185 resultados para Chondrilla-juncea
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p.161-171
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The biology and phenology of the eriophyid mite, Floracarus perrepae Knihinicki and Boczek,a potential biological control agent of Lygodium microphyllum (Cav.) R. Br., was studied in its native range - Queensland, Australia. F. perrepae forms leaf roll galls oil tile subpinnae of L. microphyllum. It has a simple biology, with females and males produced throughout the year. Tile Population was female biased at 10.5 to 1. The immature development time was 8.9 ± 0.1 and 7.0 ± 0.1 days; adult longevity was 30.6 ± 1.6 and 19.4 ± 1.2 days and mean fecundity per female was 54.5 ± 3.2 and 38.5 ± 1.6 eggs at 21 and 26 ° C, all respectively. Field studies showed that tile mite was active year round, with populations peaking when temperatures were cool and soil moisture levels were highest. Two species of predatory mites, Tarsonemus sp. and a species of Tydeidae, along with the pathogen Hirsutella thompsonii, had significant effects oil all life stages of F. perrepae. Despite high levels of predators and the pathogen, F. perrepae caused consistent damage to L. microphyllum at all the field sites over the entire 2 years of the study.
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褪黑激素(N-乙酰基-5-甲氧基色胺)是一种广泛存在于生物体内的吲哚类活性分子。本文以野芥菜(Brassica juncea)为例,初步研究了外源褪黑激素对植物生长生殖的影响。我们选取了发芽2天和发芽4天的野芥菜幼苗,用不同浓度的褪黑激素对其处理24小时,然后测量根的伸长量。结果表明,对于发芽2天的野芥菜,0.1 µM的外源褪黑激素能够显著提高野芥菜幼苗根的生长,而100 µM的外源褪黑激素处理则能够显著抑制根的生长;对于发芽4天的野芥菜,低浓度的外源褪黑激素处理对根生长的影响不明显,而高浓度的褪黑激素处理(如100 µM)能够显著抑制根的伸长。结果表明发芽晚期的野芥菜幼苗的根可能对褪黑激素的处理不敏感。由于褪黑激素对植物的生理作用类似于生长素的作用,因此选用了发芽2天的野芥菜幼苗为植物材料,用外源褪黑激素处理其根24小时后,通过间接酶联免疫吸附测定(ci-ELISA)的方法测定了内源吲哚乙酸(IAA)含量的变化。结果表明低浓度的褪黑激素处理时,内源IAA的含量增高,而在高浓度的褪黑激素处理时,内源IAA含量的变化不大。 关于褪黑激素对野芥菜生殖的影响,我们在花蕾期用褪黑激素涂抹野芥菜的花蕾,并在开花授粉后用褪黑激素涂抹柱头,然后在结实时测量果荚长度,种子千粒重,平均每荚种子数,发芽率等指标。结果表明:对于在花蕾期用褪黑激素处理的植株来说,褪黑激素处理对其的果荚长度,千粒重,平均每荚种子数都没有显著的影响。对于开花后用褪黑激素处理授粉后的柱头,1 µM的褪黑激素处理过的主枝具有较长的果荚长度,而褪黑激素处理对千粒重,平均每荚种子数,发芽率,发芽势和发芽指数均没有显著的影响。在花粉萌发实验中,外源褪黑激素的处理浓度和时间均对花粉萌发有一定的影响,表现为随时间的增加,花粉萌发数目增加,在4 h时,低浓度的褪黑激素处理(10 µM)下花粉的萌发较多。
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Tesis (Maestría en Ciencias con Orientación en Procesos Sustentables) UANL, 2010.
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This study investigates the effects of temperature and pressure on inactivation of myrosinase extracted from black, brown and yellow mustard seeds. Brown mustard had higher myrosinase activity (2.75 un/mL) than black (1.50 un/mL) and yellow mustard (0.63 un/mL). The extent of enzyme inactivation increased with pressure (600-800 MPa) and temperature (30-70 °C) for all the mustard seeds. However, at combinations of lower pressures (200-400 MPa) and high temperatures (60-80 °C), there was less inactivation. For example, application of 300 MPa and 70 °C for 10 minutes retained 20%, 80% and 65% activity in yellow, black and brown mustard, respectively, whereas the corresponding activity retentions when applying only heat (70 °C, 10min) were 0%, 59% and 35%. Thus, application of moderate pressures (200-400 MPa) can potentially be used to retain myrosinase activity needed for subsequent glucosinolate hydrolysis.
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Knowledge of the leaf area plant are needed for agronomic and physiological studies involving plant growth. The aim of this study was to obtain a mathematical model using linear measures of leaf dimensions, which will allow the estimation of leaf area of Crotalaria juncea L. Correlation studies were conducted involving real leaf area (Sf) and leaf length (C), maximum leaf width (L) and the product between C and L. All tested models (linear, exponential or geometric) provided good estimation of leaf area (above 87%). The better fit was attained using linear model, passing or not through the origin. From a practical viewpoint, it is suggested to use the linear model involving the C and L product, using a linear coefficient equal to zero. Estimation of leaf area of Crotalaria juncea L. can be obtained using the model Sf = 0.7160 x (C*L) with a determination coefficient of 0.9712.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The objective of this study was to evaluate the effect of glyphosate applied alone and in mixtures with 2.4-D or metsulfuron methyl in the desiccation of mature plants of Crotalaria juncea during the fall season, in a field crop. Two experiments were carried out using a randomized experimental block design, in a 4 × 3 factorial scheme, with four replications. Treatments in the first experiment were formed by four doses (0.00, 0.54, 1.08 and 1.62 kg ha -1) of glyphosate, associated with three doses (0.00, 0.806 and 1.209 kg ha -1) of 2 , 4-D. In the second experiment the same doses of glyphosate were studied associated with three doses (0.0 4.0 and 8.0 g ha -1) of metsulfuron-methyl. Visual evaluations of plant poisoning, score number of plants with regrowth and dry matter of plants were determined. It was concluded that glyphosate applied alone or in association with 2.4-D or metsulfuron-methyl, regardless of the applied doses, was ineffective in the desiccation of mature plants of Crotalaria juncea.
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The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver megalocytosis in the donkeys ingesting 0.6 and 1g/kg/day. Two other donkeys that received daily doses of 3 and 5g seed/kg showed initial respiratory signs 70 and 40 days after the start of the administration, respectively. The donkeys were euthanized following severe respiratory signs and the main lung lesions were proliferation of Clara cells and interstitial fibrosis. Three donkeys ingested seeds of C. retusa containing 5.99% of monocrotaline at daily doses of 0.025, 0.05 and 0.1g/kg for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was moderate liver megalocytosis in each of the three donkeys. One donkey that received a single dose of 5g/kg of C. retusa seeds and another that received 1g/kg daily for 7 days both showed severe clinical signs and died with diffuse centrilobular liver necrosis. No lung lesions were observed. Another donkey that received a single dose of 2.5g/kg of C. retusa seeds showed no clinical signs. The hepatic and pneumotoxic effects observed are consistent with an etiology involving DHPAs. Furthermore, the occurrence of lung or liver lesions correlates with the type of DHPAs contained in the seeds. Similarly as has been reported for horses, the data herein suggest that in donkeys some DHPAs are metabolized in the liver causing liver disease, whereas others are metabolized in the lung by Clara cells causing lung disease. © 2013 Elsevier Ltd.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)