RESUMO: A melancia é uma das olerícolas mais importantes do Brasil, situando o país entre os maiores produtores mundiais. Os vírus se destacam como agentes de doenças prejudiciais, que podem reduzir drasticamente a produção de frutos. Plantas daninhas presentes em campos cultivados também podem interferir na produção de hortaliças, atuando como reservatórios de vírus. O presente estudo teve como objetivo determinar a ocorrência de vírus em plantas daninhas nas principais regiões produtoras de melancia do estado de Tocantins. A identificação de vírus (em geral: os potyvírus Watermelon mosaic virus - WMV, Papaya ringspot virus - type watermelon - PRSV-W, e Zucchini yellow mosaic virus - ZYMV; o cucumovírus Cucumber mosaic virus - CMV e o orthotospovírus Zucchini lethal chlorosis virus - ZLCV) foi realizada por meio de testes serológicos e confirmada por RT-PCR. Os resultados sorológicos e moleculares indicaram que as espécies Amaranthus spinosus, Nicandra physaloides, Physalis angulata e Heliotropium indicum estavam infectadas com pelo menos uma espécie viral. A maior taxa de infecção foi representada por ZYMV (52,7%), seguido por PRSV-W (22,2%), CMV, WMV e ZLCV com a mesma taxa de infecção (8,3%). A espécie Physalis angulata, na qual foram detectadas todas as cinco espécies virais, representou 50% do total de plantas infectadas. As maiores porcentagens de infecção viral em plantas daninhas, 50% e 44,4% foram encontradas em amostras coletadas em Lagoa da Confusão e Formoso do Araguaia, respectivamente. Os resultados de ocorrência e distribuição de vírus infectando plantas daninhas em áreas cultivadas com melancia no estado de Tocantins geram informações importantes sobre o papel destas plantas como reservatórios de vírus em campos cultivados com melancia, bem como contribui para o conhecimento da epidemiologia dessas doenças de modo a propiciar o manejo adequado de plantas daninhas e a disseminação secundária desses vírus por meio de insetos vetores.

ABSTRACT: Watermelon is one of the most important vegetable crops in Brazil, which is grouped among the greatest producers worldwide. Viruses stand out among the most damaging disease agents, which can drastically reduce fruit production. In this context, weeds present in the field can also interfere in crop production, acting as reservoirs for viruses. Thus, this study aimed to investigate virus occurrence in weeds at the main watermelon-growing regions in the State of Tocantins. Viruses identification (e.g. potyviruses: Watermelon mosaic virus - WMV; Papaya ring spot virus - type watermelon -PRSV-W; Zucchini yellow mosaic virus- ZYMV; the cucumovirus Cucumber mosaic virus - CMV, and the orthotospovirus Zucchini lethal chlorosis virus - ZLCV) infecting weeds was performed by serology and confirmed by RT-PCR tests. Serological and molecular test results indicate that Amaranthus spinosus, Nicandra physaloides, Physalis angulata and Heliotropium indicum were infected by at least one virus species. The highest infection rate was represented by ZYMV (52.7%), followed by PRSV-W (22.2%); CMV, WMV, and ZLCV that showed the same infection rate (8.3%) each. Plants of P. angulata were infected by all five viruses, singly or in mixed infection, and represented 50% of the total number of infected samples. The highest virus infection rates, 50% and 44.4%, occurred in weeds collected at Lagoa da Confusão and Formoso do Araguaia, respectively. The results on occurrence and distribution of viruses infecting weeds in watermelon commercial plantations in the State of Tocantins provide important information about the role of weeds as virus reservoirs contribute to the knowledge of the epidemiology of these diseases, and enable a proper weed management aiming at reducing the secondary spreading control of viruses by insect vectors.

RESUMO O objetivo deste estudo foi determinar os valores energéticos de rações expandidas, obtidas em diferentes temperaturas de expansão para frangos de corte em diferentes idades. As rações foram expandidas nas temperaturas: 80; 100; 120; 140ºC. Dois ensaios biológicos foram conduzidos utilizando-se o método tradicional de coleta total de excretas para determinar a energia metabolizável aparente corrigida (EMAn). Os ensaios metabólicos foram conduzidos com pintos machos Cobb, de 11 a 19 dias (fase inicial) e de 27 a 35 dias de idade (fase de crescimento), utilizando-se as mesmas aves do primeiro ensaio e, assim, preservando os tratamentos a que foram submetidas. Os valores da EMAn das rações da fase inicial foram: 2937; 2900; 2806 e 2751kcal/kg, e da fase de crescimento: 3045; 3031; 3115 e 2977kcal/kg, respectivamente. Os resultados mostraram uma redução linear dos níveis de EMn com o aumento da temperatura de expansão na idade de 11 a 19 dias. As perdas relativas entre as rações expandidas a 80 e 100ºC foram mínimas, enquanto nas temperaturas de 120 e 140ºC foram significativamente superiores. No ensaio de metabolismo para a fase de crescimento, verificou-se que as perdas relativas entre as rações expandidas a 80 e 100ºC foram pequenas (-14kcal). Para a ração expandida a 120ºC, o valor energético foi superior (84 kcal), enquanto para 140ºC foi significativamente inferior (-138kcal). Esses resultados mostram que, na fase de crescimento, os frangos de corte maximizaram o aproveitamento energético das rações na temperatura de expansão de 120ºC e que, em temperaturas acima desse nível, ocorrem altas perdas da EMAn das rações, que podem comprometer o consumo, a deposição de proteína e a conversão alimentar e, consequentemente, trazer grandes prejuízos econômicos pelo menos à idade de abate. As temperaturas de expansão de rações entre 80 e 100ºC apresentaram os melhores valores de EMAn para frangos com idade entre 15 e 10 dias, enquanto para idade de 31 a 35 dias foi de 120ºC.

ABSTRACT The aim of this study was to determine the energetic value of feed in different expansion temperatures for broilers of different ages. The feedexpanded in the following temperatures: 80; 100, 120 and 140ºC. Two biological assays were run to establish apparent metabolizable energy corrected by nitrogen balance (AMEN) using the traditional total excreta collection method. In the first assay Cobb chicks were used from 11 to 19 days of age (initial period), and 29 to 37 days of age (growth period), as well as the same treatments of the first assay. The AMEN values for the initial period were respectively: 2937, 2900, 2806 and 2751 kcal/kg; and broilers in growing period were respectively: 3045, 3031, 3115 and 2977 kcal/kg. The results showed a linear decrease of the levels EMAN with an increase of the temperature of expansion from 11 to 19 days old. The loss relation between feed expanded at 80 and 100ºC were minimal, while in temperatures between 120 and 140ºC they were significantly higher. In the metabolic assay for period growth, we observed that the relation of energy values between feed expanded at 80 and 100ºC were smaller (14 kcal), while for the expanded in 120ºC they were superior (84 kcal), and at 140ºC were inferior (138 kcal). These results suggest greater energy utilization efficiency in period growth at a temperature of 120 ºC, while in temperatures above of this level there was greater loss of EMAN in feeds, which can prejudice feed intake, protein deposition and feed conversion, and consequently damage economics by increasing slaughter age. The expansion temperatures in feed between 80 and 100ºC showed the best EMAN values for broilers with 15 - 19 days of age, while for 31 - 35 days old it was 120 ºC.

The current study was conducted to investigate the relationship between melatonin and chronic anovulation. Adult (3-4 months old) female Wistar rats were submitted to pinealectomy: group I: pinealectomized ovariectomized melatonin-treated (N = 10); group II: pinealectomized ovariectomized placebo-treated (N = 12); group III: pinealectomized light-treated placebo-treated(N = 10) or maintained under continuous light; group IV: maintained under continuous light, ovariectomized melatonin-treated (N = 22); group V: maintained under continuous light, ovariectomized placebo-treated (N = 10); group VI: maintained under continuous light placebo-treated (N = 10). In order to assess ovarian modifications, unilateral ovariectomy was performed during the fourth month in groups I, II, IV, V and the other ovary was removed after 8 months. Ovariectomy was performed in groups III and VI only after eight months. Melatonin (200 µg/100 g body weight) dissolved in 0.02 ml absolute ethanol was injected intramuscularly daily during the last 4 months into groups I and IV. The other groups were treated with placebo (NaCl). The ovarian cysts were analyzed and their area, perimeter and maximum diameter, as well as the thickness of the ovarian capsule were measured. Daily colpocytological smears were performed throughout the study. Persistent estrous condition and ovarian cysts were observed in all groups. In pinealectomized rats the ovarian and vaginal alterations disappeared at the end of the study and in rats maintained under continuous light the vaginal and ovarian polycystic aspect was reversed only in those treated with melatonin. We conclude that melatonin may act on the ovarian response reverting chronic anovulation induced by pinealectomy or continuous light.