The objective of this study was to examine the endothelial surface morphology and to perform morphometric analysis of the corneal endothelial cells of Yacare caiman (Caiman yacare) using scanning electron microscopy. Morphometric analysis with regard to polygonality, mean cell area, cell density and coefficient of variation of mean cell area was performed. Cell areas were measured using image analysis software. The normal corneal endothelium of Yacare caiman consisted of polygonal cells of uniform size and shape with interdigitations of the cell borders. Microvilli appeared as protrusions on the cellular surface. The average cell area was 270 +/- 24 microm(2) and the endothelial cell density was 3704 +/- 324 cells/mm(2). The coefficient of variation of cell area was 0.22. This study demonstrates that the Yacare caiman corneal endothelium is similar to those described in other vertebrates.

Xylella fastidiosa causes citrus variegated chlorosis (CVC). Information generated from the X. fastidiosa genome project is being used to study the underlying mechanisms responsible for pathogenicity. However, the lack of an experimental host other than citrus to study plant-X. fastidiosa interaction has been an obstacle to accelerated progress in this area. We present here results of three experiments that demonstrated that tobacco could be an important experimental host for X. fastidiosa. All tobacco plants inoculated with a citrus strain of X. fastidiosa expressed unequivocal symptoms, consisting of orange leaf lesions, approximately 2 months after injection of the pathogen. CVC symptoms were observed in citrus 3 to 6 months after inoculation. The pathogen was readily detected in symptomatic tobacco plants by polymerase chain reaction (PCR) and phase contrast microscopy. In addition, X. fastidiosa was reisolated on agar plates in 4 of 10 plants. Scanning electron microscopy analysis of cross sections of stems and petioles revealed the presence of rod shaped bacteria restricted to the xylem of inoculated plants. The cell size was within the limit typical of X. fastidiosa.

The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates.

No abstract

A lesion nematode population infecting citrus in the state of Sao Paulo, Brazil is described and named Pratylenchus jaehni sp. n. Biological, molecular and morphological characteristics of this new species are compared with those of the morphologically similar P. coffeae and P. loosi. Results of mating experiments showed that P. jaehni is reproductively isolated from P. coffeae. Molecular (D2/D3 DNA sequences) dissimilarities among P. jaehni sp. n., P. coffeae and P. loosi were documented in a previous study. The morphology of seven P. coffeae populations from tropical America and eastern Java and a P. loosi population from Sri Lanka is used for comparison with the morphology of P. jaehni sp. n. Pratylenchus jaehni differs from P. coffeae and P. loosi by only a few morphological characters of the females. The mean values of stylet length, stylet knob height, and vulva position are smaller (< 15 vs > 15 ¹m, < 2.7 vs > 2.7 ¹m, < 79 vs > 79%) than those in P. coffeae and P. loosi. The tail terminus is usually subhemispherical and smooth in P. jaehni sp. n., whereas it is commonly truncate and indented in most P. coffeae populations and bluntly or nely pointed in P. loosi. Because of the morphological similarities among P. jaehni sp. n., P. coffeae and P. loosi, examination of at least ten specimens is required to obtain a reliable diagnosis based on morphology. Nineteen morphometric parameters for P. jaehni sp. n. and P. coffeae ranged from 0-13% smaller in xed than in live specimens.

The aim of this study was to examine the endothelial surface morphology and perform a morphometric analysis of the corneal endothelial cells of ostrich (Struthio

RESUMOPalavras-chave adicionais: Brachiaria brizantha, Panicum maximum, patógeno.Objetivou-se avaliar a incidência de fungos e nematoides em sementes de Brachiaria sp. e Panicum maximum produzidas nos estados de Mato Grosso do Sul (MS), Mato Grosso (MT), Goiás (GO), Minas Gerais (MG) e São Paulo (SP Com a expansão das pastagens e intensificação da atividade pecuária nos últimos anos, várias doenças de forrageiras começaram a ter importância significativa, especialmente nas regiões centro-oeste e norte do Brasil, causando perdas em produtividade e qualidade de pastagens.Pouco se conhece sobre a qualidade sanitária de sementes forrageiras produzidas e comercializadas no país, o que provavelmente contribui para o aumento da incidência de doenças em áreas de pastagens (6).A associação de patógenos às sementes representa impacto significativo no estande, desenvolvimento das plantas, produção de sementes, persistência das forrageiras no campo e, consequentemente, na produção de leite e carne. Além disso, a presença de patógenos nas sementes constitui entrave para a exportação de sementes (2, 3).Amostras de lotes comerciais de sementes de cultivares Brachiaria sp. e Panicum maximum da safra 2009/2010 e produzidas em diferentes regiões produtoras do país foram analisadas quanto à This study aimed to assess the incidence of fungi and nematodes in Bra c h ia ria sp. a nd Pa n ic u m ma x imu m seeds produ ced in the Brazilia n sta tes of Ma to Grosso do Sul (MS), Ma to Grosso (MT ), Goiás (GO), Minas Gerais (MG) and São Paulo (SP). The main fungi found in the seeds were Bipolaris sp., Curvularia sp. and Phoma sp.. The lowest incidence of these fungi was found for seeds of Brachiaria brizantha cultivars BRS Piatã and Xaraés, and Brachiaria decumbens cv. Basilisk, from the states of GO, MG and MS, respectively ABSTRACTB. humidicola cultivar Humidicola, produced in MS and SP, did not show a ssociation with nematodes. T he seeds of Pa nic um ma ximum cv. Massai a nd cv. Mombaça showed higher incidence of Bipolaris sp., Cladosporium sp., Curvularia sp., Fusarium sp. and Phoma sp., as well as Ap he le nc ho id es sp. a nd Dity le nc hu s sp., especially for seeds produced in MT. Some of the detected pathogens are causative a gents of disea ses of ma jor importa nce in fora ge pla nts, such a s Bip o la ris sp., ca u sing lea f spot in Pa n ic u m, of high severity in Ta nzâ nia , which provides seriou s compromising of the pa stu re sustainability.

Endothelial cell function is essential to maintain corneal transparency, but unfortunately the regenerative capacity of the endothelium is limited. There are only a few reports describing the effect of age on morphologic appearance of corneal endothelial cells of dogs. Studies of normal corneal endothelial cells in humans and dogs have shown a decrease in endothelial cell density (ECD) and an increase in pleomorphism and polymegethism with advancing age. The purpose of this study was to investigate the effect of age on ECD and endothelial cell morphology in dogs. A total of 30 dogs were divided into three groups (10 dogs/group) based on age: group 1 (2-12 months old), group 2 (24-72 months old), and group 3 (84 months or older). Corneas were processed for light and scanning electron microscopy. Results showed only difference in cell density between group 1 and groups 2 and 3, showing an initial decrease in cell density as the animal matured. Whereas there was significantly greater variation in cell size within the dogs in group 3 than there was within the other two groups, suggesting that there was increased polymegethism and pleomorphism with advancing age.