ABSTRACT Considering that the beneficial effects of silicon on human health and it´s accumulation in plants are little explored, studies of mineral nutrition in non-conventional vegetables are extremely relevant. Thus, the objective of this work was to identify non-conventional vegetables responsive to silica fertilization and evaluate the effect of fertilization on the content and accumulation of Si and macronutrients in these plants. The experiment followed a 4 x 5 factorial design, with four species of non-conventional vegetables (Rumex acetosa L., Amaranthus retroflexus L., Sonchus oleraceus L. and Stachys byzantina) and five doses of Si (0, 25, 50, 100 and 150 mg dm-3). The relative chlorophyll index, the fresh and dry matter masses, the content and accumulation of Si and macronutrients were evaluated. The species A. retroflexus, S. oleraceus. and S. byzantina showed the highest contents and accumulation of Si. The application of doses above 100 mg dm-3 promoted the highest silicon content estimated for the species. The species A. retroflexus, R. acetosa and S. byzantina are non-silicon accumulators, whereas S. oleraceus is intermediate.

Resumo: O objetivo deste trabalho foi avaliar o uso de marcadores moleculares RAPD e ISSR para determinar a variabilidade genética entre genótipos de cajueiro (Anacardium spp.) e indicar possíveis cruzamentos promissores com base na variabilidade genética e no desempenho fenotípico do cajueiro. Foram avaliados, em nível molecular, dez híbridos - originados dos cruzamentos CCP 76 x BGC 589, CCP 76 x BRS 226, CCP 76 x HAC 276-1, CCP 76 x Embrapa 51, CCP 76 x BRS 253, CCP 76 x HAC222-4 e BRS226 x Embrapa 51 - e seus respectivos genitores. Os híbridos foram avaliados quanto à produção de castanha, à massa média da castanha, à incidência de castanhas furadas e à incidência de oídio na castanha (escala 0-4). Os marcadores RAPD e ISSR foram eficientes em determinar a variabilidade genética entre esses genótipos de cajueiro, tendo permitido o agrupamento de 21 grupos. Associados à caracterização fenotípica da castanha de caju quanto à produtividade, à massa e à sanidade da castanha, os marcadores utilizados são eficientes para identificar possíveis combinações capazes de proporcionar maior variabilidade genética e maior probabilidade de obtenção de genótipos transgressivos em populações segregantes.

Abstract: The objective of this work was to evaluate the use of RAPD and ISSR molecular markers to determine the genetic variability among cashew (Anacardium spp.) genotypes, and to indicate possible promising crosses based on cashew genetic variability and phenotypic performance. Ten hybrids - derived from the crosses CCP 76 x BGC 589, CCP 76 x BRS 226, CCP 76 x HAC 276-1, CCP 76 x Embrapa 51, CCP 76 x BRS 253, CCP 76 x HAC222-4, and BRS226 x Embrapa 51 - and their parents were assessed at the molecular level. The hybrids were evaluated for nut yield, mean nut weight, bored nuts, and powdery mildew on nuts (scale 0-4). The RAPD and ISSR markers were efficient in the determinaton of the genetic variability among cashew genotypes, allowing of the grouping of 21 clusters. Associated with the phenotypic characterization of cashew nut for yield, weight, and health, the used markers can efficiently identify possible combinations with higher genetic variability and higher probability of developing transgressive genotypes in segregating populations.