Gerson Renan de Luces Fortes

Protocolo para produção de material propagativo de batata em meio líquido

Abstract – Semi-solid media are more commonly used in studies of micropropagation, but the physicalstate of the culture media seems to influence the growth and multiplication rate of the cultivation. Theobjective of this work was to establish a protocol for in vitro multiplication of potato in liquid culturemedia. Potato explants, cultivar Eliza, with an axillary bud, were cultivated in six different culturemedia, with (semi-solid) or without (liquid) the addition of agar. After 21 days, the culture medium thatprovided the best results for growth and multiplication rate had the composition modified with theobjective of improving the efficiency of in vitro multiplication of five cultivars in liquid medium. Theneed of agitation was also evaluated in liquid culture medium. There was high efficiency of the in vitropotato multiplication when it was cultivated in liquid medium. The MS salt medium in the full concen-tration, added by gibberellic acid (0.25 mg L -1 ), panthotenic acid (5.0 mg L ), thiamine (1.0 mg L

Identificação e controle com antibióticos de bactérias endofíticas contaminantes em explantes de batata micropropagados

This work aimed to isolate, characterize and identify contaminant endophytic bacteria found in potato tissues during the micropropagation and to select antibiotics for in vitro control of these microorganisms by determining the inhibitory minimal bactericidal concentration. Potato shoots pre- senting bacterial contamination during the in vitro multiplication were superficially sterilized and the internodes transferred to Petri dishes with nutrient agar medium for up to five days at 28°C. After subcultures the grown bacteria were purified and identified through taxonomic tests. A total of eight bacterial endophytic strains were isolated and identified as belonging to Acetobacteriaceae (1) and Enterobacteriaceae (2) families and Corynebacterium (3), Pseudomonas (1) and Xanthomonas (1) genera. The best results for bacterial growth inhibition were obtained with ampicilin, chlorampheni- col, streptomycin and tetracycline antibiotics in concentrations ranging from 32 to 256 mg L -1 .

ENRAIZAMENTO DE MINIESTACAS DE AMEIXEIRA

The trial aimed to maximized the yield of the number of plum cuttings per branch. Growing shoots of two plum cultivars (Reubennel and Pluma 7) were used. The apical portion with diameter shorter than 2 mm was eliminated. The mini-cuttings were obtained by making a 0.5 cm cut above the bud and another one next to the subsequent bud. The mini-cuttings were immersed in a solution of IBA 2000 mg.L-1 for five seconds. As control, a solution composed of distilled water mixed with the same volume of methyl alcohol was used to dissolve the IBA solution. The mini-cuttings were placed to root in an expanded polyesterene tray containing a mixture of rice husk ash and vermiculite (2:1 v/v) as substrate. Half of this material was covered with (20 micra) thick transparent plastic and the other part without it. The experiment was carried out in a complete randomized block by using a factorial 2x2x2 (cultivar, IBA and plastic film) with four replications and fifteen mini-cuttings per plot. After 39 days the percentage of rooting, root number and length were evaluated. Pluma 7 cultivar showed the highest rooting potential and the highest sensibility to IBA. One - bud cuttings are able to form root. It is possible to obtain rooted cuttings with the whole shoot when they are treated with IBA. It was observed that plastic film reduced the root cutting . IBA increases the rooting, the number and root length of the studied cultivars.

Efeito de auxinas sintéticas no enraizamento in vitro da macieira

Apple shoots (Malus domestica, Borkh), cv. Fred Hough derived from in vitro multiplication process were inoculated in MS and MS/2 basal media added by growth substances indol acetic acid (IAA); indol butiric acid (IBA) and naphtalene acetic acid (NAA) at 0, 1, 3 and 5 µM. The media also included: MS vitamins, myo-inositol (100.0 mg/L); sucrose (30.0 g/L); agar (6.0 g/L). The pH was adjusted to 5.8 before autoclaving. The treatments were incubated in a growth room at 25±2oC, 16 hours photoperiod under light intensity of 2,000 lux during 30 days. The treatments were replicated five times. Each replicate was composed by a 250 mL flask containing 40 mL medium with five explants. The medium MS/2 in all the tested concentrations was better than MS. The NAA and IBA, both at 3.0 µM on MS/2 showed similar effects as percentage of rooting and number of roots are concerned. However, NAA treated explants presented a higher callus incidence at the base of shoots along with thicker roots. IAA had a better response when used in higher concentrations but it did not achieve the performance of IBA ou NAA.

Efeito da aplicação de baixa temperatura em plantas de macieira sobre o crescimento durante a aclimatização

The present work aimed to evaluate the growth of shoots of a rootstock of the plant growth of the apple (Malus prunifolia Borkh, cv.Marubakaido) tree during the acclimatization process. After two weeks of acclimatization, the plantlets were transferred to a growth room and kept under temperature of 4±1oC, 16-hour photoperiod at 5µEm-2s-1 of radiation for 0, 240, 480, 720, 960, 1,200 and 1,440 hours. So, the plantlets were transferred to the greenhouse where their growth was evaluated every two weeks during 90 days. Internode length, bud number and dry matter weight of aerial part and roots were also evaluated at the end of the experiment. The percentage of plant survival was evaluated after a month in greenhouse. An increase was verified in the plant height and internode length proportional to the time kept under low temperature. Chill did not affect the plant survival, the bud number and the dry weight of aerial part, but it did affect the root dry weight.

AVALIAÇÃO DA COMPATIBILIDADE DA ENXERTIA EM Prunus sp.

The work was accomplished aiming to quantify the peroxidase activity and total phenols, in order to verify the physiological and biochemical processes in grafting of Prunus sp. cultivars. The samples were processed and obtained in bark and wood of the peach rootstocks (GF 677, Okinawa, Capdeboscq and Aldrighi) and plum rootstocks (Mirabolano and Marianna), after they had or not been grafted with the stock Diamante, Eldorado and Santa Rosa. It could be concluded that the peroxidase and the total phenols activity influenced the union between stock and rootstock; after grafting, the incompatibility degree is related with high peroxidase activity and total phenols in the rootstock Marianna and Mirabolano. The Santa Rosa plum graft is as compatible to plum rootstocks as to the peach ones.

Produção de mudas pré-básicas de batata por estaquia a partir de plantas micropropagadas

The use of cuttings from micropropagated potato plants can become an efficient technique to improve the multiplication rate of potato genotypes of high genetic quality and sanitary level. A protocol for the production of pre-basic potato material by microcuttings, obtained from plants with a short period of acclimatization, was established. The influence of cutting position (basal, medium and apical), the collection period (15 and 30 days), the immersion time (zero and one minute) in different IBA concentrations (0; 250; 500; 750 and 1000 mg L-1), and substrate types (sand and vermiculite) were analyzed in two experiments. Basal, medium and apical microcutting position presented rooting rates up to 90% when collected from 15 days acclimatization potato plants followed by treatment through fast immersion in IBA solution at 500 mg L-1 and in sand or vermiculite as substrate.

Estabelecimento e multiplicação in vitro de Prunus sp. em diferentes meios de cultivo

The work was performed aiming to evaluate different media for the establishment and in vitro multiplication of some rootstocks species of Prunus. Microcutings of 1,0cm long were incubated under 20 mE.m-2.s-1 radiation provided by white fluorescent lamps, 16-hour photoperiod and temperature of 25±2oC. The establishment media used were as follow: MS, ¾ MS, SH and Villegas, and the multiplication media used were: SH and ¾ MS. The ¾ MS medium was also tested with different agar concentrations (4.5; 5.5; 6.5 g.L-1). The percentage of establishment, contamination, oxidation and growing of the explants were evaluated. The Villegas medium provided low oxidation during the period of in vitro establishment. The ¾ MS medium provided higher percentage of establishment of explants. In the multiplication phase, the highest growth percentage, multiplication rate and bud number, were found in ¾ MS medium with 5.5 g.L-1 agar.

Efeito da sacarose e do benomyl na multiplicação in vitro da macieira

The purpose of this work was to study the effect of sucrose and benomyl concentrations on in vitro multiplication of apple (Malus prunifolia Willd, Borkh). The culture media composition was MS basal media plus 1 mg L-1 of BAP. Benomyl was harmful to M. prunifolia at all concentrations. The best sucrose concentrations was 30-45 g L-1, evaluated by shoot and bud number. The sucrose concentration of 45 g L-1 gave the biggest shoot length. The best shoot color was obtained at 15-30 g L-1 of sucrose.

Uso de ágar, amido e ácido indolbutírico no enraizamento in vitro do porta-enxerto de macieira MM 111

The agar is one of the most expensive componnts in a tissue culture medium when vitro propagation is concerned. This work was carried out in the tissue culture laboratory at EMBRAPA/CPACT, Pelotas RS. The objective of this work was to test the agar action and its partia1 substitution for cassava starch in the composition of the solidifying agent in the MS basal medium associated winth 0; 2.5; 5.0; 7.5 and 10.0µM indolyl butyric acid (IBA). The solidifying agents were as fallows: agar (6g.L-1) agar (3g.L-1) + cassava starch (50g.L-1). The MS basal medium was reduced to half strength and added to myo-inositol (100mg.L-1); sucrose (30g.L-1) and the pH adjusted to 5.9 before autoclaving. The explants were kept for 30 days in the growth room under 25±2°C, 16-hour photoperiod and about 2000 lux light intensity. The use of agar + starch promoted a higher number of roots, and a maximization was observed in the presence of 5µM IBA. It also antecipated the new roots in about 10 days. The consistency of the agar/starch was quite the same as agar e it appeared less transparent.