Brazilian germplasm of winter squash (Cucurbita moschata D.) displays vast genetic variability, allowing identification of promising genotypes for agro-morphological traits.

Winter squash fruits (Cucurbita moschata D.) are among the best sources of vitamin A precursors and constitute sources of bioactive components such as phenolic compounds and flavonoids. Approximately 70% of C. moschata seed oil is made up of unsaturated fatty acids, with high levels of monounsaturated fatty acids and components such as vitamin E and carotenoids, which represent a promising nutritional aspect in the production of this vegetable. C. moschata germplasm expresses high genetic variability, especially in Brazil. We assessed 91 C. moschata accessions, from different regions of Brazil, and maintained at the Federal University of Viçosa (UFV) Vegetable Germplasm Bank, to identify early-flowering accessions with high levels of carotenoids in the fruit pulp and high yields of seed and seed oil. Results showed that the accessions have high variability in the number and mass of seeds per fruit, number of accumulated degree-days for flowering, total carotenoid content, and fruit productivity, which allowed selection for considerable gains in these characteristics. Analysis of the correlation between these characteristics provided information that will assist in selection to improve this crop. Cluster analysis resulted in the formation of 16 groups, confirming the variability of the accessions. Per se analysis identified accessions BGH-6749, BGH-5639, and BGH-219 as those with the earliest flowering. Accessions BGH-5455A and BGH-5598A had the highest carotenoid content, with averages greater than 170.00 µg g-1 of fresh mass. With a productivity of 0.13 t ha-1, accessions BGH-5485A, BGH-4610A, and BGH-5472A were the most promising for seed oil production. These last two accessions corresponded to those with higher seed productivity, averaging 0.58 and 0.54 t ha-1, respectively. This study confirms the high potential of this germplasm for use in breeding for promotion of earlier flowering and increase in total content of fruit pulp carotenoids and in seed and seed oil productivity.

Comparative analysis of constitutive proteome between resistant and susceptible tomato genotypes regarding to late blight.

Late blight is one of the most destructive diseases of the tomato, resulting in substantial economic losses. There is difficulty in controlling this disease, so the molecular characterization of tomato genotypes may help in the selection of higher resistance tomato plants against Phytophthora infestans, late blight's pathogen. The objective was to analyze the differences with regard to the constitutive proteome between the access Vegetable Germplasm Bank (BGH)-2127, resistant genotype, and Santa Clara-susceptible genotype to late blight. Proteomic analysis of leaf samples by two-dimensional electrophoresis (2-DE) followed by identification by mass spectrometry (MALDI TOF/TOF) was performed. Nineteen proteins were identified, which were then related to metabolism and energy, photosynthesis, transcription, stress, and defenses. Approximately 90% of these proteins were more abundant in Santa Clara, a susceptible cultivar. Acidic 26 kDa endochitinase and ribonuclease T2 proteins were more abundant in BGH-2127 access. The enzymatic activity confirmed a greater abundance of chitinase in the BGH-2127 access as compared to the cultivar Santa Clara. Gene expression analyses by real-time PCR demonstrated that the mRNA levels were not correlated with the respective protein levels. Abundance of the acidic 26 kDa endochitinase and ribonuclease T2 proteins in the constitutive proteomes of BGH-2127 may be associated with the answer to the resistance of this access.

Spacial distribution of fertigated coffee root system / Distribuição espacial do sistema radicular do cafeeiro fertirrigado

ABSTRACT The development of coffee plant root system changes when subjected to drip irrigation and fertigation. This work aimed to evaluate the effects of different levels of fertigation on the development of coffee root system by drip irrigation in western Bahia. The experiment was carried out with Catuaí Vermelho IAC 144 coffee plants, of about 3.5 years of age, in the "Café do Rio Branco" farm, located in Barreiras - BA, and consisted of a complete randomized blocks design with 3 replicates. Treatments consisted of three levels of nitrogen and potassium fertilization (900/800, 600/500 and 300/250 kg ha-1 year-1 N and K2O), weekly distributed, by means of fertigation, throughout the process. After the fourth harvest, coffee root system was evaluated, and root length density (RLD) and root density (RD) were determined at different sampled layers. The highest root concentration, root length density (RLD), and root density (RD) were observed in the superficial layers of soil (0-20 cm), and under the dripline (30 and 70 cm from the orthotropic branch). Results showed that the lower the N and K2O levels, the higher was the development (RLD and RD) of the coffee root system.

RESUMO O desenvolvimento do sistema radicular do cafeeiro é alterado quando submetido à irrigação localizada e fertirrigação. Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos de diferentes doses de fertirrigação sobre o desenvolvimento do sistema radicular do cafeeiro irrigado por gotejamento na região Oeste da Bahia. Realizou-se o trabalho na fazenda Café do Rio Branco, localizada em Barreiras - BA, em cafeeiros de aproximadamente 3,5 anos de idade, da variedade Catuaí IAC 144. O experimento foi montado em um esquema fatorial 3 x 3, sendo três níveis de adubação nitrogenada e potássica (900/800, 600/500 e 300/250 kg ha-1 ano-1 de N e K2O), em 3 parcelamentos mensais de fertirrigação (2, 4 e 8 vezes). Após a quarta safra, o sistema radicular do cafeeiro foi avaliado e a densidade de comprimento radicular (DCR) e densidade radicular (DR) em diferentes camadas amostradas foram determinadas. A maior concentração de raízes, densidade de comprimento radicular (DCR) e densidade radicular (DR) foi obtida nas camadas superficiais (0-20 cm) e sob a linha lateral (30 e 70 cm de distância do ramo ortotrópico). As menores doses de N e K2O propiciaram maior desenvolvimento (DCR e DR) do sistema radicular do cafeeiro.

Produtividade e rendimento industrial da cana-de-açúcar em função de lâminas de irrigação / Productivity and industrial yield of sugarcane as a function of irrigation depths

O presente trabalho foi desenvolvido com o objetivo de determinar as lâminas de irrigação que resultem na máxima produtividade, no máximo rendimento econômico e no máximo rendimento industrial da cana-deaçúcar e a relação existente entre a lâmina de água e a formação de dextrana. O experimento foi instalado em outubro de 2010 em Jaíba/MG, em uma área irrigada por pivô central, com cana-de-açúcar no quarto ciclo de produção. Para a aplicação dos tratamentos, trocaram-se os bocais dos emissores, em cada vão entre torres do pivô central, de modo que fossem aplicadas as lâminas referentes a 25, 50, 75, 100, 125 e 150% da evapotranspiração da cultura, com o manejo da irrigação realizado para atender a demanda de 100%. Determinou-se a produtividade de colmos e o rendimento industrial da cana-de-açúcar, expressos em açúcares totais recuperáveis (ATR) e os teores de dextrana. Com os dados de produtividade e os custos relacionados à irrigação, calculou-se as lâminas para obtenção da máxima produtividade física (Lmpf) e do máximo rendimento econômico (Lmre), considerando-se a produtividade de colmos e de açúcares. Analisando-se os resultados obtidos, concluiu-se que: a lâmina que proporcionou a maior produtividade de colmos foi de 1.537 mm, para a produtividade de 112,3 t ha-1, ou seja, são necessários 136,9 m3 de água para se produzir uma tonelada de colmos. A lâmina de maior rendimento econômico foi de 1.334 mm para uma produtividade de 108,5 t ha-1. O maior rendimento de açúcares (158,1 kg t-1) foi obtido com lâmina de 1.373 mm. A lâmina que proporcionou a maior produtividade de açúcares (17,56 t ha-1) foi de 1.508,4 mm. O melhor rendimento econômico, em termos de açúcares por unidade de área, foi de 17,4 t ha-1(lâmina recomendada), com fornecimento de 1.406 mm de água, resultando na necessidade de 808 m3 de água para se produzir uma tonelada de açúcar. Lâminas acima de 1.000 mm no ciclo da cultura promoveram teores de dextrana acima dos limites estabelecidos para produção de açúcar. Recomenda-se para as indústrias de etanol e, principalmente de açúcar, introduzirem as análises de dextrana na rotina laboratorial.

The present work was developed due to determine the irrigation depths that result in the maximum productivity, maximum economic yield and the maximum industrial yield of sugarcane, and the relationship between water depth and the formation of dextran. The experiment was installed in October 2010 in Jaíba/MG, Brazil, in an area irrigated by a center pivot with sugarcane in the fourth cycle. For the application treatments the emitter nozzles were exchanged so that the depths were applied referring to 25, 50, 75, 100, 125 and 150% of crop evapotranspiration with irrigation management performed to meet the 100% of the demand. Stalk productivity and industrial yield of sugarcane were determined, as well as levels of ATR and dextran. With productivity data and irrigation costs, the maximum productivity (Lmpf), and maximum economic yield (Lmre) were calculated considering the stalk and sugar yields. The values obtained were subjected to analysis of variance and subsequently developed regressions. Analyzing the results, it was concluded that: the depth that provided the highest stalk yield was 1,537 mm, for a yield of 112.3 t ha-1, i.e. 136,9 m3 of water are necessary do produce one ton of stalks. The depth resulting in greatest economic yield was 1,334 mm for a yield of 108.5 t ha-1. The greatest sugar yield (158.1 kg t-1) was obtained with the depth of 1,373.1 mm. Highest sugar yield (17.56 t ha-1) was obtained from the depth of 1,508 mm. The best economic performance, in terms of sugar per unit area was 17.4 t ha-1, with supply of 1,405.9 mm of water, resulting in a water demand of 808 m3 to produce one ton of sugar. The best economic performance, in terms of sugar per unit area was 17.4 t ha-1 with the supply of 1,406 mm of water (recommended depth). Irrigation depths up to 1,000 mm in the crop cycle promoted dextran levels above the limits established for sugar production. It is recommended that the ethanol industries, and especially sugar industries, utilize dextran analyses in the laboratorial routine.

Indicadores morfo-fisiológicos do estresse hídrico para a cultura da cana-de-açúcar em função de lâminas de irrigação / Morpho-physiological indicators of water stress on sugarcane as a function of irrigation depths

O presente trabalho foi desenvolvido, objetivando-se encontrar as relações entre lâmina de água (chuva e irrigação) e indicadores morfológico (índice de área foliar) e fisiológicos do estresse hídrico (temperatura foliar, potencial hídrico foliar e índice de clorofila nas folhas) na cana-de-açúcar submetida a diferentes lâminas de irrigação. O experimento foi instalado em outubro de 2010 em Jaíba/MG, em uma área irrigada por pivô central, com cana-de-açúcar no quarto ciclo. Para a aplicação dos tratamentos, trocaram-se os bocais dos emissores, em cada vão entre torres, de modo que fossem aplicadas as lâminas referentes a 25, 50, 75, 100, 125 e 150% da evapotranspiração da cultura, com o manejo da irrigação realizado para atender a demanda de 100%. Foram medidos o índice de área foliar, o potencial hídrico foliar, a temperatura foliar e o índice de clorofila nas folhas. Os valores obtidos foram submetidos a análises de variância e, posteriormente, elaboradas regressões. Diante dos resultados, foi possível concluir que houve tendência de aumento do índice de área foliar (IAF) da cana-de-açúcar à medida que se aumentou a lâmina de irrigação no ciclo da cultura; o aumento do IAF foi mais acentuado nos tratamentos que receberam mais água; o potencial hídrico foliar foi menor para menores lâminas de irrigação, com destaque para o tratamento que recebeu menos água (25%); a temperatura foliar foi próxima à temperatura do ar nos tratamentos que receberam as maiores lâminas (100 a 150%), com tendência de aumento da diferença entre a temperatura das folhas, à medida que se reduziu o suprimento hídrico; houve tendência de aumento do índice de clorofila (ICF) à medida que se aumentou as lâminas, com leve queda nos tratamentos que receberam lâminas maiores que 100% da ETc.

The present study was developed to evaluate relationships between the water depths (rain and irrigation) and morphological (leaf area index) and physiological indicators (leaf temperature, leaf water potential and chlorophyll content in leaves) of water stress on sugarcane subject to different irrigation levels. The experiment was installed in October 2010 in Jaíba/MG, Brazil, in an area irrigated by a center pivot system with sugarcane in the fourth cycle. For the treatments, emitter nozzles were exchanged in each vain between pivots so that the depths applied related to 25, 50, 75, 100, 125 and 150% of evapotranspiration, with the irrigation management performed to meet 100% of the demand. The factors of leaf area index, leaf water potential, leaf temperature and leaf chlorophyll index were measured. The values obtained were subjected to analysis of variance and subsequently developed regressions. From the results, it was concluded that there was a trend of increased leaf area index (LAI) for sugarcane as increasing the water depth in the crop cycle; the increase in LAI was more pronounced in treatments that received more water; leaf water potential was lesser for smaller irrigation depths, with emphasis on the treatment that received less water (25%); leaf temperature was close to the air temperature in the treatment receiving the highest depths (100 and 150%) with a trend for an increased difference between the temperature of the leaves as reducing the water supply; the chlorophyll index (ICF) tended to increase as increasing the depths, with a slight drop in treatments receiving depths greater than 100% of the ETc.