Concentrações de silício e GA3 na propagação in vitro de orquídea em condição de luz natural

A little information about the application of silicon in orchids (in vitro/ex vitro) justified the present work that objectified to evaluate silicon concentrations (Si) and giberelic acid (GA3) on characteristics of growth and in vitro multiplication. Cattleya loddigesii orchid plants deriving of seeds produzing for self-fertilization and in vitro germinated had been submitted to the uniformization, in culture medium KC modified, during three months. After this period, each bottle with approximately four plants of 1.0 cm length and 15mL of culture medium KC; increased of 2 g L-1 of activated charcoal and sodium silicate (0, 5, 10 and 15 mg L-1) and GA3 (0, 5, 10 and 15 mg L-1) in all possible combinations. The pH was adjusted for 5.8 ± 0.1 and made solid with 5 g L-1 of agar before the sterilization process at 121ºC and 1 atm per 20 minutes. The culture medium has been kept in growth room with irradiance around 99,43W.m-1 and temperature of 28±1ºC measured in the period March to June, 2008. The experimental delineation entirely was casualisated with 5 repetitions and 20 plants for treatment. After 120 days was evaluated the number of leaf, sprouts, roots, length of roots and the aerial part. Better results in vitro propagation of Cattleya loddigesii under natural light had been verified with 0-10 mg L-1 of GA3 associated with 0-5 mg L-1 of sodium silicate.O presente trabalho teve como objetivo avaliar concentrações de Si e GA3 sobre as características de crescimento e multiplicação de orquídea sob luz natural. Plântulas de Cattleya loddigesii, oriundas de sementes produzidas por autofecundação e germinadas         in vitro, foram submetidas à uniformização, em meio de cultura KC modificado, durante três meses. Cada frasco conteve quatro plântulas de aproximadamente 1,0 cm de comprimento (explante) e 15 mL de meio de cultura KC; acrescido 2 g L-1 de carvão ativado. Os tratamentos consistiram de combinações de silicato de sódio (0, 5, 10 e 15 mg L-1) e GA3 (0, 5, 10 e 15 mg L-1). O meio de cultura teve seu pH ajustado para 5,8 ± 0,1 e solidificado com  5 g L-1 de ágar antes do processo de autoclavagem. As culturas foram mantidas em casa de vegetação. O delineamento experimental foi inteiramente casualizado, com 5 repetições e     20 explantes por tratamento. Ao final de 120 dias foram avaliados número de folhas, número de brotos, número de raízes, comprimento médio de raízes e da parte aérea. O cultivo in vitro de C. loddigesii sob luz natural dependeu das concentrações de silicato de sódio e GA3, sendo que os melhores resultados foram verificados com 0-10 mg L-1 de GA3 associada a 0-5 mg L-1 de silicato de sódio. &nbsp

Correlation between morphological characters and estimated bunch weight of the Tropical banana cultivar

The objective of this study was to measure and identify the variables that have more influence on bunch weight (BW), and determine a statistical model for predicting yield for the Tropical banana cultivar (cv.). The experiment consisted of a uniformity trial, conducted in Guanambi, Bahia, with a total of 360 plants of the Tropical cultivar YB42-21 (AAAB) in an area of 2,160 m2. The vegetative characteristics such as plant height, pseudostem circumference, number of children (suckers) produced and number of green leaves at flowering and harvest, and yield characteristics such as BW, number of hands and fruits, weight of the second hand, length and diameter of the fruit were assessed in two growing seasons. In the evaluation, each plant was considered as a basic unit with an area of 6 m2, thus, there was a total of 360 basic units. The variables that correlated with the weight of the bunch are: average fruit weight (FW), weight of the rachis, number of fruits per bunch, fruit length (FL) and number of leaves at harvest. The methodology of multiple linear regression (MLR) was used to estimate bunch weight. The most significant variables that were measured included number of leaves at harvest, number of fruits per bunch, FW, FL, rachis weight (RW) and stalk length (SL), generating the following prediction equation: BW= -5.249 + 0.11NLH + 0.066NFB + 0.046FW + 0.183FL + 2.039RW -0.011LS.Key words: Musa spp., production, banana, regression model

Modificações morfoanatômicas e fisiológicas de maracujazeiro fertilizado com silício

The objective of this work was to evaluate the effect of silicon fertilization on gas exchange, leaf anatomy, and ultrastructural characteristics of passion fruit (Passiflora edulis). The treatments comprised four concentrations of silicon (0, 0.28, 0.55, and 0.83 g per pot) at 1% silicic acid solution (SiO2.XH2O). This solution was applied around the stems of the plants. The first application was made 15 days after seedlings were transplanted. In total, three applications were made at 15-day intervals. The pots that constituted the control treatment received water in the same amount. After the final application, the plants were subjected to analyses of gas exchange, anatomical changes, and ultrastructural characteristics. The use of silicon promotes anatomical changes in passion fruit seedlings, such as increased adaxial epidermis thickness, reduced palisade parenchyma, and increased polar diameter/equatorial diameter ratio, which is related to stomata functionality. The concentrations of 0.55 and 0.83 g silicon per pot provide higher rates of photosynthesis, of transpiration, and stomatal conductance. The concentration of 0.83 g silicon per pot results in the greatest deposition of silicon in the abaxial epidermis of leaf surface.O objetivo deste trabalho foi avaliar o efeito da adubação silicatada nas trocas gasosas, na anatomia foliar e nas características ultraestruturais de maracujazeiro (Passiflora edulis). Os tratamentos consistiram em quatro concentrações (0, 0,28, 0,55, e 0,83 g por vaso) de silício, na forma de solução de ácido silícico (SiO2.XH2O) a 1%. Esta solução foi aplicada ao redor do caule das plantas. A primeira aplicação foi realizada 15 dias após o transplantio das mudas. No total, foram realizadas três aplicações, em intervalos de 15 dias. Os vasos que constituíram o controle (testemunha) receberam água na mesma quantidade. Após a última aplicação, as plantas foram submetidas a análises de trocas gasosas, alterações anatômicas e características ultraestruturais. O uso de silício promove mudanças anatômicas em mudas de maracujazeiro, como o aumento da espessura da epiderme adaxial, a redução do parênquima paliçádico e a maior relação diâmetro polar/diâmetro equatorial, que está relacionada à funcionalidade dos estômatos. As concentrações de 0,55 e 0,83 g de silício por vaso proporcionam maiores taxas fotossintéticas, de transpiração e de condutância estomática das mudas de maracujazeiro. A concentração de 0,83 g de silício por vaso proporciona maior deposição de silício na epiderme abaxial da superfície foliar

productive and qualitative parameters of four physalis species cultivated under colored shade nets

Abstract The genus Physalis L. has great importance in the framework of Brazilian biodiversity especially in the Amazon region. The use of colored shading nets allow manipulating the light spectrum, and thus supplying the appropriate quantity and quality of light for each species and maximizing production. The purpose of this study was to evaluate the effects of shade nets on fruit production and qualitative parameters of four species belonging to genus Physalis. The experimental design was random blocks with a 4 x 5 factorial scheme, four species of Physalis (P. peruviana, P. pubescens, P. minima and P. ixocarpa) and four colors of shade nets (white, blue, red and black), besides the control treatment under full sun exposure. Fruits were collected weekly and evaluated for longitudinal and transversal diameter and biomass with and without a calyx. Finally the percentage of calyx biomass compared to the total fruit biomass, number of fruits per plant and production were determined. A differentiated response was found among the species regarding the coloring of the converter shade nets. Plants of P. peruviana had the best productive and qualitative parameters of fruits when cultivated in full sunlight or under white shade nets, P. pubescens and P. minima when cultivated in full sunlight or under white and blue shade nets, and P. ixocarpa under red or black shade nets

Conservação in vitro de físalis por meio do cultivo de segmentos nodais em crescimento lento

The objective of this work was to evaluate the effects of temperature and osmotic agents on the in vitro conservation of Cape gooseberry (Physalis peruviana). Temperatures at 18 and 25°C, as well as the osmotic agents sucrose, mannitol, and sorbitol were tested. A short-term in vitro conservation of Cape gooseberry can be achieved at 18°C, using 30 g L-1 sucrose.O objetivo deste trabalho foi avaliar os efeitos da temperatura e de agentes osmóticos na conservação in vitro de físalis (Physalis peruviana). Foram testadas as temperaturas de 18 e 25°C, bem como os agentes osmóticos sacarose, manitol e sorbitol. A conservação de físalis in vitro, em curto prazo, pode ser conseguida a 18°C, em meio com adição de 30 g L-1 de sacarose

Challenges of organic agriculture for the production of composts and vermicompost for the production of medicinal plants – A socioeconomic demand

Although the demand for organic fertilizers in agriculture is growing, it remains incipient in some production sectors, such as medicinal plant production, which does not possess specific technology for its development. Solid residues are highly contaminant to water sources, soil, populations and biodiversity but can potentially be used to produce organic composts and vermicompost, such production not only enables nutrient recycling but also acts on soil conditioning, increasing soil organic matter and improving its physical, chemical and biological characteristics, as well as strengthening organic production with an emphasis on medicinal plant production. In this context, recommendations for and applications of organic fertilizers available in the market were reviewed; in addition, the imminent socioeconomic demand for organic compost and vermicompost production was contextualized based on residues from coffee and sugarcane production and cattle farming for application to the medicinal plant production chain. It is concluded that although these sectors produce a considerable amount of residues, they are not being reused in formulation of organic composts and vermicompost, and commercial organic fertilizers recommended for medicinal plant production were not found. Thus, the formulation of vermicomposting and composting from the reuse of agricultural residues, are potential social, economic technologies and tools to be valued and disseminated to traditional and family farmers

Effect of light and sucrose on photoautotrophic and photomixotrophic micropropagation of Physalis angulata

The biotechnological interest in genus Physalis has increased in the last decades, however, there are still few micropropagation studies of this genus. The objective of this study was to evaluate P. angulata photoautotrophic and photomixotrophic micropropagation with gas exchange under seven light spectra and five concentrations of sucrose. Lighting were yellow, blue, white, red, green, red + blue LEDs and natural light filtered by mesh. Sucrose concentrations were 0, 7.5, 15, 22.5 and 30 g.L-1. Phytotechnical, anatomical features and photopigment contents were evaluated through stem and root segment length, leaf number, leaf area, chlorophyll a and b contents, carotenoids, adaxial epidermis, palisadic and spongy parenchyma and abaxial epidermis. The data were compared by Scott-Knott's mean test and principal components analysis using the R software. Comparing the variables within lighting types, it was observed that only the screen treatment, screen-filtered natural illumination, obtained assessment in all variables. Comparing the levels of sucrose, it was observed that the treatment 15 g.L-1 sucrose obtained the highest number of averages with maximum evaluation. It was concluded that the natural light filtered by screen with 50% of shading allowed the photoautotrophic micropropagation of P. angulata. Better development results were observed in photomixotrophic micropropagation with 15 g.L-1 of sucrose