Ronan Carlos Colombo

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.

SILÍCIO NO DESENVOLVIMENTO IN VITRO DA ORQUÍDEA Cattleya forbesii

Addition of Silicon (Si) to culture media has been shown to improve the development of seedlings grown in vitro, and to reduce losses during the acclimatization phase. The objective of this study was to evaluate the in vitro growth of Cattleya forbesii (Orchidaceae) in MS medium containing five different concentrations of SiO2 (0.0, 0.5, 1.0, 1.5, and 2.0 g·L ). At day 200, the following variables were measured: number of roots, average length of the root system, leaf area, number of leaves and shoots, shoot height, fresh and dry masses of roots and shoots, water content of roots and shoots, and pH of the culture medium. Most variables decreased as the concentration of Si increased, reducing the in vitro vegetative growth of C. forbesii. Accumulation of Si in leaf tissues was detected by scanning electron microscopy, confirming uptake by plants. The Si source and concentrations tested showed no beneficial effect on in vitro growth of C. forbesii.

Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes

The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

Cultivo in vitro de Vanda tricolor Lindl. em meios de cultura simplificados

As orquideas do genero Vanda sao apreciadas pela exuberância de suas floradas e, diferentemente de outras orquideas, essas plantas, de crescimento lento e monopodial, nao apresentam brotacoes laterais que dao origem a novas mudas, caracteristicas estas que lhes conferem alto valor de mercado. Entao, para produzi-las em escala comercial, e preciso recorrer as tecnicas de propagacao in vitro, em que o meio de cultura adequado e um dos fatores mais importantes para o desenvolvimento das plântulas. Plântulas de Vanda tricolor, aos 150 dias de idade, foram subcultivadas em meio MS e meios de cultura a base de fertilizantes comerciais, com e sem adicao de polpa de banana ‘Nanica’ (100 g L–1). O delineamento experimental adotado foi o inteiramente casualizado, composto por 12 tratamentos e seis repeticoes, com sete plântulas. Aos 180 dias, avaliaram-se as variaveis: area foliar; numero de folhas e raizes; comprimento medio do sistema radicular e a materia seca das folhas, raizes e total. Conclui-se que e possivel utilizar o meio simplificado a base de fertilizante Biofert® (08-09-09) acrescido de polpa de banana em substituicao ao meio MS para o desenvolvimento in vitro de V. tricolor

Collect Seasons, Indolebutyric Acid and Substrates on Rooting of ‘Bengal’ Lychee Cuttings

Lychee ( Litchi chinensis Sonn.) propagation by cuttings is a promising alternative in commercial production of seedlings, since it is an easy procedure, in addition to enabling the standardization in the field and the reduction in production costs. Therefore the objective of this work was to evaluate ‘Bengal’ lychee cuttings rooting, collected in spring and summer, using different concentrations of indolebutyric acid (IBA) and substrates. The experimental design was completely randomized, in a 3 × 3 factorial arrangement, with 5 replications and 10 cuttings per plot, and the following factors were adopted: IBA concentrations (0; 1,000 and 2,000 mg L -1 ) and types of substrates (carbonized rice husk, vermiculite medium granules and coconut fiber). At 140 days, the following variables were evaluated: cuttings survival; leaf maintenance; cuttings unrooted with calli; cuttings rooted; roots number per cutting; root length and root dry mass. In addition, the pH, electrical conductivity, density and water retention capacity of the substrates were evaluated. There was no difference in IBA concentrations applied in both evaluated periods. However, in the spring, the carbonized rice husk provided highest mean for the measured variables. On the other hand, in the summer, the rooting percentage presented a lower average in all substrates (< 1%), independent of the IBA concentrations. It was concluded that the ‘Bengal’ lychee propagation by cutting can be carried out in the spring, using carbonized rice husk as substrate, without IBA.

Substrates and irrigation levels for growing desert rose in pots

In the past decades, desert rose has become a very popular ornamental plant, especially among collectors, due to its exotic and sculptural forms. However, it has been grown on a commercial scale only recently, and little is known about how to best manage it as a container-grown plant, or even which potting medium (substrate) to recommend. Therefore, the aim of this study was to investigate the interactions between potting media and irrigation levels for growing desert rose as a potted ornamental plant. The experiment was conducted in a greenhouse using a 6 x 2 factorial arrangement with six replications, six potting media and two irrigation levels. The mixes were characterized by measuring their physical properties, specifically the density and water retention capacity (WRC), as well as chemical properties, such as the pH and electrical conductivity (EC). After 210 days, plant growth and plant water consumption were evaluated and measured. A lower dry density for the vermiculite mixes was observed in comparison to that for the sand mixes. However, WRC ranged from 428 to 528 mL L-1 among the mixes, values considered close to ideal. In general, plant growth exhibited higher increases in mixes consisting of coconut fiber + sand or vermiculite, regardless of the irrigation level. Mixes of vermiculite + coconut fiber and sand + coconut fiber can be used to grow desert rose in pots, as long as irrigation is used to maintain the moisture content of the potting medium (mix) between 60-70% and 80-90% of the WRC.

Methods of aril removal and lightness conditions on seeds physiological quality of sour passion fruits

Passion fruits species presents a larger economic importance for in natura consumption and industry. The main way to propagate these species is by seeds; however, the aril presence and environmental conditions may inhibit the seeds germination. In this sense, the objective of this study was to evaluate the effect of aril removal methods and light conditions on P. edulis var. flavicarpa seeds quality and germination. There were used five methods to remove the seeds aril: (1) friction on steel mesh sieve for 5 minutes; (2) friction with coarse sand on steel mesh sieve for 5 minutes; (3) immersion in lime solution at 10% (w/v), for 30 minutes; (4) fermentation in sugar solution at 10% (w/v), during 48 hours; and (5) natural pulp fermentation, during five days. The seeds were submitted to germination test at darkness and lightness, as well as, to length seedlings and emergence test. Regardless the aril removal method, the germination percentage was lower at lightness than darkness highlighting the natural pulp fermentation treatment, which presented 86% of seeds germinated. On the other hand, the aril removal methods did not affect the seedlings emergence, with emergence percentages ranged from 88 to 94%.

PHYSICAL-CHEMICAL QUALITY OF MANGO ‘Ubá’ (Mangifera indica L.) FRUITS SUBMITTED TO IMPACT MECHANICAL DAMAGE AT HARVEST

O objetivo deste trabalho foi avaliar a qualidade da manga ‘Uba’ submetida a injuria mecânica de impacto. Os frutos foram colhidos, na safra 2012/2013, e deixados cair uma unica vez sobre uma superficie plana e rigida, simulando o processo de colheita da manga ‘Uba’, que consiste em derrubar todos os frutos de uma planta, quando os mesmos encontram se fisiologicamente maduros. As alturas de queda: zero, um, dois, tres, quatro e cinco metros, formaram seis tratamentos. Apos a queda, os frutos foram submetidos ao amadurecimento, e em seguida avaliados em relacao a perda de massa fresca (PMF), presenca de lesoes externas (PLE), presenca de lesoes internas (PLI), teor de solidos soluveis (SS), acidez titulavel (AT), pH, relacao SS/AT e vitamina C. Nao houve diferenca entre a perda de massa fresca dos frutos que sofreram queda e o controle. Com relacao a PLE e PLI, a tendencia e de aumento da injuria nos frutos relacionada a altura de queda. Os frutos que nao sofreram queda apresentaram maior teor de SS que os demais, enquanto que os que cairam de uma altura de 5 m tiveram o teor de vitamina C reduzido em 27,78% em relacao ao controle. A diminuicao do teor de SS e vitamina C foi influenciada pelos danos provocados pelo impacto. Conclui-se que injurias mecânicas de impacto interferem nos principais atributos de qualidade dos frutos e da polpa de manga ‘Uba’.Blackberry is a shrubby perennial tree with high economic importance among horticultural crops in several countries. The fruit has a good market value, both at national and international level. The objective of this work was to evaluate the multiplication of blackberry cv. Xavante cuttings under different seasons over the year, aiming to improve the production of nursery plants. The experiment was carried out from April 2012 to March 2013 and it was laid out in randomized complete block design with different types of cutting: tip, softwood, semihardwood and root, examined in different seasons: autumn, spring and summer, with 5 replications and 10 cuttings per plot. The variables studied were: cutting rooting, cutting survival, number of roots, length of major roots and roots dry weight. Cuttings of blackberry had a significant temporal variation in the percentage of successful rooting and survival of cuttings. It was verified that softwood and semihardwood cuttings collected in summer are the best option for blackberry cv. Xavante multiplication for commercial production of nursery plants.