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Mohamed Mahgoub Azooz,*, Ashraf Mohamed Youssef and Parvaiz Ahmad
Abstract: Exogenously applied salicylic acid has been shown to be an essential signal molecule involved in both local defense reactions and induction of systemic resistance response of plants after salt stress. Our study was aimed at evaluating the foliar spray with different levels (0.0, 0.5 and 1.0 mM) of salicylic acid (SA) on broad bean (Vicia faba L) seedlings grown under diluted seawater on growth and some related physiological responses. Seawater irrigation negatively affected growth parameters, free amino acids and K+, while the contents of soluble sugars and protein, proline, Cl , Na+, ion leakage, lipid peroxidation and antioxidant enzyme activities were significantly increased. Foliar spray with SA improved all growth parameters and increases the activities of antioxidant enzymes. On the other hand, plants treated with SA had lower Cl and Na+, while K+ had a reverse pattern. Based on our findings, the effectiveness of SA in inducing seawater stress tolerance depends upon the concentration of SA applied. The inducer effect of SA was greater with 1 than 0.5 mM treatment. This effect includes the stimulation of antioxidant enzyme activities and regulation of osmotic adjustment through accumulation of osmotic solutes and regulation of absorption and distribution of inorganic ions.[...] Read More.
Keywords: Antioxidant enzyme activities, inorganic ions, proline.
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文章
Law-Ogbomo, K. E.*, Remison, S. U. and Jombo, E. O.
Abstract: A field study was conducted at the Teaching and Research Farms of the University of Benin, Benin City, Nigeria in 2007 and 2008 to evaluate the effect of palm oil mill effluent and NPK fertilizer on the performance of Amaranthus cruentus. The trial involved three levels of palm oil mill effluent (0. 5 and 10 t ha-1) and three levels of NPK (0, 150 and 300 kg ha-1) using a factorial arrangement fitted into randomized complete block design and replicated three times. Results revealed that the effluent and NPK fertilizer had positive effects on dry matter partitions, relative yield, relative agronomic effectiveness and chlorophyll content of A. cruentus. Integration of 5 t POME and 300 kg NPK ha-1 had the optimum total dry matter (9.65 t ha-1), relative yield (2.08), relative agronomic effectiveness (1.91) and total chlorophyll content (58.80 mg g-1).[...] Read More.
Keywords: Amaranthus cruentus, chlorophyll content, dry matter, relative agronomic, effectiveness.
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文章
Ahmad Khan* and Shad Khan Khalil
Abstract: An area of plant science that is still unexplored is how leaf area affects crop dry matter production due to aeration of seed in osmoticum. In view of this, an experiment was conducted at Agricultural Research Farm of NWFP Agricultural University, Peshawar, Pakistan in the summer of 2003 and repeated in 2004. The seeds of two mung bean cultivars (NM-92 and NM- 98) were primed, some for 6 h and others for 12 h in using either distilled water (0MPa osmotic potential) or Polyethylene glycol-8000 (PEG) solution having -0.2, -0.5 and -1.2 MPa osmotic potential. A control treatment (dried seeds) was also included in the experiment. The primed seed were dried back, till the weight become constant and were store for sowing at 25°C. Data was collected on mung bean leaf area, dry matter production and growth parameters at different growth stages. Seed moisture content at maturity stage was also determined. There was no significant difference in leaf area for the different cultivars and seed treatment duration also did not lead to a significant difference in leaf area. However, seed priming techniques significantly affected the measured parameters. Dried seed had developed lower leaf area and dry matter compared to primed seeds. An exponential linear model of leaf area and total dry matter revealed that dry matter production was linearly related to leaf area (r2 = 77.23). The linear relationship between the leaf area and dry matter hold true our hypothesis and thus we concluded that beside environmental and genetical factors, the dry matter production is a function of leaf area in aerated seed of mung bean crop in semi-arid areas like North western Pakistan.[...] Read More.
Keywords: Mung bean, priming, growth, dry matter and leaf area.
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O. O. Oyedapo*, B. A. Akinpelu, K. F. Akinwunmi, M. O. Adeyinka and F. O. Sipeolu
Abstract: Anti-inflammatory activity of extract of Lantana camara, Linn and its fractions was investigated using stabilization of red blood cell membrane lysing technique. Phytochemically, whole plant extract (WPE) and ethanol fraction (EF) gave positive reactions for the presence of saponins, tannins, flavonoids and cardiac glycosides. The ethyl acetate fraction (EAF) gave reactions for the presence of flavonoids while butanol fraction (BF) gave positive test for the presence of saponins. The percentage membrane stability exhibited by the extract and various fractions was concentration dependent and compared favorably with those of standard drugs (Ibuprofen and Indomethacin). The results revealed that both ethanol and ethyl acetate fractions contained principles that protected the erythrocyte membranes effectively. Moreover, ethyl acetate fraction provided highest protection against induced lyses and exhibited both monophasic and biphasic responses at all the concentrations assayed. The possible mechanism of action of the extract and fractions is described and discussed.[...] Read More.
Keywords: Membrane, stabilization, anti- inflammatory, Lantana camara.
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Kumar Arun*, P. C. Mali and V. K. Manga
Abstract: Downy mildew or green ear disease of pearl millet caused by Sclerospora graminicola is the most destructive disease. Affected plants produce green ear with various types of proliferations and malformation of the panicle. Deranged physiology of susceptible and resistant varieties is governed by genetic base, pathogen virulence and induced resistance. Phenolic compounds have been noticed most influential secondary products in determination of resistance in pearl millet plants. In relation to this, activities of polyphenol oxidase (PPO), peroxidase (POX), catalase (CAT) and IAA oxidase (IAAO) have also been found deranged considerably in the downy mildew affected plants of susceptible and resistant cultivars. The study suggests that accumulation of total phenols and OD-phenols caused the hyperphenolicity in infected resistant host tissues despite increased activities of POX and PPO. Total amino acids and free proline contents were increased manifold (1222.2 and 942.6%, respectively) in diseased tissues, particularly in resistant cv. HHB 67 than in susceptible one (Eknath), indicating biotic stress caused by S. graminicola. The role of enzyme activities and their related compounds have been discussed in the present paper.[...] Read More.
Keywords: Pearl millet, downy mildew, Sclerospora graminicola, metabolites, oxidative enzymes, hyperphenolicity.
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O. Nwaichi Eucharia* and O. Ayalogu Edward
Abstract: A twelve-week study was undergone to identify selective effects of Mucuna on companion crop plant and to screen Mucuna for capacity to suppress weeds. A 10% (v/w) contamination with Nigerian Bonny light crude oil was simulated for stress tolerance assessment. Mucuna pruriens supported revegetation, soil and water conservation and also contains potentially toxic BTEX and PAHs that are not phytotoxic to itself but suppressed the growth of Sphenostylis stenocarpa and inhibited the growth of weeds. The detrimental influence on crop plant could be linked to the interactions between soil microorganisms and plants at the rhizophere and this conferred competitive advantage on Mucuna. Physiological and environmental stress induced by hydrocarbon contamination, affected the growth performance of Mucuna and decreased the amount of these toxic compounds released. Comparable amount of toxic hydrocarbons were found in Mucuna grown in uncontaminated treatments confirming its natural composition. Growth indices measured as plant height, leaf area and dry weight, confirmed allelopathic suppression on crops. Allelopathic chemicals persisted in some neighbouring plants as those planted in succession. Although produced allelochemicals acted as herbicides, it may also have undesirable effects on non-target species thus the need for prior ecological studies.[...] Read More.
Keywords: Allelopathy, contamination, germination, growth, interplant, Mucuna, toxicity, weed.
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Acharya Laxmikanta, * and Chandra Panda Pratap
Abstract: Random amplified polymorphic DNA (RAPD), Inter simple sequence repeat (ISSR) and Amplified fragment length polymorphism (AFLP) markers were used to verify the segregation of the genus Cassia L. (sens. lat.) into three distinct genera namely, Chamaecrista Moench., Senna P. Mill. and Cassia L. (sens.str.). Eighteen representatives of the three taxa were characterized using the molecular markers. 25 RAPD, six ISSR primers and six AFLP primer combinations resulted in the amplification of 612, 115 and 622 bands (loci), respectively. Most of the loci are found to be polymorphic, showing high degrees of genetic diversity among the different taxa studied. The dendrogram constructed on the basis of the RAPD, ISSR and AFLP data using the SHAN clustering, divided Cassia L. (sens. lat.) into three different clusters as Chamaecrista Moench., Senna P. Mill. and Cassia L. (sens.str.). High bootstrap value revealed that all the clusters were stable and robust. It was observed from the present investigation that these genera have their identity at molecular level, which supports the elevation of the genus Cassia L. sens. lat. to the level of sub tribe Cassiinae and segregation into three distinct genera instead of intra-generic categories. In the present study taking the molecular markers into account the trifurcation of the sub tribe Cassiinae could be re-established.[...] Read More.
Keywords: Cassia, molecular phylogeny, RAPD, ISSR, AFLP.
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文章
Manoj Kumar Bisoyi, Laxmikanta Acharya, Arup Kumar Mukherjee, * and Pratap Chandra Panda
Abstract: Six species of Sesbania were fingerprinted using RAPD and ISSR markers. Both markers yielded a total of 249 bands out of which 243 were polymorphic in nature indicating high degrees of genetic diversity in the genus. Cluster analysis using the combined data revealed segregation of the lone species Sesbania grandiflora from the rest of the species. High boot strap values in the dendrograms show the accuracy and authenticity of the result. All other five species got separated to a distinct cluster. This supports the taxonomic division of the genus Sesbania into Agati Desv. comprising the only species S. grandiflora (Linn.) Poir. and sub-genus Eusesbania Baker containing all other species.[...] Read More.
Keywords: Sesbania, RAPD, ISSR and phenogram.
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文章
Dechassa Duressa*, Khairy Soliman and Ernst Cebert
Abstract: It is well documented that aluminum (Al) toxicity is the most important constraint of crop production on acid soils. Chelation of Al in the rhizosphere with root secreted organic acid anions is a common mechanism of Al tolerance in most plants including soybean. Phenolic substances are recently implicated as additional physiological mechanism of plant Al tolerance. This study was undertaken to investigate the role of phenolics in soybean Al tolerance and to examine protein expression changes in soybean roots under Al stress. An Al-tolerant soybean genotype PI 416937 and Al-sensitive Young were used in the study. Protein and polyphenol profile changes in response to Al stress, were examined in roots tips of hydroponically grown plants 72 h post treatment. Al significantly increased total phenol exudation from roots of the Al tolerant genotype PI 416937, whereas, flavonoid content did not vary with treatment. Al also altered the expression level of several proteins in genotypic and non genotypic specific manner. This is the first study to show that polyphenol is involved in soybean Al tolerance. Future research should consider quantification of individual flavonoid compounds in root tissue as well as culture solution, and sequencing and functional annotation of Al regulated proteins.[...] Read More.
Keywords: Soybean, aluminum tolerance, protein expression, phenolics.
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文章
Eréndira J. Cohen-Fernández*, Francisco F. Pedroche, Mónica Rodríguez Palacios, Sergio Álvarez Hernández and Esther Meave del Castillo
Abstract: A phylogenetic analysis of the Prorocentrum species is presented, that includes the sequences of the large and small ribosomal RNA subunits from 19 cultures from 13 of the 20 species reported in the Pacific coast of Mexico; the results showed that P. micans, P. gracile and P. mexicanum were the closest of species, that planktonic may be more recent than epibenthonic species and it is suggested that the probable ancestor of the Prorocentrum genus could be a round cell without apical spine, toxic and epibenthonic.[...] Read More.
Keywords: Prorocentrum, parsimony analysis, dinoflagellates, LSUrDNA, SSUrDNA.
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