Adriano Bortolotti da Silva

Sacarose e pH na germinação in vitro de grãos de pólen de citros

Objetivou-se avaliar o efeito da sacarose e pH na germinacao in vitro de graos de polen das cultivares Valencia, Natal e Pera. Para testar o efeito da sacarose, os graos de polen foram distribuidos uniformemente em placas de Petri contendo meio de cultura basico constituido de 10 gL-1 de agar, 800 mgL-1 de nitrato de calcio e 200 mgL-1 de acido borico, acrescido de sacarose (0, 50, 100, 150 e 200 gL-1). Para verificacao do pH satisfatorio, os graos de polen foram inoculados em meio de cultura contendo 10 gL-1 de agar e 800 mgL-1 de nitrato de calcio, 200 mgL-1 de acido borico,100 gL-1 de sacarose e pH de 3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5. Apos inoculacao, os graos de polen foram incubados em BOD a 25oC por 12 horas. A porcentagem de germinacao foi obtida com auxilio de microscopio optico com objetiva de 10 X. Para todas as cultivares estudadas, a maior porcentagem de germinacao foi obtida com 100 gL-1 de sacarose e o maior numero de graos de polen germinados foi verificado em pH 6,5, sendo observado que maiores valores de pH aumentaram tambem a quantidade de polens estourados para as cultivares Natal e Pera e diminuiram para Valencia.

Efeito de substratos na aclimatização de mudas micropropagadas de abacaxizeiro cv. Pérola

Objetivou-se com este trabalho verificar o efeito da materia orgânica como componente de substratos para mudas micropropagadas de abacaxizeiro cv. Perola em fase de aclimatizacao. Mudas micropropagadas de abacaxizeiro cv. Perola, selecionadas de acordo com o peso (aproximadamente 2 g), foram plantadas em bandejas de isopor de 72 celulas de 120 cm3 contendo proporcoes de substratos com terra, esterco bovino, Plantmax e materia orgânica. O delineamento estatistico utilizado foi o inteiramente casualizado com 4 repeticoes e 3 plantas por parcela. As avaliacoes foram feitas 90 dias apos o plantio, quando se avaliou: altura da planta, comprimento de raiz, peso de materia fresca de raiz e parte aerea, peso de materia seca de raiz e parte aerea e numero de folhas. Com os resultados obtidos, conclui-se que a materia orgânica tem efeito significativo no desenvolvimento das mudas. Com o substrato contendo terra, esterco e Plantmax foi obtido o melhor desenvolvimento das raizes e parte aerea.

BAP e substratos na aclimatização de plântulas de gloxínia (Sinningia speciosa Lood. Hiern.) provenientes de cultura de tecidos

The present work aimed to evaluate the influence of concentrations of 6-benzylaminopurine (BAP) used in acclimatization of gloxinia (Sinningia speciosa Lood. Hiern). Concentrations of BAP (0.0; 0.5; 1.0 and 2.0 mg L-1) in vitro and substrates (vermiculite, plantmax®, and vermiculite+plantmax®) were tested for acclimatization in every possible combination. After in vitro inoculation, the material was transferred to a growth chamber with temperature of 26±1oC and light intensity of 35 m mol m-2 s-1 for 16 hours, remaining under these conditions for 60 days. After that period, the plants obtained were transferred to pots containing substrates in a greenhouse. The evaluations were performed 120 days after cultivation. It were measured number of shoots, roots dry weight, above-ground dry weight, and number of flowers. On acclimatization, the best results for the variables were obtained with the use of the substrate Plantmax® or Plantmax®+vermiculite for plants originated from culture tissue.

In vitro rooting of an apple rootstock in several substrates

The traditional process for production of apple rootstocks presents low efficiency. The tissue culture techniques have been a viable alternative, because they allow to increase the multiplication process, they avoid dissemination of diseases and maintains the plant mothers characteristics. The objective of this work is identify a substitute for agar in the growth media for the rooting of apple (Malus domestica Borkh.) rootstock, cultivar M-7. The experimental design was completely randomized, in a 5x4 factorial scheme, with 4 replications and 4 explants per plot. The salt concentrations of the medium MS were 0%, 50%, 100%, 150% and 200 %. The substrates were agar, vermiculite and sand, in all possible combinations. The MS medium was placed into flask and autoclaved at 121oC for 20 minutes. The growth medium was supplied with 1.0 mg L-1 IBA. The evaluations were monitored through the following parameters: shoot height, dry weight and fresh weight matter of shoot and root system. The best growth shoots and root systems are obtained with the use of agar 3.0 and 6.0 g L-1, regardless of the salt concentrations. The use of sand gave similar results as compared to agar, when the salts concentration was 100% of the MS medium.

Cattleya walkeriana growth in different micropropagation systems

The aim of the present research was to verify the in vitro growth of orchids in different systems of micropropagation, being cultivated in a bioreactor, with natural ventilation and conventional systems. Cattleya walkeriana plants were obtained from the germination of seeds in culture medium. After 8 months, seedlings with 1 cm of length were placed in a culture vessel according to the treatments, which counted with two micropropagation systems (conventional and natural ventilation) in three media of culture (liquid, solid with 5 or 6g L-1 of agar). Two additional treatments in bioreactor of temporary and continuous immersion were performed. The design was entirely randomized (ERD), consisting of a 2x3 factorial with two additional treatments, totaling 8 treatments with three repetitions. The temporary immersion bioreactor promoted a bigger growth of the aerial part and of the root system, bigger accumulation of dry mass and better control of water loss by the plants. The temporary immersion bioreactor is the best micropropagation system for the C. walkeriana growth in vitro.

Multiplicação in vitro de copo-de-leite: espectros de luz e sacarose

Light spectrum can modify plant morphogenesis through a number of processes mediated by light receptors, mainly in the red and blue region. The aim of this work was to determine a possible light type more active than the white light, and an optimized sucrose concentration, in order to increase the efficiency of the calla lily in vitro multiplication . To that end, the treatments consisted of four different light types (white, red, blue and green), under which the explants grew, supplied by colored T8 20W Ecolume 05/1 fluorescent lamps and various sucrose concentrations (0; 15; 30; 45 and 60g L-1). The culture medium contained MS salts and vitamins, added of 5mg L-1 BAP and 5.5g L-1 agar. The light type did not influence in vitro propagation of calla lily and there were a higher number of sprouts (2.0) in 45g L-1 of sucrose. There was higher number of leaves in white (3.8) and in blue light (2.9) with 15 and 60g L-1 of sucrose, respectively. Higher length of sprouts (3.7cm) was observed in 60g L-1 of sucrose and higher fresh weight of the aerial part (1.07g) in 60g L-1 of sucrose.

Modelo matemático para previsão da produtividade do cafeeiro

The objective of this work was to create a practical and effective mathematical model for the early prediction of crops based on some phenological attributes of the plant: height, number of fruits in the 4th and 5th internodes of the plagiotropic branches, length in meters of the planted coffee row and diameter measured at the lower region of the coffee plants. The experiment was carried out in the coffee plantations of IFSULDEMINAS - campus Machado - where the productivity of four cultivars of different sizes were analysed during the 2010-2011 season: Catucai, Mundo Novo, Ruby and Topaz. Each of these was an experimental unit, from which 10 plants were randomly chosen. Of these, 6 branches of each plant were sampled (three on the side of the rising sun, and three on the side of the sunset; two in the upper third, and two in the middle region, and two in the lower region of each plant). Data were collected at the end of February 2011. The model which considers the proportion of the coffee plant canopy in order to get closer to the real architecture of the plant was the most significant, with a coefficient of determination of 0.83.

Calogênese in vitro em anteras de coffea arabica L.

O cafe e um dos mais importantes produtos do mercado internacional; porem, o tempo gasto e os recursos despendidos sao fatores limitantes para o melhoramento do cafeeiro por meio de metodos convencionais. Contudo, a cultura de anteras surge como uma alternativa viavel e de curto prazo para solucao desses problemas. Com o presente trabalho, objetivou-se a producao de dihaploides com a cultura de anteras do cafeeiro (androgenese indireta), buscando um protocolo para a fase de inducao de calos. Para tanto, foi efetuada a assepsia dos botoes florais e das anteras, que, em seguida, foram inoculadas em meio IC e mantidas no escuro por 8 semanas, sob temperatura de 25oC ± 1. Para induzir a calogenese em anteras da cv. Acaia Cerrado, foram testadas as concentracoes de 2,4-D (0, 1, 2 e 4 mg.L-1) x cinetina (0, 2, 4 e 8 mg.L-1) e 2,4-D (0; 0,5; 1 e 2 mg.L-1) x AIB (0; 0,5; 1 e 2 mg.L-1) mais 2iP (2 mg.L-1) e, para a cv. Rubi, as concentracoes de 2,4-D (0, 1, 2 e 4 mg.L-1) x cinetina (0, 2, 4 e 8 mg.L-1). Foi observado que a maior porcentagem de inducao de calogenese em anteras na cv. Acaia Cerrado ocorre com as combinacoes de 2,4-D (2 mg.L-1) + cinetina (1,9 mg.L-1) e 2,4-D (0,86 mg.L-1) + AIB (1 mg.L-1)+ 2iP (2 mg.L-1); para cv. Rubi, a combinacao de 2,4-D (1,9 mg.L-1) e cinetina (4 mg.L-1).

GROWTH AND PHYSIOLOGICAL RESPONSES OF TREE SPECIES (Hymenaea courbaril L., Peltophorum dubium (Spreng.) Taub. and Myroxylon peruiferum L. F.) EXPOSED TO DIFFERENT COPPER CONCENTRATIONS IN THE SOIL

1 Received on 13.06.2017 accepted for publication on 01.03.2018. 2 Universidade Federal de Lavras, Programa de Pós-Graduação em Botânica Aplicada, Lavras, MG-Brasil. E-mail: <danimarques.bio@gmail.com>. 3 Universidade José do Rosário Vellano, Instituto de Ciências Agrárias, Alfenas, MG-Brasil. E-mail: <adriano.silva@unifenas.br>, <jose.mantovani@unifenas.br> and <DalvanaSousa@hotmail.com>. 4 Universidade Federal de Alfenas, Instituto de Ciências da Natureza, Alfenas, MG-Brasil. E-mail: <thiagonepre@hotmail.com>. *Corresponding author.

EARLY GROWTH OF COFFEE PLANTS AND SOIL FERTILITY PROPERTIES IN RESPONSE TO COFFEE HUSK APPLICATION

Coffee processing generates large amounts of husk, which can be used as organic fertilizer if technical criteria are considered. This study investigated the effect of coffee husk, applied to or incorporated into the soil, on soil fertility properties, early crop growth and nutrient accumulation in coffee plants. The experiment analyzed coffee plants in a greenhouse in pots, in randomized blocks, in a 5x2 factorial arrangement plus a control treatment, with four replicates. The treatments consisted of the combination of five coffee husk rates (3.5; 7; 14; 28, and 56 t ha -1 ), applied in two forms: spread on the surface or incorporated into the soil, plus the control treatment, without husk application. Portions of 7 dm 3 soil were blended with lime, phosphate fertilizer, as well as coffee husk rates in the treatments with residue incorporation, and incubated for 30 days. Thereafter, one coffee seedling per plot was planted, the coffee husk rates were applied on the soil surface for the treatments without residue incorporation, and the plants were left to grow for 180 days. Coffee husk applied to or incorporated into the soil surface increases the K and organic matter contents of the soil, intensifies the early growth of coffee plants and accelerates N and K accumulation in the plant shoots. The application of coffee husk on the surface is more indicated than its incorporation into the soil, and the best rate at coffee planting is equivalent to 20 t ha -1 .