Centro de Ciências Agrárias

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11727

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Molecular mapping of the viral determinants of systemic wilting induced by a Lettuce mosaic virus (LMV) isolate in some lettuce cultivars
(Virus Research, 2005-05) Zerbini, F. Murilo; Krause-Sakate, Renate; Redondo, Elise; Richard-Forget, Florence; Jadão, Adriana Salomão; German-Retana, Sylvie; Pavan, Marcelo Agenor; Candresse, Thierry; Gall, Olivier Le; Houvenaghel, Marie Christine
The isolate AF199 of Lettuce mosaic virus (LMV, genus Potyvirus) causes local lesions followed by systemic wilting and plant death in the lettuce cultivars Ithaca and Vanguard 75. Analysis of the phenotype of virus chimeras revealed that a region within the P1 protein coding region (nucleotides 112–386 in the viral genome) and/or another one within the CI protein coding region (nucleotides 5496–5855) are sufficient together to cause the lethal wilting in Ithaca, but not in Vanguard 75. This indicates that the determinants of this particular symptom are different in these two lettuce cultivars. The wilting phenotype was not directly correlated with differences in the deduced amino acid sequence of these two regions. Furthermore, transient expression of the LMV-AF199 proteins, separately or in combination, did not induce local necrosis or any other visible reaction in the plants. Together, these results suggest that the systemic wilting reaction might be due to RNA rather than protein sequences.
Pre-harvest calcium sulfate applications affect vase life and severity of gray mold in cut roses
(Scientia Horticulturae, 2005-01-30) Maffia, Luiz A.; Finger, Fernando L.; Batista, Ulisses G.; De Capdeville, Guy
Gray mold, caused by Botrytis cinerea Pers. Fr., is a major disease in roses. The effect of spraying rose (Cultivar ‘Kiss’) buds with calcium sulfate on the intensity of gray mold was evaluated. Calcium sulfate was sprayed on the buds at different schedules and concentrations before harvest. Thereafter, the buds were harvested and either inoculated or not with B. cinerea. The treatments reduced both the progress and severity of gray mold and increased vase life of the flowers. Good results were achieved with 10 and 20 mM calcium sulfate, applied 24 h before harvest. In the uninoculated assay, the maximum percentages of reduction of the area under the disease progress curve (AUDPC) and of severity were 86% and 86%, respectively, and in the inoculated assay, 68% and 76%, respectively. Vase life of the flowers was increased at least 30% in the assay without inoculation and 20% in the assay with inoculation. Spraying roses with calcium sulfate at 10 mM or 20 mM one day before harvest is recommended to control gray mold after harvest.
Validation of the 9–11th rib cut to estimate the chemical composition of the dressed carcass and of the whole empty body of Zebu cattle
(Livestock Production Science, 2005-05) Paulino, Pedro Veiga Rodrigues; Valadares Filho, Sebastião de Campos; Costa, Marcos Antônio Lana; Paulino, Mário Fonseca; Magalhães, Karla Alves; Detmann, Edenio; Valadares, Rilene Ferreira Diniz; Porto, Marlos Oliveira; Andreatta, Kamila
This study was conducted to validate the 9–11th rib cut to estimate the chemical composition of the carcass and of the empty body weight (EBW) of Zebu cattle. Nineteen Zebu steers with initial body weight of 266.5±32.2 kg were used. Four steers were slaughtered at the beginning to compose the reference group; three were fed at maintenance level, and the remaining were allotted to different planes of nutrition (5.0%, 35.0% and 65.0% concentrate levels in the diets, DM basis). The 9–11th rib cuts and half of the carcasses were dissected and the weights of fat, muscle and bone tissue were recorded. The components fat, muscle and bone tissue from the 9–11th rib cut and from the half carcass were sampled and chemical analysis of fat, protein, water, ash and minerals determined. The 9–11th rib cut satisfactorily estimated the physical composition of the carcass, but not the chemical composition. The 9–11th rib cut appropriately estimated the chemical composition of the carcass in terms of protein, water, ash and macro mineral content. For the percentage of fat and Ca, an over- and underestimation of 7.84% and 13.34%, respectively, were detected. Regression equations were fitted to estimate the percentage of fat and Ca in the carcass, and that of protein, water and ash in the whole empty body.