40 research outputs found
Efeito do espacamento sobre o crescimento e producao de porta-enxertos de seringueira.
O trabalho foi conduzido com o objetivo de se determinar, para as condicoes edafoclimaticas de Manaus, qual espacamento entre plantas seria mais viavel tecnica e economicamente para a producao de porta-enxertos de seringueira (Hevea sp.). Foram testados doze tratamentos, constituidos por doze diferentres arranjos de espacamento entre linhas e entre plantas nas linhas. Constatou-se que, para a producao de mudas de seringueira do tipo toco-enxerto de raiz nua, empregando o metodo de enxertia verde, o melhor espacamento de viveiro para a producao dos porta-enxertos, tecnica e economicamente, e o de 60 cm x 15 cm. E para a producao do mesmo tipo de muda, empregando o metodo de enxertia convencional, o melhor espacamento e o de 70 cm x 15 cm, seguido pelo de 60 cm x 15 cm
Evidence that the Ceratobasidium-like white-thread blight and black rot fungal pathogens from persimmon and tea crops in the Brazilian Atlantic Forest agroecosystem are two distinct phylospecies
The white-thread blight and black rot (WTBR) caused by basidiomycetous fungi of the genus Ceratobasidium is emerging as an important plant disease in Brazil, particularly for crop species in the Ericales such as persimmon (Diospyros kaki) and tea (Camellia sinensis). However, the species identity of the fungal pathogen associated with either of these hosts is still unclear. In this work, we used sequence variation in the internal transcribed spacer regions, including the 5.8S coding region of rDNA (ITS-5.8S rDNA), to determine the phylogenetic placement of the local white-thread-blight-associated populations of Ceratobasidium sp. from persimmon and tea, in relation to Ceratobasidium species already described world-wide. The two sister populations of Ceratobasidium sp. from persimmon and tea in the Brazilian Atlantic Forest agroecosystem most likely represent distinct species within Ceratobasidium and are also distinct from C. noxium, the etiological agent of the first description of white-thread blight disease that was reported on coffee in India. The intraspecific variation for the two Ceratobasidium sp. populations was also analyzed using three mitochondrial genes (ATP6, nad1 and nad2). As reported for other fungi, variation in nuclear and mitochondrial DNA was incongruent. Despite distinct variability in the ITS-rDNA region these two populations shared similar mitochondrial DNA haplotypes
Efficacy and safety of atazanavir-ritonavir plus abacavir-lamivudine or tenofovir-emtricitabine in patients with hyperlipidaemia switched from a stable protease inhibitor-based regimen including one thymidine analogue.
Randomized, open-label, prospective clinical trial assessing efficacy and safety on hyperlipidemia of a switching from a regimen including one protease inhibitor and one thymidine analogue to atazanavir/ritonavir plus abacavir/lamivudine or tenofovir/emtricitabine. Adult HIV-infected patients on their first antiretroviral therapy (of at least 48-week duration), including one protease inhibitor and zidovudine or stavudine, with stable immunovirologic features, and having diagnosis of persisting hyperlipidemia, were randomized to replace current treatment with atazanavir/ritonavir plus abacavir/lamivudine (arm A) or tenofovir/emtricitabine (arm B), and were followed for 48 weeks. Eighty-nine patients were enrolled: 42 patients were randomized to arm A, and 47 to arm B. At the end of the 48-week follow-up, incidence of virologic failure was comparable in both arms, and associated with a poor drug compliance. Increase in CD4 lymphocyte count was significantly higher in arm A after a 24-week study period (62.5 versus 39.2 x 10(6) cells/L; p < 0.05), while immunologic responses were comparable at the end of 48-week follow-up (91.5 versus 83.6; p > 0.05). A statistically significant reduction (-15.4%) in mean triglyceridaemia versus respective baseline values was reported in both groups (p < 0.05), without statistically significant difference between arm A and B. Similar results were reported for total cholesterol and low-density lipoprotein (LDL) cholesterol levels. Safety and tolerability profiles were comparable in both groups. Switching from a protease inhibitor- and thymidine analogue-based antiretroviral regimen to atazanavir/ritonavir plus abacavir/lamivudine or tenofovir/emtricitabine proved effective in the management of hyperlipidemia, without significant differences in lipid-lowering effect, virologic efficacy, and safety profile between these regimens
Patogenicidade cruzada de Ceratobasidium spp. do caquizeiro (Diospyros kaki) e do chá(Camellia sinensis) e reação de cultivares de caqui ao patógeno Cross pathogenicity of Ceratobasidium spp. from kaki (Diospyros kaki) and tea (Camellia sinensis) and reaction of kaki varieties to the pathogen
O fungo Ceratobasidium spp. é o agente causal da doença mal-do-fio ou queima-do-fio em várias plantas frutíferas, em cafeeiro e em chá. Esta doença ocorre com maior freqüência em zonas de alta precipitação e temperaturas elevadas, típicas de regiões de florestas tropicais como a Amazônica e a Mata Atlântica. Em São Paulo, o primeiro relato do mal-do-fio em caquizeiro ocorreu na região de Mogi das Cruzes. O objetivo deste estudo foi testar a patogenicidade cruzada de isolados de Ceratobasidium spp. de caquizeiro e chá para ambas as culturas e também para o cafeeiro e citros. Avaliou-se, também, a reação de oito cultivares de caquizeiro, sob condições controladas, a isolados de Ceratobasidium spp. obtidos da mesma cultura. Constatou-se que os isolados de caquizeiro e de chá, embora filogeneticamente distintos, foram patogênicos para ambas as culturas, além de afetarem cafeeiro e citros. Não foram verificados indícios de reação de resistência aos isolados de Ceratobasidium spp. para as oito cultivares de caquizeiro testadas.<br>The fungus Ceratobasidium spp. causes the white-thread blight disease, which affects several fruit trees, coffee and tea crops. This disease frequently occurs in zones of high precipitation and temperatures, typical of the tropical forest regions such as the Amazon and the Atlantic Forests. In São Paulo State, Brazil, this disease was reported by the first time affecting kaki plants in Mogi das Cruzes county. The objective of this study was to test the cross-pathogenicity of Ceratobasidium spp. isolates from kaki and tea to both host plants and also to coffee and citrus. This study also aimed to determine the reaction of local kaki varieties to Ceratobasidium spp. isolates from kaki under controlled conditions. Although phylogenetically distinct, kaki- and tea-infecting isolates were cross-pathogenic to both hosts, besides infecting coffee and citrus. There was no indication of resistance reaction among the eight kaki varieties tested