oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress
Costa, Ernany Santos;Bressan-Smith, Ricardo;Oliveira, Jurandi Gon?alves de;Campostrini, Eliemar;Pimentel, Carlos;
Brazilian Journal of Plant Physiology , 2002, DOI: 10.1590/S1677-04202002000200004
Abstract: bean (phaseolus vulgaris l., cv. carioca and cv. negro huasteco) and cowpea plants (vigna unguiculata l. walp cv. epace 10) were grown in a growth chamber with ppf at leaf level of 200 mmol.m-2.s-1 and air temperature 25 + 1 oc. the first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 oc) for 1.5 h. the photochemical efficiency of psii during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 oc, using a modulated fluorimeter. increasing temperature promoted an increase in ff at 45 oc, possibly associated with dissociation of the light harvesting complex from the reaction centre of psii, but a decrease was observed at 48 oc in all cultivars. fmax decreased at 48 oc in carioca and negro huasteco, but not in epace 10, showing a possible correlation between heat tolerance and fmax for this cultivar. the low values of fmax in carioca and negro huasteco indicated a loss of psii activity followed by death of these plants. fv/fmax did not vary in epace 10 but varied in carioca and negro huasteco with increasing temperatures.
Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress  [cached]
Costa Ernany Santos,Bressan-Smith Ricardo,Oliveira Jurandi Gon?alves de,Campostrini Eliemar
Brazilian Journal of Plant Physiology , 2002,
Abstract: Bean (Phaseolus vulgaris L., cv. Carioca and cv. Negro Huasteco) and cowpea plants (Vigna unguiculata L. Walp cv. Epace 10) were grown in a growth chamber with PPF at leaf level of 200 mumol.m-2.s-1 and air temperature 25 + 1 oC. The first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 oC) for 1.5 h. The photochemical efficiency of PSII during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 oC, using a modulated fluorimeter. Increasing temperature promoted an increase in Fphi at 45 oC, possibly associated with dissociation of the light harvesting complex from the reaction centre of PSII, but a decrease was observed at 48 oC in all cultivars. Fmax decreased at 48 oC in Carioca and Negro Huasteco, but not in Epace 10, showing a possible correlation between heat tolerance and Fmax for this cultivar. The low values of Fmax in Carioca and Negro Huasteco indicated a loss of PSII activity followed by death of these plants. Fv/Fmax did not vary in Epace 10 but varied in Carioca and Negro Huasteco with increasing temperatures.
Metodologías para la extracción de virus provenientes de semillas de caraota (Phaseolus vulgaris L.) y frijol (Vigna unguiculata (L.) Walp.).
Pe?a P.,Z.M.; Trujillo,G.;
Revista de la Facultad de Agronomía , 2006,
Abstract: in venezuela from 1980 the presence of pathogenic microorganisms like bacterium, fungi and virus has been indicated in most of the seeds of studied fabaceas, includes: commercial, registered, foundation, experimental; the used methods to guarantee the health of the seed, do not include tests that allow to extract the virus, do not exist registries nor knowledge in general of the introduction of viruses diseases seed borne in our country, in spite of the relevance of this form of transmission. more of 50% of the important diseases in bean (phaseolus vulgaris l.) and in cowpea (vigna unguiculata (l.) walp.) more than 15 virus, seed borne transmission. for that reason, a volume was taken from 53 samples of seeds of bean and cowpea experimental, certified and common type originating of the states aragua, falcón, guárico, lara, portuguesa, and sucre as well as of argentina, chile, colombia, canada and the usa; to be processed in the extraction of virus. two protocols were used for virus extraction: the first one, an observation of viral symptoms in the first fully expanded trifoliate leaf; the second a mechanical inoculation of indicator plants using seed flour. both methodologies confirmed the presence of virus. for bean seeds, 25% of the total experimental type showed viral infection, bean seeds certified 28,6%, bean common 23,1% and 16,6% of the total imported seeds. in cowpea seed, viral infection was detected in common seed (55,5%). the methodologies verify the percentage of viral infection of the material of sowing of different areas from the country and its application will lead to establish controls that prevent the dissemination and use of material with a high viral degree of contamination.
EFEITOS DA éPOCA DE SEMEADURA SOBRE A COMPOSI O QUíMICA E CARACTERíSTICAS FíSICO-QUíMICAS DE GR OS DE CULTIVARES DE Phaseolus Vulgaris L., Phaseolus angularis (willd) Wright E Vigna unguiculata (L.) Walp  [cached]
Alfredo LAM-SANCHEZ,José Fernando DURIGAN,Silvia Leite de CAMPOS,Silvia Regina SILVESTRE
Alimentos e Nutri??o , 2009,
Abstract: RESUMO: Sementes de nove cultivares de feij o-comum (Phaseolus vulgaris, L.) (‘Rio Piquiri’, ‘Rio Tibaji’, ‘Paraná-1’, ‘Catu’, ‘Aysó’, ‘Carioca-80’, ‘Aeté-3’, ‘Moruna-80’ e ‘Aroana-80’), duas de feij o-adzuki (Phaseolus angularis (Willd) (Wright) (‘Adzuki 1’ – vermelha e ‘Adzuki 2’ – verde) e cinco de caupi (Vigna unguiculata (L.) Walp). (‘Epace-1’, ‘Epace-6’, ‘Epace-8’, ‘V-76’ ‘V-245’) foram obtidas de 3 épocas de plantio (“águas I” – 26/11/82; “seca” – 07/04/83; “águas II” – 27/09/83 e avaliadas quanto à composi o química e características de hidrata o e cozimento. As características foram significativamente influenciadas pela época de semeadura. Os feij es produzidos na época “águas II” apresentaram valores protéicos significativamente mais elevados do que os das outras duas, e o teor médio foi de 20,75; 16,45 e 23,10 g/100g para o feij o-comum, o adzuki e o caupi, respectivamente. O conteúdo de óleo de feij o comum (1,38 g/100g) correlacionou-se negativamente com o de proteína (-0,64). O de cinzas apresentou o mesmo comportamento que o de proteína quanto às épocas de cultivo, o que n o aconteceu com o de carboidratos. As maiores sementes foram produzidas pela época “águas II” e pelo feijoeiro-comum (20,38 g/100 sementes) com destaque para os cvs, Moruna-80, Paraná-1, e Carioca-80. Para o caupi este valor foi de 19,48g e para o adzuki, de 7,79g. Os gr os cultivados nas épocas “águas I” e “águas II” apresentaram melhor hidrata o (RH = 1,94), e estes os maiores conteúdos de gr os “hardshell”, com destaque para os cvs. Carioca-80 (7,4%), Adzuki-1 (14,2%), Aysó (19,5%), Epace- (19,5%) e V-245 (31,0%). O tempo de cozimento foi maior para os gr os produzidos na época “águas I” e, dentre os cultivares, os de Vigna foram os que apresentaram os menores tempos, nas três épocas (13,17 minutos), quando comparados com os de feij o-comum (25,47 minutos) e de feij o-adzuki (104,10 minutos). PALAVRAS–CHAVE: Feij o-comum; feij o-adzuki; caupi; épocas de cultivo; composi o química; hidrata o; cozimento.
Marcha de absor??o do nitrogênio do solo, do fertilizante e da fixa??o simbiótica em feij?o-caupi (Vigna unguiculata (L.) walp.) e feij?o-comum (Phaseolus vulgaris L.) determinada com uso de 15N
Brito, Marciano de Medeiros Pereira;Muraoka, Takashi;Silva, Edson Cabral da;
Revista Brasileira de Ciência do Solo , 2009, DOI: 10.1590/S0100-06832009000400014
Abstract: common bean (phaseolus vulgaris l.) and cowpea (vigna unguiculata (l.) walp.) are among the main sources of plant protein for a large part of the world population, mainly that of low income, and nitrogen is the main constituent of these proteins. the objectives of this study were to evaluate, through the 15n-dilution technique and using rice and non-nodulating soybean as control plants, the relative contributions of nitrogen sources (symbiotically fixed n, soil native n and fertilizer n) on the growth of common bean and cowpea and to compare the isotopic technique (id) with the difference methods (dm) for the evaluation of symbiotic n2 fixation. the study was carried out in a greenhouse of the center for nuclear energy in agriculture - cena/usp, sao paulo state, brazil, using 5 kg pots with a typic haplustox (dystrophic red-yellow latosol). the experiment was arranged in completely randomized blocks, with 16 treatments and three replications, in an 8 x 2 factorial design. the treatments were eight sampling times: 7, 24, 31, 38, 47, 58, 68 and 78 days after sowing (das) and two crops: common bean and cowpea. an n rate of 10 mg kg-1 soil was used, as urea, enriched with an excess of 10 % of 15n atoms. symbiotic n fixation supplied the bean and cowpea plants with the greatest amount of accumulated n, followed, in decreasing order, by soil and fertilizer. the highest rate of n symbiotic fixation was observed at the pre-flowering growth stage of the bean and cowpea plants. after the initial growth stage, 24 das, rice and non nodulating soybean were appropriate control plants to evaluate symbiotic n fixation. there was a good agreement between id and dm, except in the initial growth stage of the crops.
Detection and validation of single feature polymorphisms in cowpea (Vigna unguiculata L. Walp) using a soybean genome array
Sayan Das, Prasanna R Bhat, Chinta Sudhakar, Jeffrey D Ehlers, Steve Wanamaker, Philip A Roberts, Xinping Cui, Timothy J Close
BMC Genomics , 2008, DOI: 10.1186/1471-2164-9-107
Abstract: Here we report detection and validation of SFPs in cowpea using a readily available soybean (Glycine max) genome array. Robustified projection pursuit (RPP) was used for statistical analysis using RNA as a surrogate for DNA. Using a 15% outlying score cut-off, 1058 potential SFPs were enumerated between two parents of a recombinant inbred line (RIL) population segregating for several important traits including drought tolerance, Fusarium and brown blotch resistance, grain size and photoperiod sensitivity. Sequencing of 25 putative polymorphism-containing amplicons yielded a SFP probe set validation rate of 68%.We conclude that the Affymetrix soybean genome array is a satisfactory platform for identification of some 1000's of SFPs for cowpea. This study provides an example of extension of genomic resources from a well supported species to an orphan crop. Presumably, other legume systems are similarly tractable to SFP marker development using existing legume array resources.Cowpea (Vigna unguiculata L. Walp) is grown extensively as a food and fodder crop in West Africa, lower elevation areas of eastern and southern Africa, north-eastern Brazil, parts of the Middle East, India, and the south-eastern and south-western regions of North America [1]. Like common beans (Phaseolus vulgaris L.) which are combined with maize or other starchy staple crops in other parts of the world, dry grain cowpea is consumed with lower protein cereal and root/tuber staples to provide an adequate protein quantity and quality to hundreds of millions of rural and urban consumers in West Africa [2,3]. Cowpea forage is used for livestock and cowpea hay plays a critical role as fodder during the dry season in West Africa [4]. 'Longbean' or 'Asparagus bean' of cowpea cultivar group Sesquipedialis is considered one of the top-ten Asian vegetable crops and is grown on at least 400,000 hectares worldwide for production of fresh 'green' or 'snap' beans.Cowpea (2n = 2x = 22) with genome size ~600 Mb be
Effectiveness and efficiency of chemical mutagens in cowpea (Vigna unguiculata (L.) Walp)
D Dhanavel, P Pavadai, L Mullainathan, D Mohana, G Raju, M Girija, C Thilagavathi
African Journal of Biotechnology , 2008,
Abstract: A study was undertaken in a cowpea (Vigna unguiculata (L.) Walp.) variety CO 6 to assess the efficiency and effectiveness of chemical mutagens; ethyl methane sulphonate (EMS), diethyl sulphate (DES) and sodium azide (SA). EMS treatments were found highly effective than the other chemicals. Mutagenic effectiveness and efficiency decreased with increase in all mutagenic treatments.
Plants regeneration from African cowpea variety (Vigna unguiculata L. Walp.)
MS Diallo, A Ndiaye, M Sagna, YK Gassama-Dia
African Journal of Biotechnology , 2008,
Abstract: Vigna unguiculata (L.) Walp. plant was efficiently regenerated from cotyledonary node explants. The shoots multiplication rate was influenced by the presence or the absence of cotyledons. Explants with two entire cotyledons from 5-6-d-old seedling produced the greater number of shoots (8.30) after two weeks on B5 medium supplemented with 1 mg.l-1 BAP. Shoots elongation is optimal on media supplemented with kinetin. Rooting is improved after an induction phase on half strength MS, producing 95.83% of rooted plants. No confined atmosphere surrounding plantlets is essential for survival during acclimatization. The regenerated plants flowered and produced pods and viable seeds.
Floral Biology and Pollination Ecology of Cowpea (Vigna Unguiculata L. Walp)  [cached]
Ige, O. E.,Olotuah, O.F,Akerele, V.
Modern Applied Science , 2011, DOI: 10.5539/mas.v5n4p74
Abstract: Studies on the floral biology and pollination ecology of three varieties of cowpea (Vigna unguiculata L. Walp) were carried out. The varieties studied were Var. Oloyin, Var. Sokoto, and Var. Drum. Cowpea is a self pollinated crop which is encouraged by the arrangements of the floral parts. However, Insects visiting cowpea flowers have been implicated in the movement of pollen from one cowpea plant to another. Flower opening of cowpea begins between 6:00am and 6:30am and closes between 11:30am and 12:00pm. Pollen analysis showed similarities in the pollen morphology of the cowpea varieties. Moreover Var. Drum produced the highest number of pollen grains per flower in terms of pollen productivity.
Targeted mutagenesis in Vigna unguiculata (L.) Walp. and Cucumeropsis mannii (NAUD) in Nigeria
GC Obute, BC Ndukwu, OF Chukwu
African Journal of Biotechnology , 2007,
Abstract: The mutagenic effects of 0.2% aqueous solution of colchicine on gross and micromophological features of seedlings of Vigna unguiculata (L) Walp. and Cucumeropsis mannii (Naud.) were investigated. Terminal buds of two-week old seedlings were assaulted with 0.2% colchicine by the cotton plug and micro syringe methods and performances were monitored until maturity. Colchicine-treated V. unguicu-lata seedlings were observed to grow slower, had malformed leaves, flowered late and produced less number of seeds per pod than the control. Mean values of features like stomatal indices on both the abaxial and adaxial surfaces, terminal leaflet dimensions and trichome distribution between the treated and control were found to be significantly different. In contrast, treated seedlings of C. mannii flowered and fruited earlier than the case of control material. However, growth was also slowed down by the treatment while features like stomatal indices and trichome distribution were not significantly different. The results here have shown that apart from doubling of chromosomes, colchicine can also be used to induce other mutagenic changes which may be of agronomic utility.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.