ANTIOXIDANTS, SUCROSE AND AGAR IN THE IN VITRO MULTIPLICATION OF Eremanthus incanus

The objective of this study was to evaluate the in vitro multiplication of Eremanthus incanus axillary buds in the presence of PVP additives and activated charcoal under the interaction of different sucrose and agar concentrations. Explants containing axillary buds were inoculated in MS culture medium to evaluate the effect of 0.8 g L-1 of PVP and 1.0, 2.0 and 4.0 g L-1 of activated charcoal. The results of the addition of 0, 15, 30, and 60 g L-1 of sucrose combined with concentrations of 6 and 10 g L-1 of agar in MS medium were also evaluated. The number and quality of emitted shoots were evaluated after 30 and 60 days. The addition of PVP to the culture medium was more efficient than the use of activated charcoal in the multiplication of the species. The presence of sucrose is indispensable for developing the shoots well, and the use of a lower concentration of agar favors the development of quality shoots. The best results for shoot multiplication were obtained using 30 g L-1 sucrose and 6 g L-1 agar. PVP, activated charcoal, agar and sucrose are important components in the culture medium and alter the in vitro multiplication of Eremanthus incanus.The objective of this study was to evaluate the in vitro multiplication of Eremanthus incanus axillary buds in the presence of PVP additives and activated charcoal under the interaction of different sucrose and agar concentrations. Explants containing axillary buds were inoculated in MS culture medium to evaluate the effect of 0.8 g L-1 of PVP and 1.0, 2.0 and 4.0 g L-1 of activated charcoal. The results of the addition of 0, 15, 30 and 60 g L-1 of sucrose combined with concentrations of 6 and 10 g L-1 of agar in MS medium were also evaluated. The number and quality of emitted shoots were evaluated after 30 and 60 days. The addition of PVP to the culture medium was more efficient than the use of activated charcoal in the multiplication of the species. The presence of sucrose is indispensable for developing the shoots well, and the use of a lower concentration of agar favors the development of quality shoots. The best results for shoot multiplication were obtained using 30 g L-1 sucrose and 6 g L-1 agar. PVP, activated charcoal, agar and sucrose are important components in the culture medium and alter the in vitro multiplication of Eremanthus incanus

EMERGENCE, INITIAL GROWTH, AND SEEDLING QUALITY OF Eremanthus incanus: SUBSIDIES FOR GENETIC BREEDING AND CONSERVATION

ABSTRACT So far, the commercial production of Eremanthus incanus seedlings has been performed with seeds without any genetic control. Thus, we propose two experiments to examine seed-trees' effect on their descendants via the seminal in the nursery phase and verify the correlation between the variables. We installed the first experiment in a greenhouse and evaluated seedling emergence weekly for 42 days. At the exit of the greenhouse, at 60 days, we estimated survival. We conducted the second experiment in a shade house and, later, in full sun. We evaluated seedlings' height, diameter, and survival at 90, 120, 150, and 180 days after sowing. At 180 days, we quantified shoot, root, and total dry matter weight and calculated the Dickson Quality Index (DQI). The effects of E. incanus seed-trees on their descendants via the seminal were significant for emergence, growth characteristics, and seedling quality. The seedling survival rate at the greenhouse exit was high for all seed-trees, ranging from 72.2% to 97.2%. All seed-trees showed greater biomass allocation in the shoots of the seedlings, with this proportion being more pronounced in some of them. Although not significant, the correlation estimates between the emergence rate and the other traits were all positive. The correlations between height, diameter, dry mass, and DQI were significant and positive, from moderate to high magnitude. Due to its nondestructive nature, the diameter can be considered the most suitable practical indicator to evaluate the quality of E. incanus seedlings. Our results substantially contribute to implementing more effective conservation and breeding strategies, helping to understand the behavior of E. incanus in Campos Rupestres environments regarding seedling production and recovery of ecosystem services

In vitro clonal hedge in the vegetative propagation of Eucalyptus spp

O sucesso da produtividade nos plantios de Eucalyptus no Brasil tem sido função da combinação de diversos fatores, entre os quais encontra-se os avanços das tecnologias da propagação clonal. A produção de miniestacas a partir do minijardim clonal em viveiro é a principal metodologia adotada para produção de mudas de Eucalyptus, com avanços importantes em produtividade, controle ambiental e fitossanitário; no entanto, ainda com algumas limitações e desafios. Como alternativas, a micropropagação tem sido considerada como promissora na produção de mudas clonais, havendo porém, limitações à sua adoção, como a necessidade de estrutura física e operacional de um laboratório, e de protocolos ajustados para cada material vegetal. Assim, objetiva-se nesse trabalho verificar a viabilidade de um jardim clonal in vitro por meio da avaliação de diferentes composições de substratos, tipos e tamanhos de recipientes, formas de vedação, concentrações de sacarose e diferentes intensidades e qualidade de luz. Avaliou-se em dez genótipos de Eucalyptus, diferentes tipos de recipientes e substratos. O recipiente frasco de vidro de 250 mL de capacidade permitiu melhor crescimento das plantas. O ágar e a vermiculita foram os substratos que possibilitaram melhor crescimento in vitro. Além das diferenças observadas entre substratos e recipientes, constatou-se efeito do fator genético sobre as características, o que possibilita a seleção de clones para propagação sob as condições avaliadas. Para estabelecimento de jardim clonal in vitro, sob condições que estimulam o comportamento fotoautotrófico, testou-se a ausência e presença de membranas para trocas gasosas, bem como diferentes concentrações de sacarose na formação inicial da microcepa. A sacarose foi importante, inicialmente, com resultados crescentes para todas as características com o uso de concentrações até 20 g L -1 , exceto para número de estacas obtidas aos 150 dias. A presença de membranas para maiores trocas gasosas nos frascos permitiu melhor crescimento das microestacas, tanto in vitro quanto ex vitro. Fontes luminosas fluorescentes e LED proporcionaram crescimento de microestacas in vitro, apresentando diferenças para algumas características analisadas. Em relação à intensidade luminosa, não foi observada diferença no crescimento das microcepas. O jardim clonal in vitro apresentou maior produtividade por área de microestacas comparativamente ao sistema convencional de produção de miniestacas no minijardim clonal, sendo as taxas de enraizamento e sobrevivência semelhantes nos dois sistemas. No entanto, acompanhamento em diferentes estações do ano, padrões de minijardins clonais, avaliações com diferentes genótipos (clones), assim como viabilidade técnica, operacional e econômica devem ser realizadasThe production of mini-cuttings from mini-clonal hedge in nursery stage is the most adopted methodology for the production of Eucalyptus plantlets, with important advances in productivity and environmental and phytosanitary control; however, there is still some limitations and difficulties. As an alternative, micropropagation has been considered promising in the production of clonal plantlets, but there are limitations to its adoption, such as the need for a physical and operational structure of a laboratory, and protocols to be adjusted for each species. The objective of this work was to verify the efficiency of an in vitro clonal hedge through the evaluation of different substrates compositions, types of vessels, forms of sealing, sucrose concentrations and different light intensities and quality. For this, ten Eucalyptus genotypes, different types of vessels and substrates were evaluated. As a result, the vessel that allowed the best plant growth was the 250 mL glass flask. For the substrate, agar and vermiculite enabled better in vitro growth of the plants. In addition to the differences observed among substrates and vessels, genetic control of the characteristics was also verified, which allows the selection of clones for propagation under those conditions. For the establishment of an in vitro clonal hedge, under conditions that stimulate photoautotrophy, the absence and presence of membranes that allow gas exchange, as well as different sucrose concentrations in the initial formation of micro-stumps were tested. Sucrose was important initially, and increasing results were observed with the use of concentrations up to 20 g L -1 for all characteristics except for number of cuttings obtained at 150 days. The presence of membranes that allow higher gas exchange led to a better development of the micro-cuttings both in vitro and ex vitro. Fluorescent and LED lights provided good plant development, showing differences for some characteristics analyzed. Regarding the intensity, no difference was observed in the development of micro-stumps. When comparing the mini-cutting/micro-cutting production, the conventional mini-clonal hedge system and the in vitro clonal hedge system show higher productivity per area in the in vitro clonal hedge, with rooting and survival rates being similar in both systems. However, monitoring in different seasons of the year, establishment of patterns of mini-clonal hedge, evaluations with different genotypes (clones), as well as technical, operational and economic viability should be performedCoordenação de Aperfeiçoamento de Pessoal de Nível Superio

LIGHT QUALITY IN THE IN VITRO INTRODUCTION OF Corymbia HYBRID CLONES

ABSTRACT Micropropagation via axillary bud proliferation is recommended for rejuvenation or reinvigoration of selected clones, as well as for improving clonal seedlings rooting. The success of a micropropagation protocol depends on the in vitro introduction, since following phases, multiplication, elongation, and rooting can only take place once the aseptic crop with vegetative vigor has been established. This study aims to assess the effect of light on the in vitro introduction of hybrid clones of Corymbia torelliana x C. citriodora e Corymbia citriodora x C. torelliana by the micropropagation technique through proliferation by axillary buds. The mini-stumps, suppliers of explants for in vitro introduction, were conducted in semi-hydroclonal mini-clonal hedge. Nodal segments from three Corymbia torelliana x C. citriodora (TC01, TC02 e TC03) clones and one Corymbia citriodora x C. torelliana (CT01) clone were collected, disinfested and inoculated in JADS culture medium, in order to compare the effects of light quality from a dark/fluorescent lamp, a fluorescent lamp, and white and red/blue LEDs. At 30 days after inoculation, the following characteristics were evaluated: average contamination percentage, oxidation, non-reactive explants, shoot length and average number of shoots per explant greater than 0.5 cm. Gathered data showed that the use of red/blue LED light source obtained the best results in all assessed characteristics in the in vitro introduction

Desinfestação e germinação in vitro de Lychnophora pohlii

Lychnophora pohlii Sch. Bip., espécie conhecida como arnica e usada na medicina popular, é fonte de princípios ativos com ação anti-inflamatória, analgésica e cicatrizante. No entanto, o conhecimento sobre os aspectos básicos da sua propagação é muito escasso. Assim, o objetivo deste trabalho foi estabelecer metodologias de desinfestação e germinação in vitro de L. pohlii. O primeiro teste consistiu na avaliação da imersão das cipselas em hipoclorito de sódio (2,5 e 5%) durante 5, 10, 15, 20 e 25 minutos. No segundo teste avaliou-se a desinfestação em ácido sulfúrico por 5, 10, 15, 20 e 25 minutos, e em hipoclorito de sódio 5% por 20 e 25 minutos acrescida ou não de etapa anterior de imersão em fungicida (1 gL-1) por 15 minutos. No terceiro teste fez-se a desinfestação em ácido sulfúrico durante 5 e 10 minutos, posteriormente inoculou-se as cipselas em meio de cultura contendo GA3 (0, 1, 2 e 4 mgL-1). Menor taxa de contaminação (63%) foi obtida com hipoclorito de sódio a 5% quando comparada à taxa de 83% na concentração de 2,5%, não havendo influência dos tempos de imersão. O ácido sulfúrico permitiu a obtenção das menores taxas de contaminação. Para a germinação, a imersão em ácido sulfúrico por 10 minutos foi mais eficiente (40%) quando comparada ao tempo de 5 minutos (31%), sendo desnecessário adicionar GA3 no meio. Assim, para estabelecimento de L. pohlii in vitro o tratamento das cipselas com ácido sulfúrico é mais adequado por permitir a desinfestação e aumentar a germinação

EFFECTS OF EXPLANT TYPE, CULTURE MEDIA AND PICLORAM AND DICAMBA GROWTH REGULATORS ON INDUCTION AND PROLIFERATION OF SOMATIC EMBRYOS IN EUCALYPTUS GRANDIS X E. UROPHYLLA1

ABSTRACT The objective of the present study was to test the effects of explant type, auxin concentrations, culture media, and auxin concentrations on the induction and proliferation of somatic embryos of Eucalyptus grandis x E. urophylla. Seeds and cotyledons were used as explants and inoculated in culture media containing 1.13, 2.26, 3.39 and 4.52 µM dicamba or 4.14, 10.35, 20.71 and 31.06 µM picloram. Embryogenic calli induced in the picloram treatments were used as explants and inoculated in semisolid or liquid media containing 4.14, 10.35, 20.71 and 31.06 µM picloram and keeping the origin of the embryogenic callus (seeds or cotyledons) and the concentration of picloram in those who were in the induction phase. Statistical, descriptive and anatomical analyses were performed. Induction of somatic pro-embryos into the juvenile plant material of Eucalyptus grandis x E. urophylla was performed using seeds or cotyledons as the source of explants, with the addition of dicamba and picloram as growth regulators. The use of cotyledons as a source of explants and the concentration of 4.1 µM picloram added to the culture media resulted in a higher induction of somatic pro-embryos. Proliferation of secondary somatic embryos was achieved using liquid medium added with picloram

Light quality in plant tissue culture: does it matter?

The primary issues regarding the lack of protocol reproducibility among laboratories are environmental factors. Light (quantity and particularly quality), is one of those main factors, and studies seldom present the spectral quality of the light sources used. With the advent of light-emitting diode (LED) technology, impressive progress has been made in environmental controls and morphogenetic responses, as directed by the light used in the culture shelves. A wide array of LED lights with different spectra are currently available and light is important in large-scale propagation, especially liquid bioreactor systems. LED technology continues to evolve rapidly and has created additional possibilities. This laboratory has dedicated extensive efforts to implement photoautotrophic propagation, and light is a key component of the system. This review presents relevant topics on the influence of light in various plant tissue culture-based techniques