Diego Pascoal Golle

Estabelecimento e desenvolvimento in vitro de Eugenia involucrata DC.: influência do tipo de explante e do meio nutritivo

Apresentando diversas caracteristicas de interesse nos setores da silvicultura, fruticultura, meio ambiente e medicinal, Eugenia involucrata DC. (Myrtaceae) e uma especie florestal nativa de varios Estados brasileiros. Considerada a dificuldade da propagacao por sementes, que sao recalcitrantes, perdendo rapidamente sua viabilidade apos a colheita, este trabalho objetivou avaliar a influencia do uso de segmentos apicais e nodais cultivados em diferentes meios nutritivos no estabelecimento e no desenvolvimento in vitro desta especie. Segmentos apicais e nodais coletados em plantas de tres anos de idade, mantidas em casa de vegetacao, foram inoculados nos meios nutritivos MS, ½ MS e WPM. Em um primeiro momento, adicionaram-se aos meios de cultura 1 μM de ANA e 5 μM de TDZ e, apos, os explantes foram transferidos para frascos contendo os respectivos meios nutritivos frescos, na ausencia de reguladores de crescimento, mas com o acrescimo de 1 g L-1 de carvao ativado, sendo cultivados por 30 dias adicionais. Os meios ½ MS e WPM sao adequados para o estabelecimento e o desenvolvimento in vitro a partir do cultivo de segmentos nodais, enquanto que, com segmentos apicais, e apropriado o meio ½ MS. O meio ½ MS possibilitou os melhores indices de enraizamento nos explantes, juntamente com o meio WPM. O estabelecimento e o enraizamento in vitro foram promovidos pelo cultivo de segmentos apicais e nodais de Eugenia involucrata DC. Os meios nutritivos ½ MS e WPM sao apropriados para o cultivo in vitro de segmentos nodais de E. involucrata, recomendando-se o meio ½ MS pela economia e praticidade. Para segmentos apicais, o uso do meio de cultura ½ MS e mais adequado que o dos meios MS e WPM.

Substratos alternativos e tratamentos pré-germinativos na germinação in vitro de sementes de Pinus taeda L.

The aims of this paper were to develop protocols to obtain in vitro seedlings of P. taeda, evaluate the use of alternative substrates as well as analyze the effect of pre-germinative treatments for optimizing germination. Disinfestation treatments using sodium hypochlorite, influence of photoperiod and pre-germinative treatments, and the possibility of using alternative substrates (maize star ch, filter paper, hydrophile cotton, vermiculite, agar-water and addition of activated charcoal into the nutritive medium) were tested for germination. In vitro germination, fungal and bacterial contamination were evaluated. The best seed disinfestation treatment was ethanol at 70 % for 30 seconds + sodium hypochlorite at 3 % for 5 minutes. However , it caused a toxic effect. Alternative substrates provide adequate physical conditions to tissue culture, but do not favor germination. Nevertheless, the use of hydrophile cotton associated with seed soaking for 72 hours, without disinfestation, enhances germination and provides in vitro seedlings with low contamination.

Desinfestação superficial, germinação e regeneração in vitro a partir de sementes de calêndula

The aims of this paper were: to develop a protocol of superficial disinfestation of marigold seeds; to select a methodology of germination in vitro of marigold seeds; to evaluate the potential regeneration of in vitro culture of marigold; and the influence of in vitro culture time in the kind of callus formed. The superficial disinfestation was perfomed by different times of immersion in 2.5% sodium hypoclorite solution. The methodology was tested by immersion in sulfuric acid; immersion in chloridric acid; removal of tegument and soaking of seeds; and just seeds soaking. To evaluate the potential of in vitro regeneration were tested different concentrations of growth regulators and culture times. The immersion in 2.5% sodium hypochlorite solutions for 30min coupled with the removal of tegument promote the in vitro germination and superficial disinfestation of marigold seeds satisfactorily. Primary calli in BAP presence, with or without ANA, induce formation of spongy and friable calli and of green and hard calli, these are in least amount. Young calli are more efficient to regenerate aerial parts.

In vitro rhizogenesis and acclimatization of Peltophorum dubium shoots: effect of adding agar to a WPM/2 medium with vermiculite

Peltophorum dubium (Sprengel) Taubert is a forest tree that is native to Brazil and that has ecological and economic importance. Preliminary studies on the micropropagation of the species covered aspects of the in vitro establishment and multiplication and indicated that it has potential for this type of asexual propagation. The present study evaluated the in vitro rhizogenesis of P. dubium shoots via micropropagation on different culture media with different concentrations of sucrose, auxin, and agar and analyzed the subsequent in vitro acclimatization of the plantlets. Rhizogenesis was evaluated on half-strength Woody Plant Medium nutritive medium that contained 30 cm3 vermiculite and different concentrations of sucrose (0, 15, or 30 g·L1), the auxin indole-3-butyric acid (0 or 10 μM), and agar (0 or 7 g·L-1). Rooting shoots were transferred to a substrate for in vitro acclimatization. The best medium both for rhizogenesis (producing roots in 44.43% of cases); and for in vitro acclimatization contained 7 g·L-1 agar but no sucrose or auxin. The addition of agar to the medium in the absence of sucrose and indole-3-butyric acid resulted in a better quality radicular system in micropropagated shoots of P. dubium and with a satisfactory survival rate of the plantlets during in vitro acclimatization.

Multiplicação in vitro de segmentos apicais caulinares de segurelha (Satureja hortensis L.)

This study aimed to evaluate the effect of BAP in the presence and absence of NAA, on the in vitro multiplication of shoot apical segments of Satureja hortensis. The explants were isolated from seedlings germinated in vitro and cultured in nutrient medium MS. The experimental design was completely randomized in a 2x5 factorial arrangement, corresponding to the concentrations of NAA (0 and 1 µM) and BAP (0, 5, 10, 15 and 20 µM), with six replicates, each consisting of three explants. For the percentage of explants with shoots, there was no significant effect for the factor BAP, increasing as the concentration of BAP grows. The variable number of shoots per explant showed interaction between factors, with the highest shoot formation in the presence of NAA and BAP in the range of 10 -15 µM. In the presence of auxin, the highest value occurred with 15 µM BAP, tending to decline regardless of the presence of NAA. The rooting of the apical segments was higher in the presence of NAA and absence of BAP, decreasing with increasing cytokinin. Leaf number was influenced by the higher concentration of BAP, and the amount of 15 µMhadthe largest number, tending to decrease with increasing concentration. The concentration of 15 µM BAP, regardless of NAA, provided better results in the multiplication of the species, producing increased number of shoots and leaves, except for rooting, whichwas influenced by auxin.

Subsídio hídrico fornecido por substratos alternativos usados na germinação in vitro de Pinus taeda L.

The aim of this study was to assess the water supply provided by different alternative substrates as well as to analyze its efficiency in the sanity and in the in vitro germination of Pinus taeda L. seeds. The seeds were inoculated in filter paper, hydrophile cotton and agar-water medium. Water absorption by seeds was assessed for 3, 6, 9, 24, 48 and 72h and, later, at 21 days of cultivation and contamination by microorganisms was determined. Water absorption, based on the percentage increase which occurred in the weight of seeds, was higher in filter paper and hydrophile cotton. The best germination rates were obtained with filter paper and agar-water. However, agar-water presented the highest contamination rates. Due to water loss in the substrate filter-paper during cultivation, it is suggested the use of cotton because of the low contamination rates observed.