Escarificação ácida, temperatura e luz no processo germinativo de sementes de Senna alata (L.) Roxb

O objetivo deste trabalho foi determinar o tempo ótimo de escarificação das sementes de Senna alata em ácido sulfúrico e verificar o efeito da temperatura, em condição de luz e escuro, na germinação de sementes dessa espécie. As sementes foram imersas em ácido sulfúrico concentrado por períodos de 0, 15, 30 e 60 minutos, e o teste de germinação realizado em BOD a 25ºC, utilizando quatro repetições de 50 sementes em cada período de tempo, sendo o delineamento estatístico inteiramente casualizado com 4 tratamentos. No segundo experimento, para verificar o efeito da temperatura e da condição de luz mais adequada a germinação, utilizou-se temperaturas de 10 a 45ºC, com intervalos de 5ºC, em condição de luz fluorescente branca ou escuro contínuo (gerbox preto). Utilizou-se o delineamento experimental inteiramente casualizado, disposto em esquema fatorial 8x2, com 4 repetições, de 50 sementes cada. em todos os testes as avaliações da porcentagem e índice de velocidade de germinação foram feitas diariamente, durante 10 dias, onde as sementes foram consideradas germinadas quando apresentaram 2 mm de raiz. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. A escarificação do tegumento com ácido sulfúrico durante 60 minutos, foi ideal para as sementes de Senna alata, por proporcionar maiores valores na porcentagem e velocidade de germinação. A germinação ocorre entre 15 e 40ºC, sendo consideradas fotoblásticas neutras entre 20 e 40ºC e fotoblásticas negativas preferenciais a 15ºC. O melhor desempenho germinativo foi obtido nas temperaturas de 25, 30 e 35ºC, onde ocorreram maior porcentagem e velocidade de germinação.

The respiratory responses of an amphibious snail Pomacea lineata (spix, 1827), to temperature and oxygen tension variations

1. 1. The respiratory responses of Pomacea lineata to short-term (or acute) exposure to temperature and oxygen tension variations were investigated in animals acclimated to 25°C. 2. 2. The respiratory rates increased with rising temperatures; this increase was sharper between 15 and 25°C than at any other temperature interval; a tendency to a plateau in the RT curve was recorded between 25 and 35°C. 3. 3. All animals survived well to 1 hr exposure to the extreme temperatures used (5 and 40°C). 4. 4. In two different experimental approaches, the animals showed ability to regulate the respiratory rate in declining oxygen tensions, at least down to 10% (70.8 mmHg) oxygen. 5. 5. After 1 hr exposure to hypoxic conditions, P. lineata exhibited the pattern of underpayment of the oxygen debt acquired. 6. 6. Six out of ten animals survived after 40 days in anoxia (100% nitrogen). © 1987.

Efeito do Nível de Energia da Dieta e da Exposição Prévia ao Calor sobre a Respiração Mitocondrial do Músculo Cardíaco de Frangos de Corte

This work was conducted aiming to evaluate the effect of dietary energy level and the previous heat exposure on the respiratory activity of the mitochondria from the cardiac muscle of broiler chickens. It was used broiler chickens (Hubbard) from both sexes and fed with diet containing 2900 kcal ME/kg or 3200 kcal ME/kg. The birds were heat stressed (35°C/4h) in the 1 st, 21 st and 42 nd days of age. The respiratory activity of mitochondria from cardiac muscle was evaluated in a Gilson oxygraph, model 5/6, by using alpha-ceto-glutaric as substrate and the ADP (adenosine-di-phosphate) to stimulate the respiratory activity. There was not effect of dietary energy level and previous heat exposure on the respiratory activity of the mitochondria from cardiac muscle. However, the females presented higher respiratory activity than males. By reason of the low oxidative capability of the heart muscle fiber of the male broiler chickens, these could be more sensitive to cardiac disease than females.

Efeito da temperatura na germina̧ão de sementes de Sebastiania commersoniana (Baillon) Smith & Downs separadas pela colora̧ão do tegumento

Sebastiania commersoniana (Euphorbiaceae) is a tree species of riparian forests in Brazil. Seeds of this species released from mature fruits have heteromorphy in coat colour: dark (dark-brown to black), striated (dark with light-grey stria) and clear (light-grey to whitish). In this work two experiments were carried out in order to study the effect of temperature on seed germination in interaction with coat colour. Germination final percentage and speed index were evaluated. In the first experiment seeds of the three colours were submitted to constant (30°C) and alternating (20-35°C) temperatures. For all the seed colours, best results were obtained at alternating temperature. Physiological quality of striated seeds was greater than those clear seeds and dark seeds were intermediate. In the second experiment striated and clear seeds were submitted to three amplitudes of alternating temperature: 5°C (20-25°C and 25-30°C), 10°C (20-30°C and 25-35°C) and 15°C (20-35°C). Both germination percentage and speed were higher in striated seeds and for the two seed colours, best results were obtained at 20-30°C and 20-35°C. These temperatures are recommended for the germination test.

Rendimento de óleo essencial de Salvia officinalis L. sob ação de reguladores vegetais

This study aimed to evaluate the effect of different plant growth regulators on essential oil yield in Salvia officinalis L. plants. The experiment was held in a greenhouse and the experimental design was completely randomized, with 5 treatments and three replications. The Treatments consisted in the application of gibberellic acid (GA3), benzylaminopurine (BAP), 2-chloroethyl phosphonic acid (ethephon), and Stimulate at 2%, compared with control plants (water). Applications of plant growth regulators were performed in three consecutive periods, in turn, 15, 25 and 35 days after transplanting of seeding germinating in the light at 25°C. The dry mass yield of the aerial part and the oil essential content were determined 131 days after the transplant. The aerial part of the plants was dried in an oven at 35°C; after dry mass determination, the oil was extracted by hydrodistillation and its volume was determined. Plants treated with GA 3 and Stimulate showed increase in essential oil content, while plants treated with BAP and ethephon showed decrease in essential oil volume when compared with the control plants.

Development and validation of HPLC method for quantitative analysis of triamcinolone in biodegradable microparticles

A simple, rapid, selective and specific high performance liquid chromatographic (HPLC) method for quantitative analysis of the triamcinolone in polylactide-co-glycolide acid (PLGA) microparticles was developed. The chromatographic parameters were reversed-phase C18 column, 250mm x 4.6mm, with particle size 5 μm. The column oven was thermostated at 35°C ± 2°C. The mobile phase was methanol/water 45:55 (v/v) and elution was isocratic at a flow-rate of 1 mL.mL-1. The determinations were performed using a UV-Vis detector at 239 nm. The injected sample volume was 10 μL. The standard curve was linear (r2 > 0.999) in the concentration range 100-2500 ng.mL-1. The method showed adequate precision, with a relative standard deviation (RSD) was smaller than 3%. The accuracy was analyzed by adding a standard drug and good recovery values were obtained for all drug concentrations used. The method showed specificity and selectivity with linearity in the working range and good precision and accuracy, making it very suitable for quantitation of triamcinolone in PLGA microparticles.

Production of pectate lyase by penicillium viridicatum RFC3 in solid-state and submerged fermentation

Pectate lyase (PL) was produced by the filamentous fungus Penicillium viridicatum RFC3 in solid-state cultures of a mixture of orange bagasse and wheat bran (1 : 1 w/w), or orange bagasse, wheat bran and sugarcane bagasse (1 : 1 : 0.5 w/w), and in a submerged liquid culture with orange bagasse and wheat bran (3%) as the carbon source. PL production was highest (1,500U mL -1 or 300Ug -1 of substrate) in solid-state fermentation (SSF) on wheat bran and orange bagasse at 96 hours. PL production in submerged fermentation (SmF) was influenced by the initial pH of the medium. With the initial pH adjusted to 4.5, 5.0, and 5.5, the peak activity was observed after 72, 48, and 24 hours of fermentation, respectively, when the pH of the medium reached the value 5.0. PL from SSF and SmF were loaded on Sephadex-G75 columns and six activity peaks were obtained from crude enzyme fromSSF and designated PL I, II, III, IV, V, andVI, while five peaks were obtained fromcrude enzyme fromSmF and labeled PL I', II', III', IV', and VII'. Crude enzyme and fraction III from each fermentative process were tested further. The optimum pH for crude PL from either process was 5.5, while that for PL III was 8.0. The maximum activity of enzymes from SSF was observed at 35°C, but crude enzyme was more thermotolerant than PL III, maintaining its maximum activity up to 45°C. Crude enzyme from SmF and PL III' showed thermophilic profiles of activity, with maximum activity at 60 and 55°C, respectively. In the absence of substrate, the crude enzyme from SSF was stable over the pH range 3.0-10.0 and PL III was most stable in the pH range 4.0-7.0. Crude enzyme from SmF retained 70%-80% of its maximum activity in the acid-neutral pH range (4.0-7.0), but PIII showed high stability at alkaline pH (7.5-9.5). PL from SSF was more thermolabile than that from SmF. The latter maintained 60% of its initial activity after 1 h at 55°C. The differing behavior of the enzymes with respect to pH and temperature suggests that they are different isozymes. Copyright © 2010 Viviani Ferreira et al.

Superação de dormência e influência dos fatores ambientais na germinação de sementes de Spermacoce latifolia

Understanding basic information on weed biology contributes to the implementation of appropriate management and control strategies. Thus, this work was developed to evaluate the germination of Spermacoce latifolia Aubl. seeds, an important weed in reforestation areas. The seeds were subjected to dormancy break treatments, in which the mechanical scarification, chemical treatment (H2SO 4 and KNO 3), heat treatment, and control, were evaluated. Three more tests were done determinate the effects of temperature (10, 15, 20, 25, 30 and 35°C), light filters (absence of light and red, green, yellow, distant red, blue, orange and clear light) and water availability (0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa) on the seeds germination and vigor. The treatments were arranged in a completely randomized design with four replications, and the experimental plot was constituted by gerbox plastic boxes with 50 seeds. The mechanical scarification (sanding) provided the best dormancy break, indicating that Spermacoce latifolia seeds have tegument water impermeability. The seeds showed higher germination percentage under conditions of mild water stress (-0.2 MPa) and the optimal temperature was 25°C. The blue light reduced seed germination.

Efeito da temperatura no desenvolvimento e sobrevivência da cochonilha pseudococcus longispinus (Targioni Tozzetti, 1867) (hemiptera: Pseudococcidae) em cafeeiro

The longtailed mealybug Pseudococcus longispinus (Targioni Tozzetti, 1867) (Hemiptera: Pseudococcidae) has been reported attacking coffee crops causing fruit fall in the State of Minas Gerais, Brazil. The knowledge of the population dynamic of this pest is then necessary to implement control measures. Its development was studied at temperatures of 15, 20, 25, 30 and 35°C, determining the thermal requirements. The insects were confined inside a Petri dish containing a foliar disc of 4 cm diameter of Coffea arabica L., cultivar 'Acaiá Cerrado'. The temperature affected the P. longispinus development and survival. Few insects survived at temperatures of 15 and 30°C, and 100% of mortality was obtained at 35°C. The duration of the nymphal stage was reduced when the temperature was increased from 20 to 25°C, with a survival rate of 80% at both temperatures. The thermal parameters varied according to the development stage of the mealybug and the base temperature was fixed at 8.0 °C for the nymphal stage of females, a thermal constant of 422.1 day degrees and number of generations increased with rising temperature. The optimal temperature for the insect development was 25°C.

Effects of substrate and temperature on the emergence of Phacelia sp. (Boraginaceae) seedling

This study aimed to define the best substrate and temperature for the emergence of Phacelia sp. seedling, annual ornamental flower gardens. The experimental design was entirely randomized in a factorial scheme 37 (three different types of substrates: vermiculite, sand and sphagnum combined with seven temperature conditions: room temperature, constant at 20, 25, 30 and 35C, and alternated at 20-30C and 25-35C) with 4 replications of 100 seeds each. Emergence (%E) and Emergence Rate (ER) were evaluated. The means of the resulting values were then compared by the Tukey test at 5% confidence level. There was a significant interaction amongst substrates and temperatures for all analyzed variables. For seeds sown in vermiculite and sand, the seedlings had higher %E and emerged fastest at 20C, room temperature and 20-30C that did not present statistically significant data. In sphagnum, seedlings showed greater %E in the alternated at 20-30C, room temperature and 20C and emerged quickly at room temperature and 20C that did not present statistically significant data. At room temperature and 20C, the seedlings had higher %E and emerged faster in vermiculite and sand that did not present statistically significant data. At 25, 30 and 25-35C, the seedlings showed better %E and emerged fastest in sand. At 35C, the seedlings showed either in vermiculite and sand were not significantly different in their emergence, but emerged faster in sand. There was not significantly different among substrates in their emergence at 20-30C, but the seedlings emerged faster in vermiculite and sand. It was concluded that the Phacelia sp. seedlings in all substrates showed greater %E at room temperature, 20C and 20-30C. For all temperatures, the seedlings growth parameters were superior when seeds were sown in sand.

Temperature and scarification on seeds germination of copernicia prunifera (Mill) H.E. Moore (Arecaceae)

Copernicia prunifera, known as carnauba, is native to Brazil and presents great potential to be used in gardens and cultivation in pot. Palms species, with relatively few exceptions, can only be propagated by seeds; even so, there are no reports in the literature about the germination of this palm seeds. Several species of the Arecaceae family present seed physical dormancy in varying degrees, demanding treatments to improve germination. The objective of this work was to study the effects of temperature and mechanical scarification on seed germination of C. prunifera. The experimental design was entirely randomized in a factorial arrangement 6 x 2 (six conditions of temperature with or without mechanical scarification) with 4 replications and 25 seeds each. In accordance with the treatment, lateral scarifications were made on the seeds until appearance of the endosperm. Seeds were sown in moist fine vermiculite. Germination (%) and germination rate (GR) were evaluated. Germination data were arcsine (x/100)1/2 transformed before analysis of variance and germination rate data were not transformed. The means of the resulting values were then compared by the Scott-Knott test at 1% confidence level. It was concluded that the biggest germination percentage were obtained at alternated temperature of 25-35°C (92%) and at constant temperature of 25°C (87%). Seeds germinated faster at alternated temperature of 25- 35°C. Germination percentage was similar for the scarified and non-scarified seeds; however, scarified seeds germinated faster.

Seed germination of two Syagrus species native to Brazil

Palm species native to Brazil such as Syagrus picrophylla and S. schizophylla have great ornamental value and for this reason are much demanded for use in landscape. Its propagation is by seeds and often presents considerable problems to nursery managers because their seed has a hard and impermeable shell. Temperature is one of the factors that influence the seed germination process; however, the information for these species is scarce. Thus, this work aimed to study the effects of temperature regimes on the germination of S. picrophylla and S. schizophylla seeds and develop some recommendations in which temperature will obtain high rates of seed germination. The experimental design was entirely randomized with six temperatures and four replications of 25 seeds for each species. Germination and germination rate were evaluated. Higher and faster germination of S. picrophylla and S. schizophylla seeds were verified at constant temperature of 30°C and 35°C; and alternated temperature at 25-35°C.

Propagation of Camptosema grandiflorum native to Brazil by seeds and cuttings

Camptosema grandiflorum Benth., belonging to Fabaceae, is a voluble climber plant native to Brazil. Plants bloom in autumn-winter, producing long and hanging inflorescences with showy red flowers, which are much visited by hummingbirds. The leaves are also attractive, composed by three leaflets. It can be propagated by seeds or cuttings, but both seed germination and cutting rooting percentages are very low. Thus, the objective of this work was to study the effect of different temperatures on seed germination and of different indolebutyric acid (IBA) concentrations on the rooting of cuttings of C. grandiflorum. The experiment was set up at the São Paulo State University, located in Jaboticabal, São Paulo State, Brazil. The germination study was conducted in an entirely randomized design with six different temperatures (constant at 20, 25, 30 and 35°C; and alternated at 20-30 and 25-35°C, with a photoperiod of 12 hours) and four replications of 25 seeds each, placed in plastic boxes with vermiculite. The percentage of germination and the speed germination index (SGI) were evaluated. An entirely randomized block design was adopted for the cutting rooting evaluation, with four IBA concentrations (0; 1,000; 2,000; and 3,000 mg kg-1) and five replications of ten cuttings each, comprising 200 cuttings. After 30 days from the beginning of the rooting experiment, data referring to rooting percentage, number and length of roots and dry weight of roots were collected. For the seed germination experiment, fastest germination and highest germination percentage (87%) were obtained when seeds were maintained under the constant temperature of 30°C. For the cutting experiment, the concentrations of 2,000 and 3,000 mg kg-1 of IBA promoted the highest rooting percentages (98.5 and 94.1%, respectively) and number of roots. There were no statistical differences among the IBA concentrations for length of roots and dry weight of roots.

Effect of temperature on seed germination of ornamental herbaceous perennials

Antirrhinum majus L. and Senecio douglasii DC. are herbaceous perennial ornamental plants used in landscaping. The multiplication of these plants is by seed; however, there are still doubts about the temperature that can provide higher rates and speed of germination. Thus the aim was to study the effect of temperature on seed germination of A. majus and S. douglasii. The study was conducted separately for each species. The experimental design was entirely randomized with six temperature conditions (temperature controlled constant of 20, 25, 30, 35°C and alternating temperatures of 20-30 and 25-35°C with a photoperiod of 12 hours) with four replications of 100 seeds each. Total germination percentage and germination rate were determined. The means were compared by Tukey test at 5%. For A majus the highest germination percentage was observed at 20°C that did not differ statistically from other temperatures. The highest germination rate was obtained at the temperature of 20 and 25°C. For S. douglasii seeds it was observed that the highest germination percentage and germination rate occurred at 20°C. The lower temperature showed the better percentage and germination rate for these species.

Fusarium solani f. sp. passiflorae: A new forma specialis causing collar rot in yellow passion fruit

The aim of this study was to characterize a Fusarium population obtained from yellow passion fruit (YPF) with collar rot using pathogenicity, morphocultural characteristics and molecular tests. Pathogenicity and disease severity were assessed in six plant species: YPF, zucchini, tomato, bean, soya bean and cucumber. Potato dextrose agar medium (PDA) was used to determine mycelial growth at five temperatures (15-35°C). The colour produced by isolates was also determined on PDA at 25°C. Synthetic nutrient agar medium was used to evaluate: (i) type of mycelium and phialides; (ii) size, shape and number of septa from conidia; and (iii) production of chlamydospores and perithecia. Molecular tests consisted of sequencing the ITS-5·8S rDNA region and elongation factor 1α (EF-1α) gene. The isolates caused large lesions on YPF, zucchini and tomato, with YPF having the highest mean disease severity and being the only one that showed wilt symptoms and death of the plant. Thus the isolates showed host specificity. Maximum mycelial growth occurred at 25°C and the predominant colour was bluish-white. The isolates produced long phialides, dense aerial mycelium, oval microconidia with a mean size of 9·5 × 2·6 μm, macroconidia of 32·7 × 3·4 μm with 3·3 septa, and chlamydospores; only one isolate lacked perithecia. Phylogenetic trees of the ITS region and EF-1α gene showed that isolates from YPF formed a distinct group within the F. solani group and the formae speciales of F. solani. It is proposed to name all isolates from YPF as F. solani f. sp. passiflorae. © 2013 British Society for Plant Pathology.