116 research outputs found
Somatic embryogenesis and in vitro plant regeneration from pejibaye adult plant leaf primordia
O objetivo deste trabalho foi avaliar um protocolo de regeneração de plantas por meio de embriões somáticos, obtidos a partir de primórdios foliares de pupunheiras adultas e identificar a origem histológica dos embriões e descrever as etapas morfogenéticas. Os explantes foram cultivados em meio MS modificado. Células parenquimáticas do mesofilo originaram meristemóides com BAP (7,1 µM) nos dois primeiros períodos de subcultura. A polarização das estruturas ocorreu com ANA (12,9 µM) e BAP (3,55 µM) no terceiro período de subcultura. Meristemóides se desenvolveram em embriões somáticos, regenerando plantas normais. As células parenquimáticas do mesofilo apresentam elevada capacidade de resposta direta à auxina e à citocinina.The aim of this work was to evaluate a protocol for plant regeneration by means of somatic embryos obtained from isolated adult pejibaye leaf primordia, and to describe histological origin of embryos and morphogenetic response. Explants were cultivated in modified MS medium. Mesophyll parenchymatous cells originated meristemoids (preembryonic complex formation) induced with 7.1 µM BAP in the first two subculture periods. After polarized structures with 12.9 µM NAA and 3.55 µM BAP were formed in the third subculture, somatic embryos developed and regenerated normal plants. The mesophyll parenchymatous cells display high capacity of direct response to the auxin and cytokinin
Ecological anatomy of Eugenia glazioviana Kiaersk leaf (Myrtaceae)
Dos mecanismos com potencial valor adaptativo em resposta ao estresse hídrico merece destaque o apresentado por Eugenia glazioviana Kiaersk cuja perda de turgescência foliar e consequente curvatura do limbo da posição horizontal para a vertical, sem a abscisão das folhas, que estão associados à redução da superfície foliar exposta à luz solar. Dessa forma, o presente trabalho teve por objetivo a caracterização histológica da folha da espécie, visando compreender melhor esse mecanismo de resposta ao estresse hídrico. Para tanto foram realizados cortes transversais e paradérmicos da lâmina foliar, bem como, cortes transversais do pecíolo, sendo estes analisados e as imagens capturadas em microscópio de luz. Os resultados permitem, entre outras coisas, afirmar que E. glazioviania possui características tipicamente xerofíticas, sendo elas: cutícula espessa em ambas as superfícies, folha hipoestomática, com muitos tricomas tectores na face abaxial, além de uma característica que pode ser exclusiva da espécie e que possivelmente justifique tal resposta, a qual relaciona-se a presença de ductos glandulares, que percorrem toda a extensão do pecíolo, em continuidade com a lâmina foliar.In response to hydrous stress, the adaptive mechanisms with a potential adaptive value presented by Eugenia glazioviana Kiaersk is notable, whose leaf turgidity loss and the blade consequent curvature from the horizontal to vertical position, without the leaves abscission, are associated with the reduction of the leaf surface exposed to sunlight. This study aimed to characterize histological leaf species to better understand the mechanism in response to hidrous stress. Therefore, we performed transverse and paradermal cuts from the leaf blade and petiole cross-sections. They were analyzed and the images were captured under light microscope. Among other things, the results allowed to state that E. glazioviana has typically xerophytic characteristics, namely: thick cuticle on both surfaces, hypostomatic leaves with many trichomes on the abaxial side, and a characteristic that may be unique to that species and possibly justify such response, which is related to the glandular ducts presence, running the petiole length in continuity with the leaf blade
Somatic embryogenesis and in vitro plant regeneration from pejibaye adult plant leaf primordia
In vitro multiplication of Eucalyptus grandis under BAP pulse
O objetivo deste trabalho foi avaliar os efeitos do estímulo com benzilaminopurina (BAP) na multiplicação in vitro de Eucalyptus grandis. Foram avaliadas as interações entre concentrações de BAP (0, 200, 400 e 600 mg L-1), tempo de exposição (1, 2 e 3 horas), pH (3 e 5,8) da solução e alterações morfológicas dos explantes. Semanalmente, foi determinada a massa da matéria fresca dos explantes. Aos 21 dias de cultura, foram avaliados: o número de brotações por tratamento, o número de brotações obtidas por explante (taxa de multiplicação), e foi realizado o resgate das plântulas para avaliação histológica. O pH não apresentou interação com os demais fatores estudados. Os tratamentos com BAP a 200 mg L-1, durante 1 e 2 horas, apresentaram-se como os mais indicados na multiplicação do E. grandis. Houve intensificação da divisão celular, no parênquima cortical e no procâmbio, representada pelo surgimento de meristemóides, em resposta aos tratamentos com 200 mg L-1 de BAP, durante 1 e 2 horas. O estímulo com BAP na multiplicação in vitro de E. grandis é viável.The objective of this work was to evaluate the effect of pulse on in vitro multiplication of Eucalyptus grandis. Interactions were evaluated among BAP concentrations (0, 200, 400 and 600 mg L-1), exposure time (1, 2 and 3 hours), pH values (3 and 5.8), and explant morphological changes. Fresh weight of the explants was determined weekly. At 21 days of culture, valuations were made of the number of shootings per treatment, number of shootings obtained per explant (multiplication rate), and seedlings rescue was accomplished for histological analysis. The pH values did not present any interaction with the other factors. The most significant treatments on E. grandis shoot multiplications were 200 mg L-1 of 6-BAP during 1 and 2 hours. There was an intensification of cell division in the cortical parenchyma and procambium, represented by the arising of meristems in response to 200 mg L-1 of BAP treatment, during 1 and 2 hours. The use of the pulse on in vitro multiplication of E. grandis is feasible
Decreased fertility in poor responder women is not related to oocyte morphological status
Introduction: In women showing impaired fertility, a decreased response to ovarian stimulation is a major problem, limiting the number of oocytes to be used for assisted reproduction techniques (ART). Despite the several definitions of poor response, it is still a matter of debate whether young poor responder patients also show a decrease in oocyte quality. The objective in this study was to investigate whether poor ovarian response to the superstimulation protocol is accompanied by impaired oocyte quality. Material and methods: This study included 313 patients younger than 35 years old, undergoing intracytoplasmic sperm injection. Patients with four or fewer MII oocytes (poor-responder group, PR, n = 57) were age-matched with normoresponder patients (NR, n = 256). Results: A higher rate of oocyte retrieval and a trend towards an increase in MII oocyte rate were observed in the NR group when compared to the PR group (71.6 +/- 1.1% and 74.1 +/- 1.0% vs. 56.3 +/- 2.9% and 66.5 +/- 3.7%; p < 0.0001 and p = 0.056, respectively). A trend toward increased implantation rates was observed in the NR group when compared to the PR group (44 and 24.5 +/- 2.0% vs. 28.8 and 16.4 +/- 3.9%; p = 0.0305 and p = 0.0651, respectively). Conclusions: Low response to ovarian stimulation is apparently not related to impaired oocyte quality. However, embryos produced from poor responder oocytes show impaired capacity to implant and to carry a pregnancy to term
Lonomia obliqua Walker, 1855 (Lepidoptera: Saturniidae): first report in the Zona da Mata Mineira region, Southeast Brazil
Lonomia accidents occur by contact to caterpillar bristles that penetrate the skin of the victim. This moth presents toxins in its larval stage, which has hemorrhagic effects that can cause accidents and even death in humans. This study presents the first report of Lonomia obliqua in the Zona da Mata Mineira, Southeast Brazil. As the species abundance and phenology are still little known in the region further studies are important, so that prevention and educational measures can be adopted
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