Marília Pereira Machado

Influence of calcium content of tissue on hyperhydricity and shoot-tip necrosis of in vitro regenerated shoots of Lavandula angustifolia Mill.

In the present study, the effects of two CaCl2.2H2O levels (440 and 1320 mg L-1) and two subcultures were evaluated on in vitro shoots of Lavandula angustifolia cv. Provence Blue. Ca2+ content of the apical, middle and basal portion of shoots was determined. Increasing CaCl2.2H2O level in the culture medium increased tissue Ca2+ content and decreased hyperhydricity. Shoot-tip necrosis also decreased with 1320 mg L-1 CaCl2.2H2O, but it did not occur in the second subculture. The middle and basal portion had higher Ca2+ content than apical portion. In non-hyperhydric tissues, there were smaller and more juxtaposed cells. Scanning electron microscopy of the leaves demonstrated that trichomes from in vitro leaf surface occurred in smaller quantities.

Propagação in vitro e caracterização química do óleo essencial de Lavandula angustifolia cultivada no Sul do Brasil

Lavandula angustifolia Mill. e uma importante planta produtora de oleos essenciais, que apresenta dificuldade de propagacao pelo enraizamento de estacas, sendo a producao de mudas realizada nesse trabalho pela tecnica de micropropagacao, em que foram avaliadas algumas condicoes do cultivo in vitro. As mudas produzidas pela micropropagacao foram cultivadas em Sao Joaquim (SC). O oleo essencial das inflorescencias foi extraido por hidrodestilacao, e analisado quanto a sua composicao por GC/MS, em dois anos de colheita. O meio de cultura LS apresentou melhor resposta no desenvolvimento das brotacoes, nao sendo observadas brotacoes com necrose apical. Meios de cultura mais diluidos como o ½ MS e o WPM, apresentaram altas taxas de hiperidricidade e necrose apical das brotacoes. A citocinina BAP influenciou a multiplicacao das brotacoes, sendo a qualidade mantida com 1,0µM ao longo de quatro subcultivos. A sobrevivencia das plantas na aclimatizacao foi de 80%. Os teores de oleo essencial foram de 4,0% e 5,25%, na primeira e segunda colheita, respectivamente. Os compostos majoritarios foram o linalol (46,88% e 37,25%) e acetato de linalila (10,09% e 12,24%).

Produção de biomassa, teor e composição do óleo essencial de Mentha x piperita L. em resposta a fontes e doses de nitrogênio

Nitrogen fertilization affects the essential oil yield and composition of aromatic plants. The objective of this work was to evaluate the effect of nitrogen sources and doses on biomass production and essential oil yield and composition of M. x piperita L. The experimental design was in randomized blocks with four replications and the treatments in a 2 x 3 factorial design, corresponding to two nitrogen sources and three nitrogen doses. The nitrogen topdressing was applied 30 days after planting. The essential oil was obtained by hydrodestilation using a Clevenger apparatus, and the composition was analyzed by gas chromatography and coupled to a mass spectrometry. The nitrogen sources and doses did not significantly affect the leaf and stem biomass, as well as the essential oil yield and productivity. However, the nitrogen source can significantly change the essential oil composition of M. x piperita. The level of menthol and neomenthol was lower when 40 kg ha-1 of urea was applied compared to the same dose of ammonium sulphate. Menthone levels were affected only by the nitrogen source, where higher levels were observed when ammonium sulphate was applied. No changes on menthofurane levels were found for different nitrogen sources and doses. Considering the great economic importance of menthol from mint essential oils, the obtained results indicated that the use of 20 kg ha-1 of nitrogen is enough to guarantee satisfactory essential oil yield and great menthol levels and that high doses of urea should be avoided.

Desenvolvimento da camomila, rendimento e qualidade do óleo essencial em diferentes idades de colheita

Chamomile is an aromatic herb with many medicinal properties. In Brazil, it is cultivated on an extensive area in the Southern region mainly because of its climatic conditions for this culture. Chamomile harvesting is done by several cuttings of the entire plant, but the ideal starting point of this activity to obtain high production of flower heads has not been determined. This work investigated the effect of the harvesting period of chamomile on flower head development and essential oil accumulation. The experiment was carried out at field conditions in Piraquara, Parana, Brazil. The experimental design was completely randomized with five treatments (85, 92, 99, 106 and 113 days after emergency) and five replications. After each harvest, dry mass accumulation and essential oil yield and quality were evaluated. Essential oil extraction was performed by hydrodistillation, and the sample was analyzed by gas chromatography. When harvested 85 days after emergency, the flower heads presented the highest essential oil content, but three weeks later the highest flower head dry mass was obtained, which resulted on great essential oil productivity. From 113 days after emergency, there is a reduction in essential oil yield and production.

Avaliação de germoplasma de camomila e densidade de semeadura na produção e composição do óleo essencial

The cultivar Mandirituba is the only genetic material for chamomile cultivation in southern Brazil. Besides the limitations regarding floral buds and the yield of essential oil presented by this cultivar, phytosanitary problems have also been observed. The objectives of this work were to compare the genetic materials from the Netherlands, Denmark and Mandirituba and to evaluate the effect of seeding rate on floral heads development and essential oil production, yield and quality. The experiments were carried out at field conditions in Piraquara, Parana state, Brazil. The essential oil extraction was obtained by hydrodistillation using a Clevenger apparatus and the oil composition was analyzed by gas chromatography coupled to mass spectrometry (GC/MS). The genetic materials from the Netherlands and Mandirituba presented statistically higher dry mass accumulation than the ones from Denmark. However the material from Mandirituba showed a great essential oil yield (4.7 mL g-1 ms) and productivity (2.40 L ha-1). The genetic material from Denmark and Mandirituba showed similar essential oil composition. The density of 1.0 kg ha-1 for cultivar Mandirituba resulted on great plant development and essential oil production. The use of 3.0 kg ha-1 of seeds did not increase plant density due to the high plant competition.

Yield and chemical composition of the essential oil of species of the Asteraceae family from Atlantic Forest, South of Brazil

Abstract The essential oil yield and composition of 17 species of the Asteraceae family were evaluated. Samples were obtained by hydrodistillation of the leaves and inflorescences and they were analyzed by GC-MS and GC-FID. A total of 13 species presented essential oils with yields ranging from 0.06 to 3.36% in fresh samples and from 0.07 to 2.53% in dried samples. Erechtites valerianifolius (Wolf) DC. produced the highest essential oil yield from both fresh and dried samples. Seventy-nine constituents were identified in essential oils from Asteraceae species, mainly consisting of monoterpenes and sesquiterpenes.

Changes on microsatellites of expressed sequence tag of sugarcane (Saccharum spp) during vegetative propagation

The reduction in sugarcane productivity in subsequent cutting stages may be related to a gradual decrease of the allele number and mean observed heterozygosity (HO) in the sugarcane ratoon. This hypothesis was tested assessing the number of alleles and HO values in 10 expressed sequence tag microsatellites (Est-SSR loci) of the sugarcane varieties RB72454 and RB867515 in different cutting stages. Changes of allele numbers in samples of different cutting stages were observed in seven and six EstSSR loci of the RB72454 and RB867515 varieties, respectively. Reduction of allele numbers was observed in the samples collected in the fourth and sixth cutting stages of the RB72454 variety. In contrast, an increase of the allele numbers was detected in the samples collected on fourth, sixth, and seventh cutting stages of the RB867515 variety. Unchanged allele numbers were observed only in EstB41, EstC84, and EstB130 loci of the RB72454 variety, and EstB41, EstC67, EstA68, and EstB130 loci of the RB867515 variety. The variety RB867515 has lower polymorphism and values of HO than the RB72454 variety in different stages of cutting. At molecular level, in Est-SSR loci, the RB72454 variety showed higher changes in subsequent stages of cutting than RB867515. The similarities and divergences at molecular level between varieties RB72454 and RB867515 observed in the 10 Est-SSR loci during subsequent cutting stages can not explain the reduced productivity frequently observed after subsequent cutting stages but showed that phenotypic and physiological changes after each cutting stage are also accompanied by changes at genomic level.

APLICAÇÃO DE ÁCIDO GIBERÉLICO EM MUDAS MICROPROPAGADAS DO PORTA-ENXERTO DE MACIEIRA MARUBAKAIDO

After the acclimatization micropropagated plantlets can showed stop of vegetative growth characterized as a dormency type. For the overcoming of the dormency and return to the growth of the plants applications of Gas are frequent efficient. The objective of this work was to evaluate the effect of different concentrations of giberellic acid (GA 3 ) on the growth of microprop agated ‘Marubakaido’ rootstocks apple plantlet. The plantlets in greenhouse with approximately three cm of height, had received biweekly applications from GA3 in the concentrations of 0, 400 and 800 mg.L-1 in a total of three applications. After 15 days of the last application of the GA 3 one evaluated it height from the plants, leaf number, percentage of plants with bud tip opened and percentage of plants with bunch lateral. The largest concentration of GA 3 (800 mg.L-1) was the best for the majority the variables analyzed, and the concentration of 400 mg.L1 differing significantly from non-treated plants to variables number of leaves and percentage of bud tip opened. The GA 3 improve the