ABSTRACT: In the last decades, a new trend to use more refined analytical procedures, such as artificial neural networks (ANN), has emerged to be most accurate, efficient, and extensively applied for mining and data prediction in different contexts, including plant breeding. Thus, this study was developed to establish a new classification proposal for targeting genotypes in breeding programs to approach classical models, such as a complete diallel and modern prediction techniques. The study was based on the standard deviation values of an interpopulation diallel and it also verified the possibility of training a neural network with the standardized genetic parameters for a discrete scale. We used 12 intercrossed maize populations in a complete diallel scheme (66 hybrids), evaluated during the 2005/2006 crop season in three different environments in southern Brazil. The implemented MLP architecture and other associated parameters allowed the development of a generalist model of genotype classification. The MLP neural network model was efficient in predicting parental and interpopulation hybrid classifications from average genetic components from a complete diallel, regardless of the evaluation environment.

Abstract: In many agricultural crops, the number of parents used in cross breeding make it difficult to obtain all possible hybrids in diallels. Therefore, using maize as a model plant and based on traits with high and low heritabilities, the aim of the present study was to quantify the correlation estimates of the general combining ability (GCA) and specific combining ability (SCA) between a complete diallel and a circulant diallel, with and without the inclusion of parents. For the high heritability trait, the GCA estimates can be obtained with low s values, whereas for the SCA estimates, s values close to half the number of parents should be used. For the low heritability trait, information from parents must be used to obtain the SCA estimates. For the GCA estimates, considering the stabilization of r above 0.70 for s=7, s values greater than half the number of parents must be used in the circulant models.

ABSTRACT Grapevine decline and death caused by the pathogenic fungus Fusarium oxysporum f. sp. herbemontis is among the main phytosanitary problem for viticulture in southern Brazil. The eradication of infected plants is presently the most common procedure for disease control in vineyards. Inoculation with arbuscular mycorrhizal fungi is an option to reduce or neutralize the negative impacts of soil pathogenic microorganisms, but the mechanisms of plant response involved in this process are not yet completely elucidated. In order to better understand these mechanisms, an experiment was carried out to identify proteins related to plant defence induced by the mycorrhizal fungus after infection with the pathogenic fungus. We used the grapevine rootstocks SO4 and R110 (susceptible and resistant to the pathogenic fungus, respectively) inoculated or not inoculated with the mycorrhizal fungus Rhizophagus irregularis, and inoculated or not inoculated with Fusarium oxysporum f. sp. herbemontis. Growth of the rootstocks’ shoot and root and presence of pathogenic symptoms were evaluated. The protein profiles of roots were characterized by two-dimensional electrophoresis and proteins were identified using mass spectrometry. The grapevine rootstocks inoculated with R. irregularis had higher biomass production and lower level of pathogenic symptoms. The R110 rootstock differentially accumulated 73 proteins, while SO4 accumulated 59 proteins. Nine plant-defence proteins were expressed by SO4 rootstock, and six were expressed by R110 rootstock plants. The results confirm the effect of mycorrhizal fungi in plant growth promotion and their potential for biological control against soil pathogenic fungus. Protein expression is dependent on rootstock characteristics and on the combination of plant material with the fungi.

O objetivo deste trabalho foi quantificar os teores de proteína, amido e açúcares totais durante a histodiferenciação e desenvolvimento dos embriões somáticos em Acca sellowiana Berg. Para as observações histológicas, as amostras foram desidratadas em uma bateria de etanol, emblocadas em historesina e coradas com azul de toluidina (morfologia), azul de coomassie (corpos proteicos) e reativo ácido periódico de Schiff (amido). As proteínas foram extraídas usando uma solução tampão, precipitadas usando etanol e quantificadas por meio do reativo de Bradford. Os açúcares totais foram extraídos usando uma solução metanol-clorofórmioágua (12:5:3) e quantificados pela reação com antrona a 0,2%. O amido foi extraído usando uma solução de ácido perclórico a 30% e quantificado pela reação com antrona a 0,2%. Durante a diferenciação e morfogênese in vitro da embriogênese somática, os teores de proteínas totais decresceram e os açúcares solúveis aumentaram durante os 30 primeiros dias em cultura e permaneceram constantes até os 120 dias. Por outro lado, os teores das proteínas totais apresentaram incremento de acordo com a progressão nos estádios de desenvolvimento dos embriões somáticos. Os teores de açúcares totais e de amido aumentaram nos estádios cordiforme e cotiledonar e diminuíram nos estádios torpedo e pré-cotiledonar. Esses compostos exercem papel central no desenvolvimento de embriões somáticos de Acca sellowiana.

The aim of this work was to quantify the protein, starch and total sugars levels during histodifferentiation and development of somatic embryos of Acca sellowiana Berg. For histological observations, the samples were dehydrated in a battery of ethanol, embedded in historesin and stained with toluidine blue (morphology), coomassie blue (protein bodies) and periodic acid-Schiff (starch). Proteins were extracted using a buffer solution, precipitated using ethanol and quantified using the Bradford reagent. Total sugars were extracted using a methanol-chloroform-water (12:5:3) solution and quantified by a reaction with anthrone at 0.2%. Starch was extracted using a 30% perchloric acid solution and quantified by a reaction with anthrone at 0.2%. During the somatic embryogenesis' in vitro morphogenesis and differentiation processes, the total protein levels decreased and the soluble sugars levels increased during the first 30 days in culture and remained stable until the 120th day. On the other hand, total protein levels increased according to the progression in the developmental stages of the somatic embryos. The levels of total sugars and starch increased in the heart and cotyledonary stages, and decreased in the torpedo and pre-cotyledonary stages. These compounds play a central role in the development of somatic embryos of Acca sellowiana.