Gabrielen de Maria Gomes Dias

In vitro multiplication of ornamental pineapple by shoot etiolation and regeneration

The in vitro multiplication of etiolated nodal segments was evaluated for Ananas comosus var. erectifolius shoots production. Stems were inoculated in the following media: MS without growth regulator; MS + 10 µM of indolbutiric acid (IBA); MS + 10 µM of naphtalenacetic acid (NAA); MS + 10 µM of indolacetic acid (IAA); and stored in darkness at 25±2oC. 60 days after inoculation, the number of etiolated shoots/stem; number of nodes/etiolated shoot; etiolated shoot length, internode length and total number of nodes/stem were evaluated. The medium MS + 10 µM of NAA showed the highest values of number of etiolated shoots and total number of nodes/etiolated shoot. For shoot regeneration, nodal segments from in vitro etiolated stems with two nodes were inoculated in the following media: MS without growth regulator; MS + 4.44 µM of 6-benzylaminopurine (BA); MS + 8.88 µM of BA; MS + 13.32 µM of BA. The flasks were incubated under photoperiod of 16 hours, at 25±2oC. At 30 days of culture, the number of regenerated shoots/explant did not differ in the tested media. At 45 and 60 days of culture, the media with BAP induced higher number of regenerated shoots per node, differing statistically from the control.

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.

Regional Substrates of the Brazilian Northeast on Acclimatization and Development Morphological of Minirose

The transition from heterotrophism to autotrophism in acclimatization is a delicate process for most species. The objective of this work was to evaluate combinations of regional substrates of the Brazilian Northeast in the acclimatization and morphological development of minirose ( Rosa chinensis ‘Minima’) seedlings. The experiment was carried out in a greenhouse using seedlings with 30 days of in vitro culture. The treatments were constituted by: 1) dry coconut powder; 2) 75% dry coconut powder + 25% rice husk; 3) 50% dry coconut powder + 50% rice husk; 4) 75% dry coconut powder + 25% charcoal rice husk; 5) 50% dry coconut powder + 50% carbonized rice husk; 6) 100% vermiculite; 7) 50% vermiculite + 50% dry coconut powder; 8) commercial substrate; 9) 75% sand + 25% dry coconut powder and 10) 50% sand + 50% dry coconut powder. After 21 days, the following characteristics were evaluated: survival percentage, leaf number, shoot height, dry matter of shoot and root and total dry matter. The regional materials tested showed a good choice of substrates to be used in the acclimatization of minirose seedlings. The vermiculite presented the worst results in the characteristics evaluated. Dry coconut powder as substrate should be used in mixtures with other materials to provide better acclimatization conditions. The use of 50% dry coconut powder + 50% rice husk provided a best development and growth of minirose seedlings ( Rosa chinensis ‘Minima’) than other tested substrates

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.

Morpho-physiological changes in Billbergia zebrina due to the use of silicates in vitro

The use of silicon in Billbergia zebrina cultivation in vitro is an alternative for optimizing micropropagation of this important ornamental plant species. The objective of the present study was to evaluate the growth and anatomical and physiological alterations in Billbergia zebrina (Herbert) Lindley plants as a function of different sources and concentrations of silicon during in vitro cultivation and acclimatization. The experimental design was completely randomized, with a double factorial arrangement and an additional control treatment (2 x 3 + 1). The first factor was relative to calcium silicate and sodium silicate added to the Murashige & Skoog culture medium; the second factor was related to its concentrations, 0.5, 1.0, and 2.0 mg L-1. After 100 days, their growth, anatomical characteristics, level of silicon and chlorophyll content were evaluated. Growth characteristics were assessed after 60 days of acclimatization period. Plants absorbed more sodium silicate than calcium silicate. This source also stressed the plants impairing their growth, but the highest silicon absorption at 1 mg L-1 attenuated the stressful conditions. The supplementation of the culture medium with calcium silicate led to improved growth, anatomical, and physiological characteristics, which benefited the development of more resistant seedlings with better performance during acclimatization.

Potássio e sódio na composição mineral e crescimento em plantas de Zingiber spectabile

For tropical ornamental plants there is no information in the literature regarding the interaction of sodium (Na) with other nutrients, especially potassium (K). Given the above, the objective of this study was to evaluate the symptoms of nutritional deficiencies, growth and mineral composition of plants Zingiber spectabile subjected to K relations: In in nutrient solution. Treatments with different relationships K: Na (mmol L-1) were: 6K:0Na, 5K:1Na, 4K:2Na, 3K:3Na, 2K:4Na, 1K:5Na and 0K:6Na. We used the experimental randomized block design with four replications, and the experimental plot was composed of one plant per pot. After 180 days, the plants were harvested, and the biometric indexes and dry weight of different parts of the plants evaluated, and thereafter performed chemical analysis of the plant tissues. Sodium proved beneficial element for the initial growth of Zingiber spectabile. Sodium from 2 mmol L-1 can partly replace potassium in the initial culture of Zingiber spectabile in nutrient solution.

Induction of embryogenic calluses in in vitro pink torch ginger.

With the purpose of obtaining embryogenic calluses, different auxins and inoculation position of the explants were evaluated. Rhizomes of about 0.5cm obtained from micropropagated seedlings were cut lengthwise at half and inoculated in test tubes. After inoculation, the cultures were kept in growth room at 25±2oC in the dark. The completely randomized design in a factorial scheme 6x2, represented by five auxins (ANA; AIB; AIA; 2,4-D and picloram) at the concentration of 10µM and a control (without auxin) and two explant positions (H-horizontal and V-vertical). The experiment was constituted of five replicates with three tubes each containing one explant. After 50 days’ cultivation, both the percentage of oxidation and callus formation were evaluated. The data were transformed to √x+0.5 and studied by utilizing the SISVAR program and the means compared by the Skott-Knott test at 5% of probability. In the culture medium added of 1,4-D, all the explants formed calluses. The explants inoculated in the culture medium containing picloram did not differ statistically with relation to the inoculation position of the explants, which presented 87% (V) and 80% (H) of calluses. For the percentage of oxidation, thee were no statistic difference among the treatments, but on those added of 2,4-D, ANA and AIA at the upright position, no oxidation as found. So, the MS medium added of 10µM of 2,4-D and the rhizome inoculated at the upright position were the ones which presented highest percentage (100%) of embryogenic callus induction. Keywords: Etligera elatior, In vitro propagation, Zingiberaceae