Ana Cristina Portugal Pinto de Carvalho

Avaliação de substratos e adubos orgânicos na aclimatização de plântulas de Heliconia psittacorum

The objective of this work was to evaluate the efficiency of three organic substrates, carbonised rice hull, dry and green coir dust, and two fertilizers, Vitasolo® and earthworm humus, in the acclimatization of plantlets of Heliconia psittacorum L., obtained from micropropagation. After 75 days, the height of the plants, diameter of pseudo-stem, number of leaves and area of the third leaf were evaluated. The rice hull was more efficient than the coir dust (dry or green); the green coir dust was more efficient than dry coir dust; and the humus was more efficient than Vitasolo®.

Artificial light and growth regulators on the in vitro etiolation of Cattleya labiata

The technique of etiolation is widely used in the micropropagation of various plant species. The aim of this study was to evaluate growth and development in shoots of Cattleya labiata grown in vitro, as a function of growth regulators and the presence and absence of light. Stem segments, approximately ± 1.0 cm in height, were inoculated in test tubes containing 15.0 mL of MS culture medium supplemented with different concentrations of BAP (0.0, 2.0 and 4.0 mg L-1) and NAA (0.0, 1.0 and 2.0 mg L-1), and in different growth environments (growth room, darkness and a photoperiod of 16 hours) in a completely randomised design. At 150 days, the following were evaluated: a) number of etiolated shoots; b) number of nodes per etiolated shoot; c) length of stem segment (cm); d) number of roots; and e) total seedling dry weight (g). The highest mean values were achieved with the use of 4.0 mg L-1 BAP and 1.0 mg L-1 NAA for the number of etiolated shoots, and 2.0 mg L-1 NAA for the number of nodes per etiolated shoot in the absence of light. The length of the main shoot was greater in the absence of light; in contrast, the number of roots and the total dry weight of etiolated nodal segments were greater in a bright environment, irrespective of the growth regulator added to the culture medium. The etiolation of stem segments is a viable technique, as it provides features that are advantageous in the in vitro multiplication stage of the species.

Número de explantes, meio de cultura e fotoperíodo na micropropagação de abacaxizeiro ornamental

One of the factors limiting the expansion of commercial cultivation of the ornamental pineapple, Ananas comosus var. erectifolius (LB Smith) Coppens & Leal, is the availability of plantlets in quantity and of quality. Micropropagation makes it possible to obtain higher rates of multiplication, and ensures the high quality of the resultant plantlets; however the cost of producing this kind of propagating material is still relatively high. This study therefore aimed to determine a more appropriate relationship between the number of explants per flask, culture medium and photoperiod, with a view to increasing the in-vitro rate of multiplication of this variety of ornamental pineapple, and consequently optimise production costs of the micropropagated plantlets. A completely randomised design was used, with treatments involving three factors: number of explants per flask (4, 5 and 6), culture medium (MS + 0.54 µM NAA plus 2.22 µM or 4.44 µM BAP) and photoperiod (12 and 16 hours), with ten replications. At the rates of multiplication obtained, there were significant differences for photoperiod and interaction of the three factors under analysis. No significant differences were noted for the number of explants per flask, or for the culture medium taken alone. From an economic standpoint, the use of six explants per bottle is recommended, grown on a medium of MS + 4.44 µM BAP + 0.54 µM NAA, under a photoperiod of 12 hours.

Aclimatização de mudas micropropagadas de Bastão do Imperador em diferentes volumes de recipientes

The Brazilian market of tropical flowers is in a rapid growth stage. The climate of the Brazilian northeastern region, however, tends to hamper plant acclimatization. Considering this, our study aims at determining the most appropriate container (concerning to capacity) to acclimatize micropropagated Torch Lily (cultivar Porcelana) in a greenhouse. The experimental design was randomized blocks with four treatments (container capacities) and five replications. The tested container capacities were: V1 = 50cm3 (small glass - CP); V2 = 150cm3 (small plastic tube - TP); V3 = 300 cm3 (large plastic tube - TG); V4 = 450cm3 (small vase - VP). The characteristics evaluated were: the number of leaves (NF), seedling height (AM), stem diameter (DP), fresh shoot weight (MFPA), fresh root weight (MFSR), dry shoot weight (MSPA) and dry root weight (MSSR). Data were examined by analysis of variance and the Tukey test. The results point to the 450cm3 container as the best suited for Torch Lily acclimatization, since it provided the best seedling growth.

ACÚMULO DE BIOMASSA E NUTRIÇÃO DE MUDAS MICROPROPAGADAS DE BANANEIRA PRATA CATARINA ADUBADAS COM BIOFERTILIZANTES

Banana farming is an activity of great economic and social importance, and is carried out in most tropical countries. The aim of this work was to evaluate the biomass accumulation and levels of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in micropropagated plants of the banana „Prata Catarina‟ during the acclimatization phase, under different types and doses of biofertilisers. The experimental design included randomised blocks in a 2 × 5 + (2) factorial scheme, with two types of liquid biofertilisers (bovine biofertiliser with anaerobic and aerobic fermentation) and five biofertiliser doses (0.25, 0.50, 0.75, 1.00, and 1.25 L plant week), as well as two additional treatments (control and recommended mineral fertilisation). The following variables were analysed: dry weight of the leaves and roots, and mineral element content (N, P, K, Ca, and Mg) in different parts of the plant (leaf and root). During 90 days of acclimatization, the nutritional contribution of bovine biofertiliser with anaerobic fermentation was greater in comparison with the biofertiliser with aerobic fermentation and the control, but lower in comparison with mineral fertilisation. The 1000-mL dose of the biofertiliser with anaerobic fermentation promoted greater dry weight accumulation in the leaves and roots of the banana „Prata Catarina‟. The biofertiliser with anaerobic fermentation promoted higher levels of N, K, and Ca in the leaves, whereas the biofertiliser with aerobic fermentation promoted higher levels of P in the leaves and roots.