrochaites var. hirsutum (PI-127826 accession). F2 plants with different ZGB contents were selected and submitted to a tomato moth resistance test. ZGB content exhibits high broad sense heritability, with incomplete dominance of lower ZGB content. Furthermore, the level of ZGB in leaflets was estimated to be controlled by two genes. These results show that high ZGB levels are effective at conferring resistance to the South American tomato moth.

Selection of processing tomato genotypes with high acyl sugar content that are resistant to the tomato pinworm.

Acyl sugars are allelochemicals present at high concentrations in leaves of accessions of the wild tomato Solanum pennellii; they confer resistance to a large number of arthropod pests, including the tomato pinworm, Tuta absoluta (Lepidoptera, Gelechiidae). Accession 'LA716', with high contents of acyl sugars in the leaves, was used as a source of resistance to start a genetic breeding program of processing cultivated tomato, S. lycopersicum. We selected plants of the F2 generation of an interspecific cross (S. lycopersicum cv. 'Redenção' x S. pennellii 'LA716') for extremes of concentrations (high and low) of acyl sugars in the leaves and evaluated the resistance of selected genotypes to the tomato pinworm, compared with plants of the parental and F1 generations. The concentrations of acyl sugars present in the genotypes selected for high contents were close to those of S. pennellii 'LA 716', while the genotypes with low concentrations of acyl sugars were close to cultivar 'Redenção'. The F1 hybrid ('Redenção' x 'LA716') had intermediate concentrations of acyl sugars, but was closer to Redenção, indicating that the inheritance of this type of character is due to a recessive major gene, along with minor genes with additive effects. There was a direct association between high contents of acyl sugars and non-preference for oviposition and suppression of larval development, indicating that the allelochemical acts through mechanisms of non-preference for oviposition and through antibiosis. Genotypes with high contents of acyl sugars were more effective in reducing the damage caused by the tomato pinworm. Genotypes RVTA-2010pl#94 and RVTA-2010pl#31, selected for high contents of acyl sugars, showed a good level of resistance to T. absoluta, similar to the wild genotype LA716. These genotypes are promising for use in a breeding program for developing commercial processing tomatoes.

Ectoparasitic flies (Diptera, Streblidae) of bats (Chiroptera, Phyllostomidae) in an Atlantic Forest area, southeastern Brazil.

We studied infestation rates and parasite-host associations between streblid flies and phyllostomid bats in an Atlantic Forest area of Rio de Janeiro state, southeastern Brazil. We captured 301 individuals from seven Phyllostomidae bat species. Out of that total, 69 bats had been parasitised by nine Streblidae species; the most frequent species were Trichobius joblingi and Trichobius tiptoni. The species Paraeuctenodes longipes, associated with Anoura geoffroyi, was the most frequent species. The highest mean intensity was observed for Paraeuctenodes longipes, associated with A. geoffroyi, and Paratrichobius longicrus associated with Artibeus lituratus, both ectoparasite species with a mean intensity of five individuals per bat. Trichobius joblingi exhibited the highest mean abundance, which was over three on its host species. Streblid richness in the study area was similar to the richness found in other studies carried out in the Atlantic Forest. We observed that streblid richness in this biome depends more on inherent characteristics of each physiognomy and on the host-species than on the sampling effort.

O uso de fitoterápicos à base de aroeira como coadjuvante no tratamento da gengivite: Revisão Sistemática / The use of aroreira-based phytotherapics as a supporting tool in the treatment of gingivits: A systematic Review

RESUMO O fator mais importante na manutenção da saúde periodontal é o adequado controle do biofilme dentário. Face às dificuldades no controle mecânico por parte dos pacientes, métodos alternativos ou complementares têm sido utilizados como coadjuvantes químicos do controle do biofilme, auxiliando no tratamento da gengivite. Dentre esses métodos alternativos, destaca-se a fitoterapia, através da utilização de plantas medicinais. Dessa forma, esse estudo faz uma revisão sistemática tendo como objetivo a busca, na literatura atual, de estudos que comprovem a eficácia de produtos fitoterápicos à base de aroeira no controle do biofilme dental auxiliando no tratamento da gengivite. Foi realizada busca computadorizada nos indexadores MedLine, Lilacs, BBO e Scielo no período de Setembro a Outubro de 2014. Os descritores de pesquisa utilizados foram “biofilme”, “gengivite”, “aroeira”, “plantas medicinais” e “fitoterápicos”, bem como seus correspondentes em língua inglesa. Através dos descritores utilizados, foram encontrados 54 artigos. Após a aplicação dos critérios de inclusão e exclusão, chegou-se a 08 artigos: 05 revisões, 01 estudo clínico randomizado, 01 estudo experimental e 01 estudo observacional descritivo. De acordo com os estudos analisados, a aroeira apresentou atividades antifúngica e antimicrobiana eficazes, bem como potencial efeito de redução do índice de sangramento gengival, o que justifica seu uso no tratamento da gengivite.

ABSTRACT The most important factor to keep periodontal health is proper control of biofilm. Given the difficulties in the mechanical control by patients, alternative or complementary methods have been used as chemical supporting of biofilm control, helping the treatment of gingivitis. Among these alternatives, there is the phytotherapy, through the use of medicinal plants. Thus, this study it is a systematic review and aims to seek, in the current literature, researches proving the effectiveness of aroeira herbal products in the control of dental biofilm, assisting in the treatment of gingivitis. A computerized search was conducted in Medline, Lilacs, Scielo and BBO, from September to October of 2014. The search words used were “biofilm”, “gingivitis”, “aroeira”, “herbal medicines” and “phytotherapics” in Portuguese and English language. Through this method, 54 articles were found. After applying the inclusion and exclusion criteria, the research reached 08 items: 05 reviews, 01 randomized clinical trial, 01 experimental study and 01 descriptive observational study. According to the analyzed papers, the aroeira demonstrated effective antifungal and antimicrobial activities, as well as a potential reduction impact on gingival bleeding index, which would justify its use in the treatment of gingivitis.

Ectoparasitic flies (Diptera, Streblidae) of bats (Chiroptera, Phyllostomidae) in an Atlantic Forest area, southeastern Brazil / Moscas ectoparasitas (Diptera, Streblidae) de morcegos (Chiroptera, Phyllostomidae) numa área de Mata Atlântica, sudeste do Brasil

We studied infestation rates and parasite-host associations between streblid flies and phyllostomid bats in an Atlantic Forest area of Rio de Janeiro state, southeastern Brazil. We captured 301 individuals from seven Phyllostomidae bat species. Out of that total, 69 bats had been parasitised by nine Streblidae species; the most frequent species were Trichobius joblingi and Trichobius tiptoni. The species Paraeuctenodes longipes, associated with Anoura geoffroyi, was the most frequent species. The highest mean intensity was observed for Paraeuctenodes longipes, associated with A. geoffroyi, and Paratrichobius longicrus associated with Artibeus lituratus, both ectoparasite species with a mean intensity of five individuals per bat. Trichobius joblingi exhibited the highest mean abundance, which was over three on its host species. Streblid richness in the study area was similar to the richness found in other studies carried out in the Atlantic Forest. We observed that streblid richness in this biome depends more on inherent characteristics of each physiognomy and on the host-species than on the sampling effort.

Estudou-se as taxas de infestação e as associações parasita-hospedeiros de dípteros estreblídeos ectoparasitas de morcegos filostomídeos, em um fragmento de Mata Atlântica, no estado do Rio de Janeiro. Foram capturados 301 indivíduos de sete espécies de morcegos da família Phyllostomidae. Desse total, 69 morcegos encontravam-se parasitados com nove espécies de Streblidae, sendo Trichobius joblingi e Trichobius tiptoni as espécies mais freqüentes do total de estreblídeos coletados. Paraeuctenodes longipes, associada à Anoura geoffroyi foi a espécie mais prevalente. A maior intensidade média foi encontrada para Paraeuctenodes longipes, associada à A. geoffroyi e Paratrichobius longicrus associada à Artibeus lituratus, ambos com cinco ectoparasitas em média por morcego infestado. Trichobius joblingi apresentou a maior abundância média de infestação, que foi superior a três nas espécies de hospedeiros em que foi encontrada. A riqueza de estreblídeos da área de estudo é similar àquela obtida em outros estudos realizados na Mata Atlântica, e verificou-se que a riqueza de estreblídeos nesse bioma depende mais de outras características inerentes a cada fitofisionomia e à espécie hospedeira do que do esforço amostral de coleta.

Immunohistochemical characterization of the chick marginal retina.

The retina is a highly differentiated tissue with a complex layered structure that has been extensively characterized. However, most of the previous studies focused on the histology of the central retina while little is known about the cellular composition, organization and function of the marginal retina. Recent research has identified a subpopulation of multipotential progenitor cells in the marginal regions of the retina, closest to the ciliary body ("ciliary marginal zone"). These cells are capable of differentiation in response to an appropriate stimulus. Thus, it is possible that the structure and composition of the marginal retina are distinct from those of the central retina to accommodate the potential addition of newly formed neurons. To characterize the cellular profile of the chick marginal retina, we labeled it immunohistochemically for markers whose staining pattern is well established in the central retina: calbindin, calretinin, protein kinase C, and choline acetyltransferase. Calbindin was present at very low levels in the marginal retina putative photoreceptor layer. Calretinin-positive horizontal cells were also sparse close to the ciliary marginal zone. The bipolar cells in the marginal outer plexiform layer were positive for anti-protein kinase C antibodies, but the density of labeling was also decreased in relation to the central retina. In contrast, the marginal starburst cholinergic amacrine cell pattern was very similar to the central retina. From these data we conclude that the structure of the marginal retina is significantly different from that of the central retina. In particular, the expression of late retina markers in the marginal retina decreased in comparison to the central retina.

Intestinal barrier function and secretion in methotrexate-induced rat intestinal mucositis.

Chemotherapy-induced mucositis is an important dose-limiting and costly side effect for which there is no definitive prophylaxis or treatment. This is due in part to the lack of understanding of its pathophysiology and impact on intestinal function. The objectives of this study were to investigate the small intestine barrier function and electrolyte and water transport in an experimental model of methotrexate-induced mucositis, and to correlate these alterations with histological damage. Wistar rats were treated with methotrexate (1.5-3.5 mg/kg) for 3 days to induce mucositis. Intestinal permeability was measured by the urinary excretion rate of lactulose and mannitol following administration by gavage. Intestinal perfusion was performed in vivo for evaluation of water and electrolyte transports. Methotrexate-treated rats lost a significant amount of weight and presented a marked reduction in food intake. Methotrexate induced significant and dose-dependent villous atrophy and elongation of crypts in duodenum, jejunum, and ileum. Methotrexate also induced an increase in sodium and potassium secretion and an important reduction of the mucosa absorptive surface area, shown by the decrease in the mannitol excretion ratio. In conclusion, methotrexate caused major changes in small bowel function by disrupting intestinal permeability and inducing electrolyte secretion in parallel with substantial histological damage.

Immunohistochemical characterization of the chick marginal retina

The retina is a highly differentiated tissue with a complex layered structure that has been extensively characterized. However, most of the previous studies focused on the histology of the central retina while little is known about the cellular composition, organization and function of the marginal retina. Recent research has identified a subpopulation of multipotential progenitor cells in the marginal regions of the retina, closest to the ciliary body ("ciliary marginal zone"). These cells are capable of differentiation in response to an appropriate stimulus. Thus, it is possible that the structure and composition of the marginal retina are distinct from those of the central retina to accommodate the potential addition of newly formed neurons. To characterize the cellular profile of the chick marginal retina, we labeled it immunohistochemically for markers whose staining pattern is well established in the central retina: calbindin, calretinin, protein kinase C, and choline acetyltransferase. Calbindin was present at very low levels in the marginal retina putative photoreceptor layer. Calretinin-positive horizontal cells were also sparse close to the ciliary marginal zone. The bipolar cells in the marginal outer plexiform layer were positive for anti-protein kinase C antibodies, but the density of labeling was also decreased in relation to the central retina. In contrast, the marginal starburst cholinergic amacrine cell pattern was very similar to the central retina. From these data we conclude that the structure of the marginal retina is significantly different from that of the central retina. In particular, the expression of late retina markers in the marginal retina decreased in comparison to the central retina.