Joyce Dória Rodrigues Soares

Concentrações de sais do meio Knudson C e de ácido giberélico no crescimento in vitro de plântulas de orquídea

The aim of this research was to test different concentrations of culture medium Knudson C and gibberellic acid in the in vitro growth of Hadrolaelia lobatta x Hadrolaelia purpurata Aco and Cattleya loddigesii plantlets. Seedlings deriving from in vitro germinated seeds with approximately 1,0cm length, were inoculated in bottles of 250cm3 containing 60mL of Knudson C culture medium at salts concentrations of 0; 50; 100 e 200%, and supplemented with 0; 2.5; 5; 7.5; 10mg L-1 of GA3. The cultures were maintained in growth room with a 35µmolm-2s-1 irradiance, 16 hours photoperiod and 25±1°C of temperature. After 90 days, it is observed that the culture medium Knudson C 200% for Cattleya loddigesii promote better in vitro growth. The addition of GA3 (2.5mg L-1) is efficient in the number of leaves increment. Better in vitro multiplication is registered in Knudson C medium in the original concentration (100%). For Hadrolaelia lobatta x Hadrolaelia purpurata Aco, the concentration of Knudson C culture medium influences the number of leaves (salts 200%) and sprouts (salts 50%), but does not have effect in the growth and biomass. No effect of the GA3 in number of sprouts, length of aerial part and fresh mass for the two genotypes was verified.

Colchicine and amiprophos-methyl (APM) in polyploidy induction in banana plant

The objective was to assess the colchicine and amiprophos-methyl (APM) concentration and exposure period in the chromosome duplication of breed banana plants diploids. Banana stem tips were used from the following genotypes: breed diploids (1304-04 [Malaccensis x Madang (Musa acuminata spp. banksii)] and 8694-15 [0337-02 (Calcutta x Galeo) x SH32-63]). Colchicine was used at concentrations of 0 (control treatment), 1.25, 2.5 and 5.0 mM, while APM was used at 0 (control treatment), 40 and 80 μM, in solution under agitation (20 rpm), for 24 and 48 h periods. With the use of APM, 66.67% tetraploid plants were obtained in the 1304-04 genotype using 40 μM for 24 h and 18.18% in 80 μM for 48 h, while in the 8694-15 genotype using 40 and 80 μM colchicine for 48 h, 27.27 and 21.43% tetraploid plants were observed, respectively. For colchicine, in the 1304-04 genotype, only the 1.25 mM treatment for 48 h presented 25% tetraploid plants and in the 8694-15 genotype, the 5.0 mM concentration for 48 h produced 50% tetraploid plants. APM for 24 h enabled the tetraploid plant of the 1304-04 genotype to be obtained, while colchicine for 48 h resulted in tetraploid plants in the 8694-15 genotype. Key words : Musa acuminata, antimitotic, flow cytometry, tissue culture.

Adubação com silício via foliar na aclimatização de um híbrido de orquídea

Silicon types and concentration and their interactive effects on plantlet growth of orchid Hadrolaelia lobatta x Hadrolaelia purpurata were studied. The plantlets from in vitro seeds were maintained in greenhouse, with 70% brightness, in plastic pots (90 cm3) filled with charred peel rice. The plantlets were grown on silicon sources concentrations (0; 0.5; 1.0; and 2.0 mg L-1): sodium silicate (SS) and Supa Potassio® (SP) through foliar sprayings, in all possible combinations. After 8 months the transplant the leaves number, aerial part length, root number, largest root length, root fresh and dry mass were evaluated. With increase in sodium silicate concentrations, a decrease up to a certain point was verified for all the studied variables. Better results for development of orchid plants were verified in the absence of silicon sources.

Silicon sources in the micropropagation of the Cattleya group orchid

The purpose of this study was to determine the silicon source that provides better growth of Cattleya loddigesii orchid plants. Seedlings from seeds germinated in vitro with approximately 1.0 cm in length were inoculated in tubes containing 15 mL of modified Knudson C culture medium, added with sodium silicate (0, 5, 10 and 20 mg L -1 ) and potassium silicate (0, 5, 10 and 20 mL L -1 ), in all possible combinations. The culture medium had its pH adjusted to 5.8 ± 0.1 and solidified with 5 g L -1 of agar before the sterilization process at 121°C and 1 atm for 20 minutes. The cultures were maintained in a growth room with irradiance around 35 µmol m -2 s -1 , temperature of 25±1oC and photoperiod of 16 hours. The experimental design was completely randomized in a factorial scheme with 5 replications and 20 seedlings per treatment. Seedlings of C. loddigesii presented better growth (number of roots, length of the aerial part and of roots) in the modified Knudson C culture medium added with 5 mL L -1 of potassium silicate and 20 mg L -1 of sodium silicate. A larger number of shoots is observed with the addition of 5 mL L -1 potassium silicate in culture medium, in the absence of sodium silicate.

Light spectrum on the quality of fruits of physalis species in subtropical area

The aim of this study was to analyze the effect of colored-shade nets on the physicochemical characteristics of physalis in subtropical area. The experimental design was the randomized blocks with a 4 × 5 factorial, being four species of physalis (Physalis peruviana, P. pubescens, P. minima and P. ixocarpa) and four net colors (white, blue, red and black), besides the control under full sun. Titratable acidity (TA), pH, vitamin C, soluble solids (SS), SS/TA relation, total phenolics, anthocyanins and antioxidant capacity were evaluated. It was observed that P. peruviana and P. pubescens have more acid fruits, and P. minima shows vitamin C content higher than the other species. In general, fruits of P. peruviana and P. pubescens have better quality when grown in white, blue or black shade net; fruits of P. minima are physicochemically superior when produced under full sun or under white or blue shade net; finally, fruits of P. ixocarpa have low quality when produced under black net.

Tissue Culture Techniques for Native Amazonian Fruit Trees

In recent decades, the production of native fruits of the Amazon showed significant growth, mainly due to expansion of area for fruit production. It is noteworthy that this activity has had little impact on native vegetation, since most of the orchards were planted in areas previously occupied by other crops for market problems or environmental issues and pressure for sustainable agriculture, ceased to be interesting for farmers [4].

Flow Cytometry Applied in Tissue Culture

Flow cytometry is a powerful technology that allows for the simultaneous analysis of multiple attributes of cells or particles in a liquid medium. The first cytometer used was built during World War II, when [1] developed an equipment where particles flowed through the system to diffuse light through a lens, producing electrical signals sensed by a photodetector. The instrument could detect objects in the order of ~ 0.5 μm in diameter, and is recognized as the first flow cytometer used for observation of biological cells [2]. This would be possible to identify aerosols, bacteria that would possibly biological warfare agents as well as check the efficiency of gas mask filters against particles. In 1950, the same principle was applied to the detection and enumeration of blood cells. As hematology and cellular immunology, two biological areas, that drove the development of flow cytometry [3]. Later, with improved equipment and methods, this technique was adapted to other areas of biology, including the plant kingdom [4]. Already in 1973 the German botanist Friedrich Otto Heller used the Impulszytophotometrie (pulse cytophotometry in German). This scientist did not imagine that it has launched a new field of scientific research, which would later be called flow cytometry in plants.

Caracterização anatômica e citométrica em biribazeiro (Rollinia mucosa [Jacq.])

The biribazeiro (Rollinia mucosa [Jacq.]) is a native fruit of Central America and South America that stands out from the other species of the genus because it has large and edible fruits. Considering that little is known about the anatomy of the plant, the type of reserve of the seed, as well as little is known about the DNA content of species of Annonaceae family, this study aimed to characterize seeds histochemically and seedlings anatomically, and determine DNA content of biribazeiro (Rollinia mucosa [Jacq.]). The seedlings were obtained from seeds collected in the Amazon region by Embrapa Roraima and then, sent to UFLA, Federal University of Lavras, Minas Gerais State. The pulp of the fruits were extracted and the seeds were previously washed and sown in trays of 48 cells containing sawdust as substrate, remaining in a germination chamber at 30oC for 90 days. A histochemical analysis, anatomical characterization and determination of DNA content of the plants obtained were made. The main conclusions of this research were: (1) the seeds of Biribazeiro (Rollinia mucosa) present mainly lipid reserve, (2) The cross-sections of the leaf blade indicate dorsiventral organization, hypostomatic with paracitic stomata and trichomes on both sides of the sheet (3) the leaves of biribazeiro have on average 4.77 pg of DNA.

Tissue Culture Applications for the Genetic Improvement of Plants

The culturing of cells, protoplasts, and tissues is one of the most successful areas in the realm of biotechnology. The manipulation of cells and cellular components, tissue handling, large-scale and high-speed seedling production, and the adoption of techniques for the genetic improvement of plants are just some of the many important areas of tissue culture. Advances in understanding the physiology of growth and in vitro development have led to the optimization of methods for accelerating and improving plant development. Furthermore, tissue culture methods can produce numerous benefits in conventional breeding programs by offering a method to overcome the limitations of the reproductive system.

Cytological characterization of Jatropha curcas callus in different periods of cultivation

The aimed was characterization and determining the time for Jatropha curcas callus subculture. The pattern of J. curcas callus development is sigmoidal with 5 distinct phases, and transplantation should be performed at the end of the deceleration phase (approximately day 28). During callus development, it was observed that at the onset of growth in the exponential phase the cells were internally disorganized; in the linear phase, respiratory metabolism was resumed through reorganization of the first mitochondria; and by the mid-deceleration phase, the cells were entirely active, and several organelles were detected. This organizational status was maintained throughout the stationary phase during which somatic pre-embryos were identified. At the end of the stationary phase, intracellular disruption began, and the cells entered senescence, which characterized the decline phase for the J. curcas calli growth curve.