Claudete Aparecida Mangolin

This study aimed to investigate the combining ability and heterotic effects on grain yield (GY), oil content (OC) and crude protein (CP) in tropical and temperate maize lines. Hybrids and inbred lines were evaluated in a complete diallel scheme without reciprocals, in two experiments in randomized blocks with three replications. The partitioning of the sum of squares for general (GCA) and specific (SCA) combining ability indicated that both additive and non-additive effects were involved in the genetic control of the studied traits. The estimates of the quadratic components showed predominance of non-additive genetic effects in the trait control. However, for OC and CP, the non-additive effect had a clearly negative influence on the hybrid combinations. The cross L6x L10was considered promising, because it associated RG positively with BP and OC.

No previous studies have investigated the use of graphite instead of activated charcoal in orchids. In this work, different concentrations of activated charcoal or graphite were added to KC medium to darken the culture medium and stimulate the in vitro propagation of Cattleya bicolor and of a double hybrid orchid (‘BLC Pastoral Innocence’). The seedlings were inoculated on growth regulator-free KC medium; the effects of activated charcoal (0.0, 1.5, 3.0, 4.5, 6.0, and 7.5 g L^-1) and graphite (0.0, 1.5, 3.0, 4.5, 6.0, and 7.5 g L^-1) concentrations were tested separately. Each flask contained fifteen seedlings, and the experiments had a randomised, two-way factorial design. The two tested variables were culture medium and illumination levels; eleven culture levels (different concentrations of graphite or activate charcoal) and two illumination levels (14-hr photoperiod or continuous illumination) were evaluated. Three replicates of each combination were utilised. After six months of culture, the average numbers of induced buds and roots per seedling were recorded for each concentration of activated charcoal or graphite. Whereas the largest number of buds in C. bicolor seedlings occurred on media containing 6.0 or 7.5 g L^-1 graphite, the largest number of roots occurred on media containing 6.0 g L^-1 activated charcoal. In the hybrid ‘BLC Pastoral Innocence’, the largest number of buds and roots was reported in medium with 4.5 g L^-1 activated charcoal. When using graphite in place of activated charcoal, we obtained disparate the results in root formation that suggest that graphite is not a recommended substitute for activated charcoal.

Tecidos de calos em cultura prolongada de Cereus peruvianus foram utilizados para investigar a produção de alcalóides pelos calos quando mantidos em meio de cultura suplementados com diferentes concentrações de tirosina, com diferentes níveis de 2,4-D/cinetina, e contendo NaCl. Foi analisado também, o padrão de isozimas α- e β-esterases, para investigar a expressão diferencial de genes nos calos subcultivados com as diferentes concentrações de tirosina. A maior quantidade de alcalóides foi obtida a partir de calos mantidos em meio contendo 200 mg/L de tirosina. A adição de tirosina no meio induziu uma expressão gênica diferencial para a síntese de isozimas α- e β-esterases. Duas α-carboxilesterases (EC 3.1.1.1) e uma α/β-arilesterase (EC 3.1.1.2) foram induzidas nos calos, uma α/β-acetilesterase (EC 3.1.1.6) e uma α-carboxilesterase foram detectadas como bandas mais intensamente coradas, enquanto duas α/β-carboxilesterases não foram detectadas ou foram fracamente coradas após a adição de tirosina como precursor no meio de cultura