Roberto Jun Takane

Cryopreservation of seeds of Encholirium spectabile Martius ex Schultes f. by the vitrification method

The bromeliad Encholirium spectabile Martius ex Schultes f. is a endemic species of the Caatinga. The aim of this study was to evaluate the efficiencies of cryoprotectant in bromeliad seeds. The treatments consisted of immersing seeds in different cryoprotectant solutions and vitrification solutions before immersion in liquid nitrogen (NL) at -196 °C, as the following treatments: T1- Control: without cryoprotectants; T2- glycerol 2M (20 min) + PVS2 (10 min), T3- glycerol 2M (20 min) + PVS2 with phloroglucinol 1% (10 min), T4- sucrose 0.4M (20 min) + PVS2 (10 min); T5- sucrose 0.4M (20 min) + PVS2 with phloroglucinol 1% (10 min); T6- glycerol 2M (20 min) + sucrose 0.4M (20 min) + PVS2 (10 min), T7- glycerol 2M (20 min) + sucrose 0.4M (20 min) + PVS2 with phloroglucinol 1% (10 min). The experimental design was a completely randomized design with seven treatments and five replicates per treatment. Data were subjected to analysis of variance (ANOVA) and means were compared by the Tukey test at 5%. The seed moisture at the beginning of the experiment was 8.4%. There were statistically significant for the variables percentage of seeds germinated and seedling length, but for the variable seedling dry weight, T3 treatment was presented a value statistically high to T1, T4, T5 and T6, but did not differ from T2 and T7 treatments. It is concluded that for the cryopreservation of seeds of Encholirium spectabile is not necessary to use cryoprotectant solutions.

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.

Substrates and containers for the development of Brassica pekinensis L. seedlings

The aim of this study was to evaluate the development of Chinguensai (Brassica pekinensis L.) seedlings, under different formulations of substrates and sizes of containers, in Fortaleza, Ceara. For this, two studies were conducted in factorial design with randomized blocks and four replicates. The first study was conducted in a factorial (4 × 4) design. Four substrate formulations (powder-type coconut fiber; carbonized rice hull and earthworm casting) had the following proportions: S1 (1:1:1); S2 (0:1:1); S3 (1:0:1); and S4 (0:0:1) by volume basis (v/v) and four evaluation dates (22, 27, 34 and 41 days after sowing — DAS). The second study was conducted in a factorial (3 × 4) design with three types of containers with different cell volumes (31, 18 and 11 cm3) and four evaluation dates (22, 27, 34 and 41 DAS). The fresh and dry weight of the shoot and root systems was evaluated. Both studies showed no interaction between the variables, with differences noted for substrate factors, containers and times in all traits. In the first study, the earthworm compost resulted in the highest yield of fresh and dry seedling weight. In the second study, the container with 31 cm3 of cell volume showed the highest production of fresh and dry weights. The results showed that the substrate composed solely of earthworm humus and with the use of trays with 31 cm3 of cell volume provided seedlings of Chinguensai with the optimal production for transplanting 41 DAS.

Efeito do regulador daminozide e dos substratos fibra de coco e areia no cultivo em vaso de girassol ornamental

This study aimed to evaluate the effect of applications and levels of the plant growth regulator daminozide on the growth of ornamental sunflower (Helianthus annuus cv. Dwarf Sunbright kids) in pots containing coconut fiber or sand as substrate within environmental conditions of Fortaleza. The design used was completely randomized using a 2 x 5 factorial arrangement consisting of two types of substrate (coconut fiber and sand) and five levels of daminozide (0, 2, 4, 6 e 8 g L -1 ) that were applied three times during the experiment: at 15, 30 and 45 days after sowing. At 37 DAS, it was analyzed: the relative chlorophyll index of leaves, which considered the intensity of green color of the leaves; leaf gas exchange, measured through the leaf temperature, transpiration rate, stomatal conductance and net photosynthesis. At the end of the experiment, we analyzed: the plant height ; stem diameter; internal diameter of the head ; days from sowing to anthesis; number of heads; leaf area; the dry matter of leaves, stems, heads and roots, and determined the dry matter of roots and aerial part relation. For Cientifica, Jaboticabal, v.42, n.4, p.376–387, 2014 ISSN: 1984-5529 377 both substrates, the increase in daminozide levels reduced plant height, stem diameter and internal diameter of the head, delaying the anthesis of inflorescences, reducing the leaf area and increasing relative chlorophyll index of leaves, which was evidenced for its greater intensity of green color. Sunflowers that were grown in sand presented lower values of plant height, stem diameter and leaf area. There was a significant different effect of substrates on leaf gas exchange: plants grown in FC presented higher levels of stomatal conductance, transpiration rate and net photosynthesis. Additional keywords: gibberellin inhibitor; Helianthus annuus; potted plants; substrates.

Pimenteira ornamental submetida a tratamentos com daminozide em vasos com fibra de côco ou areia

The demand for ornamental pepper as “potted plants” is growing. It is possible to produce these plants with growth regulators in substrates easily acquired and capable of providing high quality plants at low cost. The present study had the goal of evaluating the effect of applications of levels of the regulator daminozide on ornamental pepper grown in pots containing coconut fiber (FC) or sand as substrates. A completely randomized design was employed in a 2x5 factorial scheme consisting of two types of substrate (FC and sand) and five levels of daminozide (0, 2, 4, 6 and 8 g L -1 ) applied three times during the experiment, at 25, 40, and 55 days after sowing. The following variables were analyzed: plant height, stem diameter, number, width and length of fruits, dry matter of leaf, stem, fruits, and root, 1