Responses of Panicum and Brachiaria to irrigation during winter in the Goiás’ Cerrado-Brazil

Forage production in the Cerrado is based on well-defined seasons: a rainy summer, and a dry winter. To define strategies that minimize the seasonality of forage production, responses in growth and biomass accumulation of five irrigated forages were evaluated during winter. The experimental design was randomized blocks, in a split plot arrangement, with five replicates, five forages in the plots (three of Panicum maximum - Mombasa, Tanzania, and Masai; two of Brachiaria brizantha - piatã and MG5), and five cuts in the subplots made from July to October 2016. Forages were cultivated with centre-pivot irrigation and the water level was defined according to the reference evapotranspiration determined through a Class A pan evaporation method, 0.8 kc, and two-day irrigation shifts. The number of shoots, leaves/tiller, leaves/plant, fresh leaf and stem biomass, dry leaf and stem biomass, fresh leaf mass/fresh stem mass ratio, dry leaf mass/dry stem mass ratio, and biomass accumulated in the five cuts were calculated. Irrigated forage during winter in the Goiás’ Cerrado showed satisfactory growth, reaching a lower plant height between cuts than those reported in the literature. Among the Panicum grasses, Mombasa grass stood out, and MG was superior to piatã grass. Highlights The forages Panicum maximum - Mombasa, Tanzania, and Masai -; and Brachiaria brizantha - piatã and MG5 -, presented satisfactory responses in growth and biomass accumulation in an irrigated culture during winter in the Goiás’ Cerrado. The Mombasa grass stood out among the forage of the genus Panicum and MG5 in the Brachiaria. The Mombasa and Brachiaria MG5 grasses are recommended for cultivation of irrigated forage during the winter in the Goiás’ Cerrado.Forage production in the Cerrado is based on well-defined seasons: a rainy summer, and a dry winter. To define strategies that minimize the seasonality of forage production, responses in growth and biomass accumulation of five irrigated forages were evaluated during winter. The experimental design was randomized blocks, in a split plot arrangement, with five replicates, five forages in the plots (three of Panicum maximum - Mombasa, Tanzania, and Masai; two of Brachiaria brizantha - piatã and MG5), and five cuts in the subplots made from July to October 2016. Forages were cultivated with centre-pivot irrigation and the water level was defined according to the reference evapotranspiration determined through a Class A pan evaporation method, 0.8 kc, and two-day irrigation shifts. The number of shoots, leaves/tiller, leaves/plant, fresh leaf and stem biomass, dry leaf and stem biomass, fresh leaf mass/fresh stem mass ratio, dry leaf mass/dry stem mass ratio, and biomass accumulated in the five cuts were calculated. Irrigated forage during winter in the Goiás’ Cerrado showed satisfactory growth, reaching a lower plant height between cuts than those reported in the literature. Among the Panicum grasses, Mombasa grass stood out, and MG was superior to piatã grass. Highlights The forages Panicum maximum - Mombasa, Tanzania, and Masai -; and Brachiaria brizantha - piatã and MG5 -, presented satisfactory responses in growth and biomass accumulation in an irrigated culture during winter in the Goiás’ Cerrado. The Mombasa grass stood out among the forage of the genus Panicum and MG5 in the Brachiaria. The Mombasa and Brachiaria MG5 grasses are recommended for cultivation of irrigated forage during the winter in the Goiás’ Cerrado

Quantitative immunochemistry using IgG and IgY against plant hormones

The present study focuses on obtaining and comparing IgY and IgG antibodies against indoleacetic acid (IAA), zeatin (Z) and isopentenyladenine (2iP). The use of antibodies in rapid tests to analyse hormones has been developed for the immediate application of high sensitivity immunoglobulins against IAA, 2iP and Z. Each plant hormone was conjugated to bovine serum albumin (BSA) or ovalbumin (OVA), both of animal origin, using chemical couplings to their respective functional groups. The IAA, Z and 2iP antibodies were then produced from chicken egg yolks (IgY) or from rabbit serum (IgG) that had been hyperimmunised with the respective conjugated protein. The antibodies were obtained from rabbit sera or chicken egg yolks, purified by ammonium sulphate precipitation and subsequently used in indirect analytical immunoassays (competitive enzyme-linked immunosorbent assay; ELISA) to detect and quantify these hormone molecules. During titration, differences were observed not only between the specific antibody sources but also between the different conjugated hormones obtained. Although, the IgGs failed to produce a competitive IAA detection system, the IgY antibodies proved to be suitable for quantifying the plant hormones. The immunoenzymatic assay using IgY achieved a detection limit of 3.4 nmoles (3.4 ppb) for zeatin, 6 pmoles (6 ppt) for 2iP and 480 pmoles (480 ppt) for IAA, whereas the IgG detection limits established were in micromolar (ppm) range and manifested varying results and low specificity near the limit of detection. Comparisons and discussions are presented on the impact of the hormone-protein conjugates and the potential use of antibodies in analysing zeatin and 2iP. The antibody characteristics, the presence of antibody interference in the samples and the limitations and advantages of immunochemical assays are also discussed.Keywords: Quantification, auxin, cytokinins, antibodiesAfrican Journal of Biotechnology Vol. 12(24), pp. 3828-383

Crescimento de cafeeiros irrigados no Cerrado/ Growth of irrigated coffee makers in the Cerrado

O Cerrado brasileiro possui grande potencial devido suas condições edafoclimáticas. Objetivou-se avaliar, o comportamento de genótipos de café, quanto ao desenvolvimento fenológico nas condições climáticas de Ceres – GO. O experimento foi implantado no IF Goiano – Campus Ceres, contendo 31 cultivares e 4 progênies avançadas. O delineamento foi em blocos casualizado com quatro repetições, e parcelas formadas por 10 plantas. Avaliou-se o crescimento aos 30 e 36 meses após o plantio (MAP), mensurando a altura da planta, diâmetro de copa, comprimento do segundo par de ramos plagiotrópicos, diâmetro do caule, número de nós do ramo ortotrópico e do segundo par de ramos plagiotrópicos. Os dados foram submetidos à ANOVA, testes de médias dos parâmetros fenológicos comparadas pelo teste Scott-Knott, a 5% de probabilidade. O genótipo Catucaí Amarelo 2SL apresentou maior taxa de crescimento para todas as variáveis aos 36 MAP

Competitive-IgY- Enzyme Linked Immuno Sorbent Assay (CIgY-ELISA) to detect the cytokinins in Gerbera jamesonii plantlets

A competitive hyper-immune yolk Immunoglobulin Y - Enzyme Linked Immune Sorbent Assay (CIgY-ELISA), was developed as an alternative method to detect zeatin and 2ip in plantlets of gerbera. The endogenous level of hormones in the plantlets in vitro of gerbera with one or six weeks after replication was determined with competitive IgY-ELISA set to detect between 1 and 100 pmoles of plant hormone for each 1.0 g tissue. The plantlets of six weeks presented sprouts and root, while the plantlets of one week presented only sprouts. The CIgY-ELISA was set with high independent variables values of sensitivity/specificity of 96/89 % for zeatin and 94/78 % for 2ip, with high values of reproducibility (up to 90 %) for both the cytokinins. Zeatin content varied from 2.2 to 2.8 pmoles.g-1 and from 2.7 to 3.3 pmoles.g-1 on the plantlet with one and six weeks, respectively. The 2ip content did not vary and was detected near the detection limit in all the assays. It was concluded that the observed capabilities of CIgY-ELISA were putative and the competitive assay was a highly robust and stable method, which could be used for the studies on plant physiology for endogenous cytokinins

Growth of Brachiaria decumbens in Latosol contaminated with copper

ABSTRACT Brachiaria decumbens presents high rusticity, rapid growth, as well as easy implantation and management. The aim of the study is to evaluate the growth of brachiaria in soil contaminated with copper. An experiment following a 3 x 4 factorial design was carried. It comprised three plant ages (30, 45 and 60 days after transplanting) and four copper concentrations (0, 20, 40 and 80 mg of Cu per kg of soil). Plant age and copper concentrations have influenced the main pseudostem length, the number of leaves, as well as the leaf area, chlorophyll (SPAD), fresh and dry shoot matter, root system volume, and fresh and dry root system matter of plants. The lowest dry shoot matter accumulation was found at the concentration 51.24 mg Kg-1. The herein investigated copper concentrations have influenced the growth of Brachiaria decumbens. The lowest growth variable values were between 45.52 and 57.63 mg.Kg-1. Thus, brachiaria has shown potential to be used in Copper phytoremediation at concentrations below 45.52 mg Kg-1

Efeito da luz e diferentes concentrações de sais do meio MS na regeneração in vitro de Catharanthus roseus.

A regeneração in vitro de Catharanthus roseus, a partir de explantes caulinares, predomina de forma direta, ocorrendo o desenvolvimento de brotos a partir das gemas presentes. No entanto, no caso das plantas medicinais há um grande interesse na obtenção de calos para a extração de princípios ativos, uma vez que na maioria das vezes obtém maior rendimento. O presente trabalho tem por objetivo avaliar o efeito da luz e da concentração de sais na regeneração in vitro de explantes caulinares de Catharanthus roseus. O experimento foi conduzido no LCTV do DFITO-IA-UFRRJ. Adotou-se o delineamento de blocos ao acaso, em esquema fatorial 2 x 4, sendo dois tratamentos com luz (ausência ou fotoperíodo com 16 horas luz e 8 h de escuro), quatro concentrações dos sais do meio MS (25; 50; 75 e 100%) e quatro repetições. Seis semanas após a implantação do experimento, avaliou-se a sobrevivência dos explantes (%), a brotação (%), a formação de calo (%), a diferenciação de raízes (%), o número e comprimento (cm) dos brotos formados, o comprimento e a massas fresca e seca  dos calos. Todos os tratamentos apresentaram condições favoráveis para a sobrevivência dos explantes. Na ausência de luz, independente das concentrações dos sais, somente ocorreu regeneração de forma indireta, e a partir dos calos formados surgiram raízes adventícias e algumas brotações. Já na presença de luz, houve a proliferação de brotos a partir das gemas existentes nos explantes e os calos formaram apenas nas bases dos explantes. Enquanto na ausência de luz houve a formação de calos friáveis, com coloração clara (creme), na presença de luz formou calos esverdeados e compactos. A interação da luz com a concentração dos sais foi significativa para a formação de calo, para o comprimento dos brotos e o comprimento e massa dos calos. Na ausência de luz não houve diferença entre as concentrações dos sais para a formação de calo, enquanto no fotoperíodo de  16 horas luz e 8 h de escuro a concentração de 100% dos sais apresentou menor valor

Effects of auxin and misting on the rooting of herbaceous and hardwood cuttings from the fig tree Efeitos de auxina e nebulização no enraizamento de estacas herbáceas e lenhosas de figueira

Propagation of the fig tree predominately uses hardwood cuttings obtained from pruning stock plants. With a view to optimising fig tree propagation, the effects of auxin and misting on the rooting of herbaceous and hardwood cuttings from the fig tree were evaluated. An experiment was set up in a 2x2x2 factorial design, with two types of cuttings (softwood and hardwood), two levels of auxin (0 and 1000 mg L-1 indolbutyric acid) and two environments (with and without misting). Thirty days after starting the experiment, rooting, root length, sprouting and losses were all evaluated. The interaction of the type of cutting and the auxin was significant for rooting, sprouting, root length and cutting loss. Misting did not affect the variables analysed. In the absence of auxin, there was no difference between the type of cutting for rooting, length of root and sprouting, while the application of auxin (1,000 mg L-1) produced a reduction in these variables. The production of fig tree seedlings can be made from either softwood or hardwood cuttings and does not require the use of auxin or misting.<br>A propagação da figueira predomina com o uso de estacas lenhosas obtidas após a poda de plantas matrizes. Visando otimizar a propagação da figueira, avaliou-se os efeitos da auxina e da nebulização no enraizamento de estacas herbáceas e lenhosas de figueira. Foi implantado um experimento em fatorial 2x2x2, sendo dois tipos de estacas (herbáceas e lenhosas), dois níveis de auxina (0 e 1.000 mg L-1 de ácido indolbultírico) e dois ambientes (com ou sem nebulização). Aos 30 dias após a implantação do experimento, avaliou-se o enraizamento, comprimento da radícula, brotação e perdas. A interação do tipo de estaca e auxina foi significativa para enraizamento, brotação, comprimento da radícula e perdas de estacas. A nebulização não interferiu nas variáveis analisadas. Na ausência de auxina não houve diferença entre os tipos de estacas para o enraizamento, comprimento da radícula e brotação, enquanto, a aplicação de auxina (1.000 mg L-1) proporcionou redução para estas variáveis. A produção de mudas de figueira pode ser realizada a partir de estacas herbáceas ou lenhosas e dispensa o uso de auxina e nebulização