RESUMOA variação nos elementos meteorológicos ao longo do ano, configurando as quatro estações, proporciona diferentes condições de crescimento e desenvolvimento das plantas, alterando o metabolismo e a constituição dos tecidos vegetais. Assim, o presente trabalho teve o objetivo de determinar a influência da sazonalidade em parâmetros fenométricos e na produção de óleo essencial em Aloysia triphylla (L'Hérit) Britton, submetida a diferentes níveis de reposição hídrica cultivada em ambiente protegido. As avaliações foram realizadas no dia que marcou a metade de cada estação do ano (verão, outono, inverno e primavera), sendo coletado todo o material vegetativo 20 cm acima do solo. A reposição hídrica foi baseada na evapotranspiração de referência (ETo) para o ambiente externo em função dos dados de entrada da equação de Penman-Monteith a qual apresenta parametrizações para dados obtidos em estações meteorológicas em padrões oficiais, sendo assim aplicados 125, 100, 75 e 50% da ETo em turno de rega de dois dias. A produção de massa fresca, seca e de parte aérea, bem como a área foliar, apresentaram maiores valores na estação primavera, sendo o inverno e o verão responsáveis pelos menores valores. O maior teor de óleo essencial foi observado nas estações de menor produção de biomassa, ou seja, verão e inverno. A reposição hídrica que proporcionou maior produção de material vegetativo foi a de 125% da ETo; no entanto, o maior teor de óleo foi observado nas menores reposições hídricas (75 e 50 % da ETo, respectivamente). A produção de óleo foi maior na primavera, a qual não sofreu influência da reposição hídrica ao longo do ano.

ABSTRACTThe variation in weather elements throughout the year, setting the four seasons, provides different conditions for growth and development of plants, altering the metabolism and the structure of plants` tissues. This study aimed to determine the influence of seasonality on fenometrics parameters and on the oil production in Aloysia triphylla (L'Herit) Britton, subjected to different levels of water availability cultivated in greenhouse conditions. The evaluations were made on the day that marked the middle of each season (summer, autumn, winter and spring), and all plant material were collected 20 cm above ground. The water reposition was based on the evapotranspiration reference (ETo) to the external environment being applied 125, 100, 75 and 50% of ETo in an irrigation interval of two days. The production of fresh, dry and aerial part mass, as well as leaf areamass, showed higher values in the spring season, while winter and summer were responsible for lower values. The highest content of essential oil was observed at seasons with lower biomass production. The water availability that provided higher production of plant material was the one with 125% of ETo, however, the highest oil content was observed at lower water availability (75% and 50% of ETo, respectively). The oil production was higher in the spring and was not affected throughout the year by the water availability.

Os fatores ambientais, tais como: temperatura do ar, umidade relativa do ar e radiação solar, influenciam no comportamento fisiológico dos vegetais refletindo no seu crescimento e desenvolvimento. O objetivo do trabalho foi avaliar o comportamento fisiológico em mudas de pata-de-vaca ao longo do dia e constatar qual o melhor horário para a realização de determinações de trocas gasosas. Para tanto, foram realizadas avaliações de temperatura da folha, radiação fotossinteticamente ativa, resistência estomática e transpiração, utilizando-se um porômetro, das 8:00 às 17:00 horas, em intervalos de uma hora entre as medidas. A espécie apresenta oscilações no seu mecanismo fisiológico em função do horário de avaliação e das condições climáticas, sendo o intervalo mais indicado para a realização de determinações das trocas gasosas das 10:00 às 13:00 horas.

Environmental elements, such as air temperature, relative humidity and solar radiation, affect the physiological behavior of plants, which is reflected in their growth and development. The objective of this study was to evaluate the physiological changes of Brazilian Orchid Tree seedlings over a typical day and find the best time to carry out determinations of gas exchanges. For this end, we evaluated temperature of the leaf, photosynthetically active radiation, stomatal resistance and perspiration, using a porometer, from 8:00 a.m. to 05:00 p.m., in intervals of one hour between measurements. The species presents oscillations in its physiologic mechanism in function of the time of evaluation and climatic conditions, being the most suitable interval to determine gas exchanges from 10:00 a.m. to 01:00 p.m.

The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

The effect of divergent selection for ewe multiple-rearing ability over a 15-year period on mutton quality was examined on the M. longissimus dorsi and M. semimembranosus of entire rams (R) and ewes (E) derived from two Merino lines. The selection of these two lines was based on maternal ranking values for multiple-rearing ability in a positive (P) and negative (N) line. In the negative line the replacements were based on the progeny of ewes that rear less than one lamb per joining or lambing opportunity (i.e. failed to lamb or lost all progeny born at least once). Progeny of ewes that reared more than one lamb per joining (i.e. reared twins at least once) were selected for the positive line. Ratings of sensory quality characteristics on the M. semimembranosus of the different genotype lines were obtained from a trained taste panel and related to data on physical and chemical characteristics. The moisture, total lipids, protein, ash, mineral concentrations and fatty acid composition of the M. semimembranosus were obtained. Physical parameters measured on the M. longissimus dorsi were: ultimate pH (pH48), drip loss, cooking loss and Warner-Bratzler shear force (WBS). The influence of selection line on the sensory characteristics of the mutton was generally negligible, with the exception of the sensory attribute of first bite, where meat derived from the positive line was rated to be less tender than that of the negative line contemporaries. Chemically, the meat derived from the four different groups differed significantly in moisture and lipid content. The Positive Ram (PR) group had the highest moisture (ca. 76%) and the lowest lipid (ca. 7%) concentrations, whereas the Negative Ewe (NE) group had the lowest moisture (ca. 70%) and the highest lipid (ca. 10%) concentration. No significant differences were detected in the proximate chemical composition between the P and N lines. The pH48 and WBS values showed significant differences between the four groups. The Negative Ram (NR) group had the highest pH48 and the lowest WBS values. Results indicated a line effect on WBS tenderness. Meat derived from the positive line was less tender compared to the meat from the negative line. Differences between the reproductive lines pertaining to the mineral and fatty acid composition were also noted. A general tendency found, was for the Positive Ewes (PE) to have the highest and the NE to have the lowest mineral concentration. Significant differences were detected between the four groups in the individual fatty acids arachidic acid (C20:0), lignoceric acid (C24:0), eicosenoic acid (C20:1n-9), linoleic acid (C18:2n-6), homo-y-linolenic acid (C20:3n-6), arachidonic acid (C20:4n-6), eicosapentaenoic acid (C20:5n-3), docosadienoic acid (C22:2n-6), docosapentaenoic acid (C22:5n-3) and docosahexaenoic acid (C22:6n-3) concentrations. The PR group had the highest total PUFA (polyunsaturated fatty acids) content (ca. 8%) and the NR the lowest PUFA content (ca. 6%). The positive group had significantly higher C18:2n-6, C20:3n-6, C20:4n-6, C20:5n-3, C22:5n-3 and C22:6n-3 concentrations in comparison with the negative line. Significant difference in the total PUFA composition was also detected between lines, with the positive line showing a higher concentration (ca. 7%) compared to the negative line (ca. 6%).