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Sample records for catenulata sobre zea

  1. Efecto del Almacenamiento de Granos de Maíz (Zea mays) sobre la Calidad del Aceite Extraído Effect of Grains of Maize (Zea mays) Storage on the Quality of the Extracted Oil

    OpenAIRE

    Carlos Hernández; Ysamar Rodríguez; Zulay Niño

    2009-01-01

    Se evaluó el efecto del almacenamiento de granos de maíz amarillo (Zea mays) sobre la calidad del aceite obtenido del mismo. Se determinaron los parámetros de calidad del maíz al momento de la recepción, los índices de acidez, peróxido, y el color del aceite extraído de granos almacenados en un silo de concreto por 0, 30, 60 y 90 días, utilizando los procedimientos descritos en las normas vigentes en Venezuela. Se encontró un efecto adverso significativo (P

  2. A Perilipin Gene from Clonostachys rosea f. Catenulata HL-1-1 Is Related to Sclerotial Parasitism

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    Zhan-Bin Sun

    2015-03-01

    Full Text Available Clonostachys rosea f. catenulata is a promising biocontrol agent against many fungal plant pathogens. To identify mycoparasitism-related genes from C. rosea f. catenulata, a suppression subtractive hybridization (SSH cDNA library of C. rosea f. catenulata HL-1-1 that parasitizes the sclerotia of S. sclerotiorum was constructed. 502 clones were sequenced randomly, and thereby 472 expressed sequence tags (ESTs were identified. Forty-three unigenes were annotated and exhibited similarity to a wide diversity of genes. Quantitative real -time PCR showed that a perilipin-like protein encoding gene, Per3, was up-regulated by 6.6-fold over the control at 96 h under the induction of sclerotia. The full-length sequence of Per3 was obtained via 5' and 3' rapid identification of cDNA ends. Overexpression of Per3 in HL-1-1 significantly enhanced the parasitic ability on sclerotia. The results indicated that Per3 might be involved in the mycoparasitism of C. rosea f. catenulata HL-1-1. This is the first report of a perilipin as a potential biocontrol gene in mycoparasites. The study provides usefu l insights into the interaction between C. rosea f. catenulata and fungal plant pathogens.

  3. Efecto del Almacenamiento de Granos de Maíz (Zea mays sobre la Calidad del Aceite Extraído Effect of Grains of Maize (Zea mays Storage on the Quality of the Extracted Oil

    Directory of Open Access Journals (Sweden)

    Carlos Hernández

    2009-01-01

    Full Text Available Se evaluó el efecto del almacenamiento de granos de maíz amarillo (Zea mays sobre la calidad del aceite obtenido del mismo. Se determinaron los parámetros de calidad del maíz al momento de la recepción, los índices de acidez, peróxido, y el color del aceite extraído de granos almacenados en un silo de concreto por 0, 30, 60 y 90 días, utilizando los procedimientos descritos en las normas vigentes en Venezuela. Se encontró un efecto adverso significativo (PThe effect of storage time on grains of yellow maize (Zea mays was evaluated on the quality of the oil obtained. The quality parameters detected at the reception of the maize were: indexes of acidity, peroxide and the color of the oil extracted from grains stored in a concrete silo for 0, 30, 60 and 90 days, using the procedures described in the patterns in Venezuela. Adverse significant effects (P<0.05 of the storage time on the indexes analyzed were found. These were caused by the moisture and impurities of the grains, as well as a deficiency of 704 m³ min-1 of fresh air fed to the silo, which affects storage. The grain of maize stored during 90 day produced increases in the index of acidity, index of peroxide and color of the extracted oil.

  4. Estudio de la irritación ocular y dérmica de Pochonia chlamydosporia var. catenulata

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    L. García

    2004-01-01

    Full Text Available Pochonia chlamydosporia var. catenulata, cepa Vcc 108 es un agente eficaz en el control de Meloidogyne spp. Para determinar el potencial de irritación dérmica y ocular se emplearon los métodos in vivo descritos por la Agencia de Protección Ambiental (EPA y dos ensayos in vitro como alternativos a irritación ocular, el método de la membrana corioalantoidea del huevo de gallina (HET-CAM y el ensayo cuantitativo con tinción de azul de tripán (CAM-TBS. En los estudios in vitro se aplicaron cuatro concentraciones del hongo vivo e inactivado y en los in vivo se emplearon dosis límite. Aunque cada método utiliza diferentes categorías de irritación, en todos los ensayos Pochonia chlamydosporia var. catenulata se clasificó como No irritante dérmico y ocular

  5. Interação entre herbicida e inseticida sobre o milho-pipoca (Zea mays, as plantas daninhas e a lagarta-do-cartucho Interaction between herbicide and insecticide on popcorn (Zea mays, weeds and fall armyworm

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    A.A. Silva

    2007-03-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da mistura de herbicidas nicosulfuron + atrazine e o inseticida chlorpirifos sobre o cultivar de milho-pipoca UFVM2, as plantas daninhas e a lagarta-do-cartucho. Utilizou-se o delineamento experimental de blocos completos ao acaso, em esquema fatorial (5x2+3, com quatro repetições. O primeiro fator foi constituído pelas doses de nicosulfuron (0, 10, 20, 30 e 40 g ha-1 + atrazine (1.200 g ha-1 + óleo mineral (900 g ha-1 e o segundo pelas doses do inseticida chlorpirifos (0 e 240 g ha-1. Foram avaliados três tratamentos adicionais: duas testemunhas, com e sem capina, ambas sem inseticida, e uma testemunha com capina e com inseticida. Não se observou interação significativa entre doses de nicosulfuron e do chlorpirifos no controle da lagarta-do-cartucho. A mistura no tanque formada pelo chlorpirifos com os herbicidas promoveu intoxicação às plantas de milho-pipoca, principalmente nas maiores doses do nicosulfuron (20, 30 e 40 g ha-1. O chlorpirifos não interferiu na eficiência de controle de plantas daninhas pelos herbicidas nem no estande final, no número de espigas por planta, no rendimento e na capacidade de expansão dos grãos de milho-pipoca.This study aimed to evaluate the effect of the tank-mixture herbicide nicosulfuron combined with the insecticide chlorpirifos on the popcorn cultivar UFVM2, weeds and fall armyworm. The experiment was arranged in a randomized complete block design, in a (5x2+3 factorial scheme and four replications. The first factor consisted of nicosulfuron doses (0, 10, 20, 30, and 40 g ha-1 + atrazine (1.200 g ha-1 + oil (900 g ha-1 and the second of doses of the insecticide chlorpirifos (0 and 240 g ha-1. Three additional treatments were evaluated: two controls, with and without weeding, both without insecticide, and one control with weeding and insecticide. The interaction between the nicosulfuron and chlorpirifos doses in the control of the fall armyworm

  6. Efectos de extractos acuosos de la maleza Cyperus rotundus L. (Cyperaceae sobre la germinación de semillas y crecimiento de plántulas de maíz ( Zea mays L. cv. Pioneer 3031

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    José A. Laynez Garsaball

    2013-04-01

    Full Text Available La investigación tuvo por fi nalidad determinar los efectos de extractos acuosos del follaje de Cyperus rotundus L. sobre la germinación de semillas y el crecimiento de plántulas de maíz ( Zea mays L. cv. Pioneer 3031. Un primer extracto al 15% p/v fue preparado con el follaje de plantas mays L. cv . Pioneer 3031. Un primer extracto al 15% p/v fue preparado con el follaje de plantas mays de C. rotundus de 15 días, se dejó reposar por 48 h y luego se obtuvo por dilución extractos al 0; 2,0; 4,0 y 6,0% p/v evaluándoseles pH y conductividad eléctrica (S.cm -1 . Para la siembra se utilizaron bandejas cubiertas con una doble capa de papel absorbente sobre la que se colocó 20 semillas/bandeja, tapadas con dos hojas más de papel y regadas tres veces al día con los extrac- tos foliares. El tratamiento control recibió agua corriente. El diseño estadístico fue bloques al azar con cuatro concentraciones de extracto y cinco repeticiones. A los 12 días después de la siembra se determinaron los diferentes parámetros de germinación y crecimiento. Se práctico un análisis de varianza y regresión para los parámetros estudiados. El pH disminuyó y la CE incrementó al aumentar la concentración del extracto. La germinación, altura de las plántulas, longitud de las radículas, peso seco del vástago y relación peso seco del vástago/peso seco de la radícula dismi- nuyeron proporcionalmente al aumento de la concentración de extracto, contrariamente, el peso seco de la radícula incrementó. La relación altura de la plántula/longitud de la radícula no presentó diferencias signifi cativas en las fuentes de variación.

  7. EFFECT OF DIFFERENT MULCHES ON THE CONTROL OF UNWISHED PLANTS IN MAIZE CROP (Zea mays EFEITO DE DIVERSAS ESPÉCIES DE COBERTURA MORTA SOBRE O CONTROLE DE PLANTAS DANINHAS DA CULTURA DO MILHO

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    Rogério de Araújo Almeida

    2007-09-01

    ;">KEY-WORDS: Mulches; uwished plants; maize crop.

    Pesquisas em diversos países sul-americanos apontam o plantio direto para pequenos produtores como responsável por melhor conservação do solo e água, menores custos de produção e maiores rendimentos, melhorando o nível de vida dos produtores e propiciando sua permanência no meio rural. Os tratamentos normalmente incluem a aplicação de herbicidas e considera-se um desafio à pesquisa encontrar sistemas que viabilizem o plantio direto sem uso, ou com uso reduzido, de herbicidas. Objetivando avaliar os efeitos de diferentes coberturas mortas sobre o controle de plantas indesejáveis na cultura do milho (Zea mays, conduziu-se o presente trabalho, cujos tratamentos foram constituídos pelo cultivo de áreas de cem metros quadrados com as seguintes plantas: crotalária (Crotalaria juncea, milheto (Pennisetum americanum e girassol (Helianthus annus L., cultivares Stanzuela e V 2000. A semeadura foi efetuada na segunda quinzena do mês de abril e, decorridos sessenta dias, foi feito o plantio direto do milho, com matraca. Imediatamente após, as plantas constantes nas parcelas foram cortadas manualmente, constituindo-se em cobertura morta. Fez-se adubação de acordo com a análise do solo e a população adotada foi de 60.000 plantas por hectare. Não houve controle de plantas daninhas. Por ocasião do florescimento do milho, coletaram-se as plantas daninhas presentes nas parcelas, mediante amostragens de 1 m² (duas repetições. O material foi seco até peso constante. A análise estat

  8. INFLUENCIA DE TRES FECHAS DE SIEMBRA SOBRE EL CRECIMIENTO Y RENDIMIENTO DE ESPECIES DE CEREALES CULTIVADAS EN CONDICIONES TROPICALES. PARTE I. CULTIVO DEL MAÍZ (ZEA MAYS L.)

    OpenAIRE

    Naivy Hernández Córdova; Francisco Soto Carreño

    2012-01-01

    La productividad de un cultivo está determinada por su potencial genético y el impacto del ambiente sobre su capacidad de crecimiento y partición de materia seca hacia destinos reproductivos, por otro lado, cambios en la fecha de siembra del cultivo de maíz modifican la respuesta del rendimiento en grano. Por lo que el objetivo del presente trabajo fue estudiar el efecto de tres fechas de siembra sobre el comportamiento del crecimiento y su relación con el rendimiento en el cultivo del maí...

  9. ZEA MAIZE: A MODERN CRAZE

    OpenAIRE

    Dhamija Isha; Parle Milind

    2013-01-01

    Zea stands for ‘sustaining life’ and Mays stands for ‘life giver’. Zea mays is one of the oldest and most dynamic crop species, which has gained popularity in modern world too, due to its applications in diverse dishes. Corn is produced in every continent of the world with the exception of Antarctica. It is an annual monoecious sunny plant, surviving perfectly in nutrient rich, well-drained soil. Each and every part of the corn, from husk to corn silk is beneficial for the society. There are ...

  10. "Zea"-Because It's There

    Science.gov (United States)

    Chamberlain, Eric

    1983-03-01

    The Subject is a long standing symbiotic relationship between Zea and the movies. As usual the impossible was required - to attain cinema release quality films with dramatic interpretation - at the same time using Hy-speed macro photographic techniques. The subject was not to be recognizable until the end of the film - some four minutes long. Zea is explosive, it reacts to heat and is extremely difficult to predict when it will explode, which left little time for the focus, stop down and shooting. Using a Hy-cam at 5,000 pictures per second - a 400 ft. roll of 7247 raw stock, left but a brief three seconds for synchronization. To add to the confusion, two co-directors, a cameraman, plus equipment, were jammed into a 2 x 2m space. To achieve reasonable resolution for theatrical showing, 400,000 foot/candles of light were needed. This was achieved. The film was edited and music from Vaughan Williams' "Fantasia" recorded at St. Martins-in-the-Fields, London was added. The result was sent to the Cannes Film Festival, where it was given the Jury Award.

  11. ZEA MAIZE: A MODERN CRAZE

    Directory of Open Access Journals (Sweden)

    Dhamija Isha

    2013-06-01

    Full Text Available Zea stands for ‘sustaining life’ and Mays stands for ‘life giver’. Zea mays is one of the oldest and most dynamic crop species, which has gained popularity in modern world too, due to its applications in diverse dishes. Corn is produced in every continent of the world with the exception of Antarctica. It is an annual monoecious sunny plant, surviving perfectly in nutrient rich, well-drained soil. Each and every part of the corn, from husk to corn silk is beneficial for the society. There are more than 3,500 different uses for corn products. Corn does much more than feed people and livestock. The plant contains alkaloids, flavonoids, saponins, maizenic acid, vitamins B1, K and minerals like potassium, phosphorous and zinc. Traditionally, Maize is used as an analgesic, anti-diarrheal, anti-prostatitic, anti-lithiasis, anti-tumor, anti-hypertensive, anti-diabetic, anti-hyperlipidemic, anti-inflammatory and anti-oxidant. In this review article, we have narrated miscellaneous uses of corn varieties and described the pharmacological activities, phytoconstituents, nutritional value and traditional uses of maize. The maize has assorted uses like culinary, medicinal and industrial. Corn dishes like corn-meal, corn-flakes, popcorn, “makki ki roti” and corn soup highlight its dominance all over the world. Therefore, maize has become a craze among modern youth.

  12. Una filosofía para América Latina: Leopoldo Zea

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    Giuseppe Cacciatore

    2004-01-01

    Full Text Available Uno de los mas significativos recorrido filosoficos e hsitorico-culturales a traves de los que se ha manisfestado la reflexion sobre la identidad latinoamericana es indudablemente el trazado por el pensador mexicano Leopoldo Zea, alumno predilecto de jose gaos. En el, como en tanto otros intelectuales de los paises latinos del conteniente americano el problema de la individuacion de las trazas de una autonoma dimension filosofica (y de su ambivalente relacion con la tradicion indigena pre-colonial y con los modelos de la cultura europea se liga constante y significativamente al evento traumatico y dramatico de la conquista y del genocidio. Zea no se cierra en esta dicatomia civilizacion precolombina/civilizacion europea, ni olvida la que quizas es la verdadera especificidad del continente americano centromeridional, la multiculturalidad y la multietnia, el denominado mestizaje.

  13. Teosinte inflorescence phytolith assemblages mirror Zea taxonomy.

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    John P Hart

    Full Text Available Molecular DNA analyses of the New World grass (Poaceae genus Zea, comprising five species, has resolved taxonomic issues including the most likely teosinte progenitor (Zea mays ssp. parviglumis of maize (Zea mays ssp. mays. However, archaeologically, little is known about the use of teosinte by humans both prior to and after the domestication of maize. One potential line of evidence to explore these relationships is opaline phytoliths produced in teosinte fruit cases. Here we use multidimensional scaling and multiple discriminant analyses to determine if rondel phytolith assemblages from teosinte fruitcases reflect teosinte taxonomy. Our results indicate that rondel phytolith assemblages from the various taxa, including subspecies, can be statistically discriminated. This indicates that it will be possible to investigate the archaeological histories of teosinte use pending the recovery of appropriate samples.

  14. Urinary deoxynivalenol (DON) and zearalenone (ZEA) as biomarkers of DON and ZEA exposure of pigs.

    Science.gov (United States)

    Thanner, S; Czeglédi, L; Schwartz-Zimmermann, H E; Berthiller, F; Gutzwiller, A

    2016-05-01

    Four diets contaminated with 1.1 to 5.0 mg/kg deoxynivalenol (DON) and 0.4 to 2.4 mg/kg zearalenone (ZEA) were fed to four groups of six growing Large White pigs. Urine samples were collected after 3 to 4 days and again after 6 to 7 days on the diets. On each sampling day, half of the animals were sampled in the morning, after an 8-h fast, and the other half were sampled in the afternoon, after 7 h of ad libitum access to feed. The urinary concentrations of DON, DON-glucuronide, DON-3-sulphate, de-epoxy-DON, as well as of ZEA, ZEA-14-glucuronide, α-zearalenol and α-zearalenol-14-glucuronide, analysed using LC-MS/MS, were used to calculate urinary DON and ZEA equivalent concentrations (DONe and ZEAe). The urinary concentration of DONe (P intake per kg body weight the day preceding sampling (r = 0.76 and 0.77; P intake during the 7 h preceding urine sampling in the afternoon and urinary DONe/creatinine ratio (r = 0.88) as well as between mean ZEA intake during 3 days preceding urine sampling and urinary ZEAe/creatinine ratio (r = 0.84) were even higher, reflecting the plasma elimination half-time of several hours for DON and of more than 3 days for ZEA. ZEAe analysed in enzymatically hydrolysed urine using an ELISA kit was highly correlated with the LC-MS/MS data (r = 0.94). The urinary DONe and ZEAe to creatinine ratios, analysed in pooled urine samples of several pigs fed the same diet, can be used to estimate their exposure to DON and ZEA. PMID:26888520

  15. LOS FENOLES DEL POLEN DEL GÉNERO ZEA

    OpenAIRE

    Norma Almaraz-Abarca; Diana María Rivera-Rodríguez; David Arráez-Román; Antonio Segura-Carretero; José de Jesús Sánchez-González; Amanda Delgado-Alvarado; José Antonio Ávila-Reyes

    2013-01-01

    Se analizó la variabilidad de la composición fenólica del polen de 32 poblaciones de Zea mays subsp. mexicana, Zea mays subsp. parviglumis, Zea mays subsp. mays, Zea diploperennis, Zea perennis y Zea luxurians de México y Guatemala. Los perfiles se obtuvieron por cromatografía líquida de alta presión con detector de arreglo de diodos (HPLC-DAD) y cromatografía líquida de ultra resolución acoplada a espectrómetro de masas de tiempo de vuelo (UPLC-TOF-MS). Se encontró un total de 23 compuestos ...

  16. The Paleobiolinguistics of Maize (Zea mays L.

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    Cecil H. Brown

    2014-05-01

    Full Text Available Paleobiolinguistics is used to determine when and where maize (Zea mays developed significance for different prehistoric groups of Native America. Dates and locations of proto-languages for which maize terms reconstruct generally accord with crop-origin and dispersal information from plant genetics and archaeobotany. Paleobiolinguistic and other lines of evidence indicate that human interest in maize was extensive millennia before the widespread development of a village‐farming way of life in the New World.

  17. Urinary deoxynivalenol (DON) and zearalenone (ZEA) as biomarkers of DON and ZEA exposure of pigs.

    Science.gov (United States)

    Thanner, S; Czeglédi, L; Schwartz-Zimmermann, H E; Berthiller, F; Gutzwiller, A

    2016-05-01

    Four diets contaminated with 1.1 to 5.0 mg/kg deoxynivalenol (DON) and 0.4 to 2.4 mg/kg zearalenone (ZEA) were fed to four groups of six growing Large White pigs. Urine samples were collected after 3 to 4 days and again after 6 to 7 days on the diets. On each sampling day, half of the animals were sampled in the morning, after an 8-h fast, and the other half were sampled in the afternoon, after 7 h of ad libitum access to feed. The urinary concentrations of DON, DON-glucuronide, DON-3-sulphate, de-epoxy-DON, as well as of ZEA, ZEA-14-glucuronide, α-zearalenol and α-zearalenol-14-glucuronide, analysed using LC-MS/MS, were used to calculate urinary DON and ZEA equivalent concentrations (DONe and ZEAe). The urinary concentration of DONe (P < 0.001), but not of ZEAe (P = 0.31), was lower in the fasted than that in the fed animals. The urinary DONe/creatinine and ZEAe/creatinine ratios were highly correlated with DON and ZEA intake per kg body weight the day preceding sampling (r = 0.76 and 0.77; P < 0.001). The correlations between DON intake during the 7 h preceding urine sampling in the afternoon and urinary DONe/creatinine ratio (r = 0.88) as well as between mean ZEA intake during 3 days preceding urine sampling and urinary ZEAe/creatinine ratio (r = 0.84) were even higher, reflecting the plasma elimination half-time of several hours for DON and of more than 3 days for ZEA. ZEAe analysed in enzymatically hydrolysed urine using an ELISA kit was highly correlated with the LC-MS/MS data (r = 0.94). The urinary DONe and ZEAe to creatinine ratios, analysed in pooled urine samples of several pigs fed the same diet, can be used to estimate their exposure to DON and ZEA.

  18. Resistance in Zea mays to Heterodera zeae

    OpenAIRE

    Hashmi, Ghazala; Hashmi, Sarwar; Krusberg, Lorin R.; Huettel, Robin N.

    1993-01-01

    Twenty-three precommercial field corn lines (Zea mays) were screened in the greenhouse and in vitro for the ability to support reproduction of Heterodera zeae. Although H. zeae reproduced on all corn lines, reproduction was only 0.4 to 4.5% on the five least suitable corn lines in greenhouse tests compared with the susceptible check line Pioneer brand 3184. The least suitable experimental line supported an average of 30 cysts plus females after 8 weeks growth, whereas the susceptible check, P...

  19. Efecto del herbizida Antrazina sobre los microorganismos Diazótrofos asociados al cultivo de maíz ( Zea mays L. en un suelo de Saldaña (Tolima Effect of atrazine on the diaztrophos associated with corn cultivated on soil from Saldana, Tolima

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    Ordoñez Alba Ruth

    1999-11-01

    Full Text Available

    En un experimento de invernadero, se evaluó el efecto a través del tiempo de la aplicación del herbicida atrazina sobre la población de microorganisrnos diazótrofos asociados a raíz y suelo rizosférico de un cultivo de maíz en un suelo, Uscroper Fluvaquentic, franco-arcillo-arenoso de Saldaña (Tolima. El 61% de los aislamientos de suelo y el 83% de los de raíz presentaron crecimiento característico en forma de película blanquecina bajo la superficie del medio. La población de microorganismos diazótrofos de suelo rizosférico y la actividad de la nitrogenasa no presentaron diferencias significativas por la aplicación del herbicida. Los mayores valores en la actividad de la nitrogenasa se presentaron a los 45 días de aplicación del herbicida con la dosis más alta (3,0 Kg/ha. En las raíces de maíz, el testigo sin aplicación de atrazina presentó los valores más altos, sin embargo, tampoco en este caso se presentaron diferencias significativas entre las dosis ni a claves del tiempo. Se concluye que bajo las condiciones del experimento, hasta los 90 días, no se presentó efecto significativo de la aplicación de atrazina sobre la actividad ni sobre la población de diazotrofos presentes en la rizosfera y en la raíz de las plantas de maíz.

    The effect of the herbicide atrazine on the diazotrophic microorganisms associated with rhizosphere soil and roots of a corn cultivated on a clay-loam soil in a greenhouse, Ustropet Fluvaquentic from Saldana (Tolima was evaluated. 61% of soil isolates and 83% of root isolates presented characteristic cultural growth of whitish pellicle under the surface of the semisolid NFb-malic acid medium. The soil population of diazotrophic microorganisms and the nitrogenase activity were not significantly different between atrazine treatments. The highest values were obtained 45 days after the highest dose ofatrazine (3.0 Kg/ha. Corn roots without treatment had greater values

  20. Caracterización de los ácidos húmicos extraídos de cuatro lombricompuestos y su efecto sobre la germinación de semillas de maíz Zea mays L., algodón Gossypium hirsutum y tomate Lycopersicon esculentum L.

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    Gómez Zambrano Jairo

    1996-12-01

    Full Text Available

    The work perfomed to characterize the elemental composition and functional groups of humic acids extracted from four lombricompost cow dung, filter press cake of sugar cane, coffee pulp and grass residue the total content of essential elements and its distribution in the humic and no humic fractions were determined. It was evalued the effect of two concentrations of humic acids (150 and 300 ppm upon seed germination of maize, cotton and tomat. There were found differences in the elemental composition (CHON and functional groups (COOH, OH phedic and carbony of the humic acids atributed to variations in composition of the original substrates. The lombricompost of cow dung showed higher oxidation values (O/H = 0.49 than the lombricompost of filter press cake of sugar cane (0.40 sugering a higher grade of humification of the first. The grass residue showed higher contribution to the CIC (COOH + OH = 9. O me/g than the coffe pulp (7. 1 me/g the total essential elements were concentrated in the remanent residue, with lower content in the water and 0.1M HCL solutions; the fulvic and humic fractions had very low content of these elements. The humic acid at the concentrations tested did not have any effect on the germination of maize and cotton, and depressed the germination of tomato seeds.

    El trabajo se realizó con el fin de caracterizar por su composición elemental y contenido de grupos funcionales, los acidos húmicos extraídos de cuatro lombricompuestos (bovinaza, cachaza, pulpa de café y residuo de prado. Se determinó el contenido y distribución de los elementos esenciales totales en las fracciones húmicas y no de acidos húmicas. Se evaluó el efecto de dos concentraciones de acidos húmicos (150 y 300 ppm sobre la germinación de semillas de maíz, algodón y tomate. Se encontraron diferencias en el contenido elemental (CHON y grupos funcionales (COOH, OH fenólico y carbonilo atribuido a variaciones en la composición de los

  1. Mixed Reality Cultural Heritage Communication - The Zea Case

    DEFF Research Database (Denmark)

    Veirum, Niels Einar; Christensen, Mogens Fiil; Mayerhofer, Mikkel

    use of experience products like computer-games, IMAX cinemas and theme parks featuring virtual reality installations. “It’s a question of stone-axe displays versus Disney-power installations” as one of the involved museum professionals point it, “but we don’t want any of these possibilities...... Case is a design scenario for the Museum of the Future showing how Cultural Heritage institutions can use a Glocal Approach to technology and architecture to reinvent the relation to the visitor and the neighbourhood. While Mixed Reality can be used for Cultural Heritage Communication in traditional......”. The poster presents an actual experience design case in Zea Harbour, Greece dealing with these challenges using mixed reality communicating cultural heritage material. Archaeological findings, physical reconstructions and digital models are mixed to effectively stage the interactive experience space. The Zea...

  2. Long distance migration in Helicoverpa zea: What we know and need to know

    Science.gov (United States)

    This paper identifies knowledge and knowledge gaps in the areas of biology and ecology, and migratory flight of corn earworm, Helicoverpa zea (Boddie). The paper focuses on results from studies of H. zea population dynamics and migration in Texas during a period of substantial irrigated corn produc...

  3. PATOGENICIDAD BACTERIANA EN MAÍZ (ZEA MAYS)

    OpenAIRE

    Rocío Pérez-y-Terrón; Julio César Carmona Díaz; Jorge Alejandro Cebada Ruíz; José Antonio Munive Hernández

    2012-01-01

    El maíz es un grano de consumo mundial para alimento tanto humano como animal. México se encuentra en el séptimo lugar de la producción, China y Estados Unidos son los principales consumidores. Zea mays pertenece a la familia de las gramíneas y tiene producción anual. La planta se puede ver afectada por plagas principalmente de diferentes especies de insectos. Puede también desarrollar enfermedad debida a hongos y virus, así como a bacterias patogénicas. Dentro de estas la causada por organis...

  4. Extração de corantes de milho (Zea mays L.) Extraction of corn colorants (Zea mays L.)

    OpenAIRE

    Felix Martin Cabajal Gamarra; Gisele Costa Leme; Elias Basile Tambourgi; Edison Bittencourt

    2009-01-01

    Os corantes naturais foram amplamente utilizados de forma artesanal até antes do surgimento dos corantes sintéticos. O estudo e uso dos corantes naturais voltaram a ter importância nestes últimos anos devido aos questionamentos dos organismos internacionais da saúde e dos consumidores pelo uso indiscriminado dos corantes sintéticos, ligados ao desenvolvimento de doenças degenerativas e ao impacto ambiental. O corante extraído do milho roxo (Zea mays L.) tem sido utilizado ao longo da história...

  5. EVALUACIÓN MORFOAGRONÓMICA DE UNA POBLACIÓN DE MAÍZ (Zea mays, L.) EN CONDICIONES DE POLINIZACIÓN ABIERTA EN EL MUNICIPIO BATABANÓ, PROVINCIA MAYABEQUE

    OpenAIRE

    Rosa Acosta Roca; Adán R. Colomer López; Humberto Ríos Labrada; Michel Martínez Cruz

    2013-01-01

    La variabilidad genética del maíz (Zea mays, L.) es debida a los mismos mecanismos que operan en las poblaciones de los organismos en el proceso evolutivo, tanto en aquellas naturales como en las que están sometidas a domesticación; así como a los numerosos nichos ecológicos y los efectos ambientales que cada condición climática ejerce sobre las poblaciones en su adaptación. Sin embargo, han sido poco documentadas las experiencias de los programas de mejora genética desarrollado por productor...

  6. PATOGENICIDAD BACTERIANA EN MAÍZ (ZEA MAYS

    Directory of Open Access Journals (Sweden)

    Rocío Pérez-y-Terrón

    2012-01-01

    Full Text Available El maíz es un grano de consumo mundial para alimento tanto humano como animal. México se encuentra en el séptimo lugar de la producción, China y Estados Unidos son los principales consumidores. Zea mays pertenece a la familia de las gramíneas y tiene producción anual. La planta se puede ver afectada por plagas principalmente de diferentes especies de insectos. Puede también desarrollar enfermedad debida a hongos y virus, así como a bacterias patogénicas. Dentro de estas la causada por organismos del género Pantoea. P. stewartii se sabe que tiene genes como cps que codifican para la producción de exopolisacarido sterwatan controlada por un mecanismo de quórum sensing, y hrp para el sistema de secreción tipo III involucrados en la patogenicidad de la bacteria.

  7. Mutational effects of space flight on Zea mays seeds

    Science.gov (United States)

    Mei, M.; Qiu, Y.; He, Y.; Bucker, H.; Yang, C. H.

    1994-01-01

    The growth and development of more than 500 Zea mays seeds flown on Long Duration Exposure Facility (LDEF) were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the dose to which maize seeds might be exposed during the flight was estimated to be equivalent to 635 cGy of gamma rays. Seeds from one particular holder gave a high mutation frequency and a wide mutation spectrum. White-yellow stripes on leaves were also found in some of the inbred progenies from plants displayed somatic mutation. Electron microscopy studies showed that the damage of chloroplast development in the white-yellow stripe on leaves was similar between seeds flown on LDEF and that irradiated by accelerated heavy ions on ground.

  8. Digital signage sobre IP

    OpenAIRE

    Casademont Filella, Albert

    2012-01-01

    Projecte que versa sobre el disseny i la implementació d'un sistema de Digital Signage (Cartelleria Digital) sobre IP, creant un gestor que permeti controlar de forma remota tot un conjunt de petits dispositius connectats a pantalles que emeten continguts multimèdia com vídeos, imatges, feeds rss...

  9. Ultrafiltros sobre ω.

    OpenAIRE

    Mancilla Hernández, Salvador

    2012-01-01

    El objetivo del presente trabajo estudiar los ideales y filtros sobre conjuntos numerables, los que comúnmente conocemos como filtros sobre ω o ideales sobre ω. Dentro de estos, nos enfocaremos en la clase de I-ultrafiltros los cuales fueron estudiados por James Baumgartner en [11]. Y dentro de esta clase de ultrafiltros, nos concentraremos cuando I es {A ⊆ ω : n∈A g(n) < ∞}, también conocido como ideal sumable con respecto a g, donde g es una sucesión de números reales no negativ...

  10. Integration of inherited sterility and other pest management strategies for Helicoverpa zea: Status and potential

    International Nuclear Information System (INIS)

    The corn earworm, Helicoverpa zea (Boddie), is one of the most destructive pests of field crops in the United States of America. Currently, control of H. zea is achieved almost entirely through the use of synthetic insecticides. However, successful application of the inherited sterility principle to a wild population of H. zea during a pilot test has encouraged further development of this pest control strategy. Data from recent studies and population models suggest that the full potential of inherited sterility as an area wide control strategy for H. zea and other lepidopteran pests may be realized only when inherited sterility is integrated with other suppression methods. Applications of singular, non-insecticidal methods for area wide suppression of H. zea have had limited success and have been vulnerable to temporary programme failures (e.g. inclement weather, reduced insect rearing output, etc.). An integrated approach would be horizontally diversified through the use of several strategies which use different modes of action and, therefore, would be less vulnerable to temporary programme failures than would a single strategy. Combining two or more control strategies with additive effects may increase programme efficiency. However, the greatest benefit in combining inherited sterility with other control strategies is the dynamic synergistic effects. The demonstrated potential of inherited sterility to reduce the reproductive ability of H. zea and the demonstrated capacity of inherited sterility to perform compatibly and synergistically with other control strategies suggest that inherited sterility should be major component of future integrated approaches to managing H. zea. (author). 13 refs, 2 figs

  11. Extração de corantes de milho (Zea mays L. Extraction of corn colorants (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Felix Martin Cabajal Gamarra

    2009-03-01

    Full Text Available Os corantes naturais foram amplamente utilizados de forma artesanal até antes do surgimento dos corantes sintéticos. O estudo e uso dos corantes naturais voltaram a ter importância nestes últimos anos devido aos questionamentos dos organismos internacionais da saúde e dos consumidores pelo uso indiscriminado dos corantes sintéticos, ligados ao desenvolvimento de doenças degenerativas e ao impacto ambiental. O corante extraído do milho roxo (Zea mays L. tem sido utilizado ao longo da história pela civilização Inca na preparação de alimentos e no tingimento de fibras têxteis. Neste trabalho, os pigmentos do grupo das antocianinas foram extraídos das variedades de milho roxo e do milho vermelho (Z. mays L. e depois foram caracterizados. Três métodos de extração foram utilizados: imersão, lixiviação com algumas modificações e extração supercrítica (ESC. O melhor método para extração foi o da lixiviação que alcançou 88% (m/m de rendimento, em função da massa do corante extraído e da matéria-prima. Também utilizando a lixiviação modificada, foi possível concentrar em 3% os compostos acilados, assim como recuperar 85% dos solventes utilizados. Um indicador de pH foi obtido pela fixação das antocianinas num papel de filtro, com base na estabilidade das antocianinas, ferramenta que pode ser utilizada em laboratórios de ensino de química.Natural colorants were craftly made and widely used before the discovery of the synthetic colorants. The study and the use of natural colorants have become important again in the last few years due to questions raised by the international health organizations and consumers related to the indiscriminate use of synthetic colorants which were linked to the development of degenerative illnesses and environmental impact. The colorant extracted from purple corn (Zea Mays L. was used by the Inca civilization to prepare food and to dye textile fibers. In this work, pigments from the

  12. Kinetics of 15NH4+ assimilation in Zea mays

    International Nuclear Information System (INIS)

    Comparative studies of 15NH4+ assimilation were undertaken with a GDH1-null mutant of Zea mays and a related (but not strictly isogenic) GDH1-positive wild type from which this mutant was derived. The kinetics of 15NH4+ assimilation into free amino acids and total reduced nitrogen were monitored in both roots and shoots of 2-week-old seedlings supplied with 5 millimolar 99% (15NH4)2SO4 via the aerated root medium in hydroponic culture over a 24-h period. The GDH1-null mutant, with a 10- to 15-fold lower total root GDH activity in comparison to the wild type, was found to exhibit a 40 to 50% lower rate of 15NH4+ assimilation into total reduced nitrogen. The lower rates of 15NH4+ assimilation in the mutant was associated with lower rates of labeling of several free amino acids (including glutamate, glutamine-amino N, aspartate, asparagine-amino N, and alanine) in both roots and shoots of the mutant in comparison to the wild type. Qualitatively, these labeling kinetics appear consistent with a reduced flux of 15N via glutamate in the GDH1-null mutant. However, the responses of the two genotypes to the potent inhibitor of glutamine synthetase, methionine sulfoximine, and differences in morphology of the two genotypes (particularly a lower shoot:root ratio in the GDH1-null mutant) urge caution in concluding that GDH1 is solely responsible for these differences in ammonia assimilation rate

  13. Nascent transcription affected by RNA polymerase IV in Zea mays.

    Science.gov (United States)

    Erhard, Karl F; Talbot, Joy-El R B; Deans, Natalie C; McClish, Allison E; Hollick, Jay B

    2015-04-01

    All eukaryotes use three DNA-dependent RNA polymerases (RNAPs) to create cellular RNAs from DNA templates. Plants have additional RNAPs related to Pol II, but their evolutionary role(s) remain largely unknown. Zea mays (maize) RNA polymerase D1 (RPD1), the largest subunit of RNA polymerase IV (Pol IV), is required for normal plant development, paramutation, transcriptional repression of certain transposable elements (TEs), and transcriptional regulation of specific alleles. Here, we define the nascent transcriptomes of rpd1 mutant and wild-type (WT) seedlings using global run-on sequencing (GRO-seq) to identify the broader targets of RPD1-based regulation. Comparisons of WT and rpd1 mutant GRO-seq profiles indicate that Pol IV globally affects transcription at both transcriptional start sites and immediately downstream of polyadenylation addition sites. We found no evidence of divergent transcription from gene promoters as seen in mammalian GRO-seq profiles. Statistical comparisons identify genes and TEs whose transcription is affected by RPD1. Most examples of significant increases in genic antisense transcription appear to be initiated by 3'-proximal long terminal repeat retrotransposons. These results indicate that maize Pol IV specifies Pol II-based transcriptional regulation for specific regions of the maize genome including genes having developmental significance. PMID:25653306

  14. Pemodelan Pertumbuhan Zea Mays L. Menggunakan Sthochastic L-System

    Directory of Open Access Journals (Sweden)

    Juhari Juhari

    2013-11-01

    Full Text Available L-Systems memiliki fleksibilitas dalam mensimulasikan struktur dan proses pengembangan pertumbuhan tanaman secara visual dan realistik. Penelitian ini bertujuan untuk memodelkan pertumbuhan tanaman jagung menggunakan L-Systems dan memvisualisasikan model pertumbuhan tanaman jagung tersebut dari kecil hingga dewasa dalam ruang dimensi tiga. Penelitian dilakukan dalam tiga tahap yang diawali dari identifikasi kebutuhan data tehadap pertumbuhan tanaman jagung (Zea Mays L.. Tahap kedua, membangun model secara manual yang meliputi identifikasi dan penentuan komponen L-Systems (huruf, aksioma, dan aturan produksi. Tahap ketiga, melakukan simulasi dan visualisasi model pertumbuhan tanaman jagung yang telah didapat menggunakan processing dengan bahasa java dalam ruang dimensi tiga. Ketiga tahapan tersebut menghasilkan model Stochastic L-Systems dari pertumbuhan tanaman jagung dalam ruang dimensi tiga. Visualisasi model tanaman jagung yang telah dihasilkan pada penelitian ini lebih menekankan pada penyempurnaan model yang dilakukan pada penelitian sebelumnya terutama pada pewarnaan, pembentukan batang, dan adanya tulang daun pada tanaman jagung setiap iterasinya. Model tanaman jagung divisualisasikan mulai dari kecil hingga dewasa (fase vegetatif yang memiliki tulang daun dan kelengkungan daun berbeda dari daun bawah sampai pada daun atas. Tanaman jagung yang divisualisasikan hanya terbatas sampai 8 iterasi saja yang sudah mampu mewakili pertumbuhan tanaman jagung pada fase vegetatif

  15. Acclimation improves salt stress tolerance in Zea mays plants.

    Science.gov (United States)

    Pandolfi, Camilla; Azzarello, Elisa; Mancuso, Stefano; Shabala, Sergey

    2016-08-20

    Plants exposure to low level salinity activates an array of processes leading to an improvement of plant stress tolerance. Although the beneficial effect of acclimation was demonstrated in many herbaceous species, underlying mechanisms behind this phenomenon remain poorly understood. In the present study we have addressed this issue by investigating ionic mechanisms underlying the process of plant acclimation to salinity stress in Zea mays. Effect of acclimation were examined in two parallel sets of experiments: a growth experiment for agronomic assessments, sap analysis, stomatal conductance, chlorophyll content, and confocal laser scanning imaging; and a lab experiment for in vivo ion flux measurements from root tissues. Being exposed to salinity, acclimated plants (1) retain more K(+) but accumulate less Na(+) in roots; (2) have better vacuolar Na(+) sequestration ability in leaves and thus are capable of accumulating larger amounts of Na(+) in the shoot without having any detrimental effect on leaf photochemistry; and (3) rely more on Na(+) for osmotic adjustment in the shoot. At the same time, acclimation affect was not related in increased root Na(+) exclusion ability. It appears that even in a such salt-sensitive species as maize, Na(+) exclusion from uptake is of a much less importance compared with the efficient vacuolar Na(+) sequestration in the shoot. PMID:27372277

  16. FITOMEJORAMIENTO PARTICIPATIVO DEL MAÍZ ( Zea mays L.. UNA EXPERIENCIA EN LA HABANA

    Directory of Open Access Journals (Sweden)

    Lianne Fernández

    2003-01-01

    Full Text Available Los objetivos del trabajo fueron conocer los materiales seleccionados por los agricultores y los criterios de selección según el sexo y la localidad, así como describir y evaluar los materiales de maíz utilizados desde el punto de vista morfológico y agronómico. El trabajo se realizó en la Coo- perativa de Producción Agropecuaria “Gilberto León”, San Antonio de los Baños, provincia Habana. Se sembraron 97 entradas de maíz ( Zea mays L., 40 procedentes de la colección de germoplasma del Instituto de Investigaciones Fundamen- tales en Agricultura Tropical (INIFAT, 56 del Instituto Nacio- nal de Ciencias Agrícolas (INCA y un material seleccionado por un campesino de la CPA «Gilberto León». A los 100 días de la siembra se efectuó una feria con agricultores de dos locali- dades: San Antonio de los Baños y Batabanó, donde hubo representación de mujeres y hombres. A estos agricultores se les hizo una encuesta en el campo durante la feria que recogía sus criterios en el momento de seleccionar sus materiales. A estos resultados se les realizó un estudio de frecuencia, con el fin de a grupar la información y también se evaluaron algunos caracteres relacionados con el rendimiento. Los resultados re- velan el conocimiento y la experiencia sobre el cultivo del maíz, teniendo en cuenta la localidad y el sexo de los agricultores. Los caracteres utilizados fueron adecuados para caracterizar y describir los materiales. El análisis de los componentes principales permitió una adecuada clasificación de los materiales en cuatro grupos, para los componentes 1 y 2, con una con- tribución de la variación en los tres primeros componentes de un 67.39 %.

  17. Retroelement genome painting: cytological visualization of retroelement expansions in the genera Zea and Tripsacum.

    Science.gov (United States)

    Lamb, Jonathan C; Birchler, James A

    2006-06-01

    Divergence of abundant genomic elements among the Zea and Tripsacum genera was examined cytologically and a tool kit established for subsequent studies. The LTR regions from the CRM, Huck, Grande, Prem1, Prem2/Ji, Opie, Cinful-1, and Tekay retroelement families were used as FISH probes on mitotic chromosome spreads from a "trispecies" hybrid containing chromosomes from each of three species: Zea mays (2n = 20), Z. diploperennis (2n = 20), and Tripsacum dactyloides (2n = 36). Except for Tekay, which painted both Zea and Tripsacum chromosomes with nearly equal intensity, the retroelement probes hybridized strongly to the Zea chromosomes, allowing them to be distinguished from those of Tripsacum. Huck and Grande hybridized more intensely to maize than to Z. diploperennis chromosomes. Tripsacum genomic clones containing retroelement sequences were isolated that specifically paint Tripsacum chromosomes. The retroelement paints proved effective for distinguishing different genomes in interspecific hybrids and visualizing alien chromatin from T. dactyloides introgressed into maize lines. Other FISH probes (180-bp knob, TR-1, 5S, NOR, Cent4, CentC, rp1, rp3, and alpha-ZeinA) could be simultaneously visualized with the retroelement probes, emphasizing the value of the retroelement probes for cytogenetic studies of Zea and Tripsacum. PMID:16582446

  18. Biology, Ecology, and Evolving Management of Helicoverpa zea (Lepidoptera: Noctuidae) in Sweet Corn in the United States.

    Science.gov (United States)

    Olmstead, Daniel L; Nault, Brian A; Shelton, Anthony M

    2016-08-01

    The corn earworm, Helicoverpa zea (Boddie), is a polyphagous pest found throughout the United States, where it attacks many field and vegetable crops. Although H. zea has long been a traditional pest of sweet corn, its importance to this crop has increased dramatically over the past two decades. In this review, we summarize information critical for current and future management of H. zea in sweet corn production in the United States. First, we discuss the pest status of H. zea and its life history, including migration, infestation and larval development, diapause, overwintering, and abiotic factors that affect its biology. Next we describe monitoring methods, crop protection decision-making processes, chemical control options, and the use of genetic technologies for control of H. zea Alternative H. zea management options including biological control, cultural controls, host plant resistance, and pheromone disruption are also reviewed. The role of climate change and its effects on H. zea and its ecology are discussed, as well as the recent invasion of its relative, Helicoverpa armigera (Hübner), which is a major pest of corn in other parts of the world. To conclude, we suggest future research opportunities for H. zea and H. armigera management in sweet corn. PMID:27329622

  19. Graviresponsiveness of surgically altered primary roots of Zea mays

    Science.gov (United States)

    Maimon, E.; Moore, R.

    1991-01-01

    We examined the gravitropic responses of surgically altered primary roots of Zea mays to determine the route by which gravitropic inhibitors move from the root tip to the elongating zone. Horizontally oriented roots, from which a 1-mm-wide girdle of epidermis plus 2-10 layers of cortex were removed from the apex of the elongating zone, curve downward. However, curvature occurred only apical to the girdle. Filling the girdle with mucilage-like material transmits curvature beyond the girdle. Vertically oriented roots with a half-girdle' (i.e. the epidermis and 2-10 layers of the cortex removed from half of the circumference of the apex of the elongating zone) curve away from the girdle. Inserting the half-girdle at the base of the elongating zone induces curvature towards the girdle. Filling the half-circumference girdles with mucilage-like material reduced curvature significantly. Stripping the epidermis and outer 2-5 layers of cortex from the terminal 1.5 cm of one side of a primary root induces curvature towards the cut, irrespective of the root's orientation to gravity. This effect is not due to desiccation since treated roots submerged in water also curved towards their cut surface. Coating a root's cut surface with a mucilage-like substance minimizes curvature. These results suggest that the outer cell-layers of the root, especially the epidermis, play an important role in root gravicurvature, and the gravitropic signals emanating from the root tip can move apoplastically through mucilage.

  20. Todo sobre el neobarroco

    Directory of Open Access Journals (Sweden)

    Arturo Carrera

    2007-07-01

    Full Text Available Lo que hemos escuchado y atendido hasta aquí, hoy, ayer, sobre todo en la propuesta poética esbozada por Sergio Raimondi en su ensayo sobre Aldo Oliva, demuestra que las singularidades, su pasión, anulan subrepticiamente las nominaciones.Anoche en la televisión una orquesta sinfónica y un coro numeroso. Súbitamente, me hubiera gustado ser uno de esos intérpretes solitarios para sí, a pesar de la armonía, anónimos, a pesar del brillo sonoro… un violín, un triángulo… apenas… tres grillos… como ...

  1. Inferencias sobre Grafos

    OpenAIRE

    Sira M. Allende; Carlos N. Bouza

    2002-01-01

    El estudio de un juego puede ser modelado asumiendo que solo algunas partidas son observadas. Entonces el árbol del juego debe ser estimado utilizando información muestral. Similarmente ocurre al obtener información sobre el comportamiento de las decisiones tomadas por individuos muestreados sobre un árbol de decisión teórico. Al considerar una medida de probabilidad que caracterice el comportamiento de redes aleatorias se puede obtener un estimado del árbol asociado. Este problema es el anal...

  2. Mitos sobre agroecologia.

    OpenAIRE

    Canuto, João Carlos

    2011-01-01

    O presente ensaio vem a discutir alguns aspectos do discurso sobre a Agroecologia, procurando evidenciar contradições do senso comum, advindas seja de parte da comunidade leiga, dos meios de comunicação ou da comunidade científica. Coloca em debate alguns mitos sobre os sistemas agroecológicos, tais como: que sejam tecnologicamente retrógrados, de baixa produtividade, exigentes em mão-de-obra, economicamente inviáveis e “puramente ideológicos”.

  3. The effect of lead on the photoelectric reaction of Zea mays L. plants.

    Science.gov (United States)

    Pazurkiewicz-Kocot, K; Pietruszka, M

    2000-09-01

    We investigate the correlation between the concentrations of lead (10(-6)-10(-2) mol dm(-3) PbCl2) in the external medium and photoelectric reaction of Zea mays L. plants. The experiments were carried out on 8-10-day-old maize plants (Zea mays L. var. K33 x F2) with the use of conventional electrophysiological technique. The results suggest that in plants treated with lead ions the photoelectric reaction is significantly reduced. The pH variation of the incubation medium including the green fragments of leaves showed that lead ions caused inhibition of light-induced external acidification.

  4. Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays

    Science.gov (United States)

    Lewer, P.; Bandurski, R. S.

    1987-01-01

    7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

  5. Production and characterization of amylases from Zea mays malt

    Directory of Open Access Journals (Sweden)

    Joana Paula Menezes Biazus

    2009-08-01

    Full Text Available In this work the α and β-amylase enzymes were obtained from maize (Zea mays malt and were biochemistry characterized. A germination study to obtain the maize malt with good amylase activity was made. The maize seeds were germinated in laboratory and the enzymatic activity was measured daily. Activity dependence to germination time were fitted to an exponential model (A=A0eµt, which showed that the behaviour of enzymatic activity in the germination process was similar to the growth of the microorganism. Its model could be applied to describe the mechanism of α-amylase production for each maize varieties and others cereals. Maize malt characterization showed that α and β-amylase had optimal pH between 4-6.5, optimal temperature 50 and 90ºC, and molecular weight of 67.4 and 47.5kDa, respectively. This work contributed with the advances in biotechnology generating of conditions for application of a new and of low price amylases source.Neste trabalho as enzimas α e β-amilases foram obtidas de malte de milho e depois foram caracterizadas bioquimicamente. Um estudo da germinação foi feito para obtenção do malte com boa atividade amilásica. A germinação ocorreu em escala laboratorial e a atividade enzimática foi medida diariamente. Um modelo exponencial do tipo A=A0eµt foi ajustado a dependência do tempo de germinação com a atividade, mostrando que o comportamento da atividade enzimática no processo de germinação é semelhante ao crescimento de microorganismos. Este modelo pode ser aplicado para descrever o mecanismo de produção da α-amilase para cada variedade de milho e de outros cereais. A caracterização do malte de milho mostrou que as α e β-amilase têm pH ótimo entre 4,0-6,5, temperatura ótima de 50 e 90ºC, e massa molar de 67,4 e 47,5 kDa, respectivamente. Este trabalho contribuiu com os avanços da biotecnologia gerando condições de emprego de uma nova e barata fonte de amilases.

  6. A maize (Zea mays) line resistant to herbivory constitutively releases (E)-B-caryophyllene

    Science.gov (United States)

    Maize (Zea mays L.) is an important agricultural crop. Various insect pests such as those in the order of Lepidoptera frequently feed on young maize plants and pose a significant threat to plant development and survival. To deal with this problem, maize generates a wide variety of responses to att...

  7. A new gland associated with the retrocerebral complex of the adult corn earworm, Helicoverpa zea

    Science.gov (United States)

    We report the discovery of a putative new gland associated with the retrocerebral complex in the adults of Helicoverpa zea. The gland was not observed in Manduca sexta and few other species of moths. The pair of glands, each 40-60 µm in diameter, is located on either side of the recurrent nerve. Eac...

  8. Cytodifferentiation during callus initiation and somatic embryogenesis in Zea mays L.

    NARCIS (Netherlands)

    Fransz, P.F.

    1988-01-01

    This thesis deals with cytomorphogenic aspects during various phases of regeneration in tissue cultures of Zeamays L. Regeneration through tissue culture has been shown in an increasing number of plant species and is applied on large scale in agriculture and horticulture. Nevertheless,

  9. Differential distribution of cadmium in lettuce (Lactuca sativa L.) and maize (Zea mays L.).

    NARCIS (Netherlands)

    Florijn, P.J.

    1993-01-01

    Large genotypic variation in shoot Cd concentrations has been reported in literature for several plant species including lettuce ( Lactuca sativa L.) and maize ( Zea mays L.). The objective of this thesis was to elucidate the physiological andlor morphological basis of this differential behaviour us

  10. The economic evaluation of cocoyam (Xanthosoma sp) and Maize (Zea mays) in a mixed cropping system

    NARCIS (Netherlands)

    Sagoe, R.; Haleegoah, J.; Marfo, K.A.

    2006-01-01

    Cocoyam (Xanthosoma sp.) and maize (Zea mays) are major food crops often grown in association. On-farm testing at Sunyani, Sankore and Begoro in the forest ecology of Ghana evaluated the agronomic performance and economic productivity of both crops grown as mixed crops and sole crop. The cropping sy

  11. Cloning and sequencing of the casein kinase 2 alpha subunit from Zea mays

    DEFF Research Database (Denmark)

    Dobrowolska, G; Boldyreff, B; Issinger, O G

    1991-01-01

    The nucleotide sequence of the cDNA coding for the alpha subunit of casein kinase 2 of Zea mays has been determined. The cDNA clone contains an open reading frame of 996 nucleotides encoding a polypeptide comprising 332 amino acids. The primary amino acid sequence exhibits 75% identity to the alpha...

  12. Characterization of phenylpropanoid pathway genes within European maize (Zea mays L.) inbreds

    DEFF Research Database (Denmark)

    Andersen, Jeppe Reitan; Zein, Imad; Wenzel, Gerhard;

    2008-01-01

    genomic fragments of six putative phenylpropanoid pathway genes in a panel of elite European inbred lines of maize (Zea mays L.) contrasting in forage quality traits. Six loci, encoding C4H, 4CL1, 4CL2, C3H, F5H, and CAD, displayed different levels of nucleotide diversity and linkage disequilibrium (LD...

  13. Chromosomal Location by Use of Trisomics and New Alleles of an Endopeptidase in Zea Mays

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Scandalios, John G.

    1974-01-01

    An association was found earlier between the Ep1 gene locus coding for an endopeptidase and the endosperm color gene Y1 on chromosome 6 of Zea mays. By employing primary trisomics we have unequivocally placed the Ep1 gene on chromosome 6, closely linked to the Y1 locus. Additionally we describe new...

  14. Potassium fertilization mitigates the adverse effects of drought on selected Zea mays cultivars

    Science.gov (United States)

    In the present study, the role of potassium (K) in mitigating the adverse effects of drought stress (DS) on 2 maize (Zea mays L.) cultivars, ‘Shaandan 9’ (S9; drought-tolerant) and ‘Shaandan 911’ (S911; drought-sensitive), was assessed. K application increased dry matter (DM) across all growth stage...

  15. Inferencias sobre Grafos

    Directory of Open Access Journals (Sweden)

    Sira M. Allende

    2002-05-01

    Full Text Available El estudio de un juego puede ser modelado asumiendo que solo algunas partidas son observadas. Entonces el árbol del juego debe ser estimado utilizando información muestral. Similarmente ocurre al obtener información sobre el comportamiento de las decisiones tomadas por individuos muestreados sobre un árbol de decisión teórico. Al considerar una medida de probabilidad que caracterice el comportamiento de redes aleatorias se puede obtener un estimado del árbol asociado. Este problema es el analizado en este trabajo. Algunos resultados experimentales obtenidos usando Recocido Simulado ilustran el procedimiento. Su papel en el estudio de modelos económicos y de mercadeo es discutido.

  16. Estudios sobre Borges

    OpenAIRE

    Facultad de Humanidades y Ciencias de la Educación

    1991-01-01

    Contenidos de la obra: De Barthes a Pierre Menard | José Luis De Diego Pierre Menard, autor del Quijote: De la poligrafía al fraude | Andrea Cucatto Homenaje a Roberto Arlt: La otra cara de la moneda | Fabio Espósito Emma a través del espejo: Una lectura de Emma Zunz | Graciela Beatriz Goldchluk Sobre el concepto de verdad en Borges | Sergio Pastormerlo

  17. Revisiting macronutrient regulation in the polyphagous herbivore Helicoverpa zea (Lepidoptera: Noctuidae): New insights via nutritional geometry.

    Science.gov (United States)

    Deans, Carrie A; Sword, Gregory A; Behmer, Spencer T

    2015-10-01

    Insect herbivores that ingest protein and carbohydrates in physiologically-optimal proportions and concentrations show superior performance and fitness. The first-ever study of protein-carbohydrate regulation in an insect herbivore was performed using the polyphagous agricultural pest Helicoverpa zea. In that study, experimental final instar caterpillars were presented two diets - one containing protein but no carbohydrates, the other containing carbohydrates but no protein - and allowed to self-select their protein-carbohydrate intake. The results showed that H. zea selected a diet with a protein-to-carbohydrate (p:c) ratio of 4:1. At about this same time, the geometric framework (GF) for the study of nutrition was introduced. The GF is now established as the most rigorous means to study nutrient regulation (in any animal). It has been used to study protein-carbohydrate regulation in several lepidopteran species, which exhibit a range of self-selected p:c ratios between 0.8 and 1.5. Given the economic importance of H. zea, and it is extremely protein-biased p:c ratio of 4:1 relative to those reported for other lepidopterans, we decided to revisit its protein-carbohydrate regulation. Our results, using the experimental approach of the GF, show that H. zea larvae self-select a p:c ratio of 1.6:1. This p:c ratio strongly matches that of its close relative, Heliothis virescens, and is more consistent with self-selected p:c ratios reported for other lepidopterans. Having accurate protein and carbohydrate regulation information for an insect herbivore pest such as H. zea is valuable for two reasons. First, it can be used to better understand feeding patterns in the field, which might lead to enhanced management. Second, it will allow researchers to develop rearing diets that more accurately reflect larval nutritional needs, which has important implications for resistance bioassays and other measures of physiological stress. PMID:26141409

  18. FERTILIZER APPLICATION METHODS AND IRRIGATION LEVELS ON EARLY (Zea mays L. DEVELOPMENT FORMAS DE APLICAÇÃO DO FERTILIZANTE E NÍVEIS DE IRRIGAÇÃO NO DESENVOLVIMENTO DO MILHO (Zea mays

    Directory of Open Access Journals (Sweden)

    Jorge Luiz do Nascimento

    2007-09-01

    Full Text Available

    Early corn development (Zea mays L. was evaluated through roots (MR and tops (MA dry matter in a low tunnel greenhouse pot experiment, in a 2x2x4 factorial completely randomized design with three replications, comparing the following treatments: two Oxisols (a sandy Latossolo Vermelho Escuro — LE and a clay Latossolo Roxo - LR; two methods of fertilizer application (soil mixed - A1, and furrow planting line - A2, and four irrigation levels (0%, 15%, 30%, and 45% deficit in relation to the evapotranspired water. Significant effects were observed for fertilizer application methods and irrigation levels on MA, with 89,6% higher yield for A2, and MA reduction for increased water stress. There was a significant interaction between soil types and fertilizer application methods on MA, with a larger MA in the LE soil for A1 method, while MA was larger in the LR soil for A2 method. For MR, it was observed a significant effect of soil type and fertilizer application methods, with a larger yield in the LR soil under the A2 form. The findings confirm the importance of adequate soil water supply for nutrient absorption processes, resulting in better plant development. The localized fertilizer application is recommended for Oxisols with higher clay contents and larger phosphorus fixation capacity.

    KEY-WORDS: Fertilizer; irrigation levels; Zea mays.

    O desenvolvimento inicial da cultura do milho (Zea mays L. foi avaliado através da

  19. Informe APEI sobre movilidad

    OpenAIRE

    Arroyo Vázquez, Natalia

    2011-01-01

    Este informe incluye una amplia aproximación al concepto de movilidad, desde un punto de vista introductorio, que nunca antes en nuestro ámbito había abarcado todos los aspectos que tienen que ver con él, desde cuestiones técnicas como los dispositivos móviles, sistemas operativos y navegadores, conectividad y estándares —cuya intención es poder comprender todos aquellos aspectos relacionados con la movilidad y que tienen una incidencia directa sobre los contenidos— hasta otras más relacionad...

  20. Apuntes sobre liderazgo

    OpenAIRE

    Contreras, Manuel E.

    2010-01-01

    Este trabajo presenta una breve síntesis de las principales teorías de liderazgo y se centra sobre el enfoque de liderazgo adaptativo de Ronald Heifetz. El documento originalmente fue desarrollado para las sesiones de educación a distancia de INDES. Ha sido revisado para usar en otros ámbitos de capacitación y ha sido utilizado en sesiones presenciales llevadas a cabo por INDES, como por otras entidades en universidades y centros de capacitación de America Latina.

  1. Sobre el razonamiento judicial

    OpenAIRE

    Asís Roig, Rafael de

    1998-01-01

    El trabajo elabora modelos a través de los cuáles es posible reconstruir la argumentación judicial plasmada en las sentencias y, a la vez, hacer explícitas las reglas que sirven de justificación a sus decisiones, y el marco normativo utilizado como referencia. El estudio analiza tanto los pronunciamientos sobre hechos como los que se refieren a la calificación jurídica, en principio, desde una perspectiva descriptiva. Ahora bien, también se llevan a cabo reflexiones y propuestas que van más a...

  2. Puente sobre el Rin

    Directory of Open Access Journals (Sweden)

    Gortz, Wilhelm

    1961-12-01

    Full Text Available Del total de 35 proyectos presentados al concurso del puente para carretera sobre el Rin, entre Duisburg-Ruhrort y Homberg, sólo dos proposiciones de la Demag fueron consideradas: Una con tablero suspendido por vientos que parten de dos torres, y otra, con suspensión por cables flexibles que se apoyan en dos torres y anclaje en la misma estructura. Por razones netamente estéticas fue elegida la propuesta Demag de puente suspendido por cables, aunque la solución con vientos hubiera sido la más económica, teniendo en cuenta las condiciones existentes.

  3. Uji Ketahanan Beberapa Varietas Jagung (Zea Mays l.)Terhadap Penyakit Karat Daun (Puccinia Polysora Underw.)Di Dataran Rendah

    OpenAIRE

    Irawan, Denny

    2016-01-01

    Denny Irawan, “ Resistance Test of Maize Varieties (Zea mays L.) to Leaf Rust Disease Attack (Puccinia polysora Underw.) In the Lowlands”. Supervised by Dr. Ir. Hasanuddin, MS and Ir. Lahmuddin Lubis, MP. This study aims to determine the resistance of some varieties of maize (Zea mays L.) to leaf rust disease (Puccinia polysora Underw.) in the lowlands. Research conducted in the village of Tanjung Selamat, Medan. Research using randomized block design with 10 treatments and three replications...

  4. Evaluación del crecimiento del maíz ( Zea mays L.) en función de dos técnicas de riego y diferentes niveles de nitrógeno

    OpenAIRE

    Tomás Díaz V.; Nicolás Wilfredo Pérez D.; Federico Páez O.; Aldo López G.; Leopoldo Partidas R.

    2007-01-01

    La presente contribución se refiere al uso más adecuado de las tecnologías de riego y la aplicación de nitrógeno en la producción de maíz (Zea mays L.). Por lo que, el objetivo fue determinar la influencia sobre el índice de área foliar (IAF), la producción de biomasa y rendimiento de grano cuando el cultivo de maíz es manejado mediante dos técnicas de riego y dos niveles de nitrógeno. Se utilizó un diseño en parcelas divididas, la parcela grande consistió en dos técnicas de riego y ...

  5. Evaluación del crecimiento del maíz ( Zea mays L.) en función de dos técnicas de riego y diferentes niveles de nitrógeno

    OpenAIRE

    Tomás Díaz V.; Nicolás Wilfredo Pérez D.; Federico Páez O.; Aldo López G.; Leopoldo Partidas R.

    2007-01-01

    La presente contribución se refiere al uso más adecuado de las tecnologías de riego y la aplicación de nitrógeno en la producción de maíz (Zea mays L.). Por lo que, el objetivo fue determinar la influencia sobre el índice de área foliar (IAF), la producción de biomasa y rendimiento de grano cuando el cultivo de maíz es manejado mediante dos técnicas de riego y dos niveles de nitrógeno. Se utilizó un diseño en parcelas divididas, la parcela grande consistió en dos técnicas de riego y la parcel...

  6. Sobre la tragedia griega

    Directory of Open Access Journals (Sweden)

    Mauricio Vélez Upegui

    2015-01-01

    Full Text Available Luego de caracterizar la tragedia griega clásica como expresión de un arte ciudadano que participa por igual de un carácter festivo, cierto régimen discursivo y una clara inscripción físico-espacial, el texto se demora en considerar tres aspectos fundamentales de esta forma dramática inventada por los griegos, a saber: una exposición sobre las fuentes orales míticas de las que los autores echan mano para componer la historia de cada una de las piezas que son llevadas a escena al amparo de un espíritu agonal; una explicación del funcionamiento formal de la tragedia, basado en la alternancia de partes cantadas (coro y partes recitadas (héroe; y, finalmente, una acotación sobre el sentido –interno y externo– que la acción dramática posee, en tanto elemento articulador de la trama.

  7. Sobre historia mundial hoy

    Directory of Open Access Journals (Sweden)

    Vera Weiler

    2010-08-01

    Full Text Available Los procesos de globalización son una realidad; su enorme impacto sobre la vida humana los ha convertido en un tema recurrente sobre el que se escribe y se comenta a diario también en Colombia. Los libros que de ellos tratan, ante todo los que 10 hacen en tono crítico, baten records en la industria editorial en todo el mundo. Las expectativas que acerca del futuro abrigan cientos de millones de personas se relacionan con 10 que ellas esperan, para bien o para mal, de la globalización. Las posturas que los gobernantes ocupan al respecto en el mundo son, cuando menos de aceptación, generalmente de activa participación en pos de la globalización. Por un lado, crece la preocupación y se multiplican las protestas; por el otro, dominan los razonamientos de los especialistas en materia de maximización de los rendimientos de los capitales que presentan la globalización, al estilo que se viene imponiendo, como el camino ineludible del gobierno universal de la eficiencia. ¿Tienen que decir algo los historiadores frente a todo esto?.

  8. Una revisión sobre el concepto de identidad del mexicano

    Directory of Open Access Journals (Sweden)

    José Martín Hurtado Galves

    2011-05-01

    Full Text Available El presente texto es una reflexión sobre la idea de identidad en México. Se estudia a cuatro filósofos mexicanos: Antonio Caso, José Vasconcelos, Samuel Ramos y Leopoldo Zea. El objetivo es revisar y replantear grosso modo sus ideas para compararlas con las diferentes realidades que hoy se viven en nuestro país. Las ideas, después de todo, no acaban de irse, en todo caso, regresan para hacernos ver y hablar desde lo que ya creíamos superado.The present text is a reflection on the idea of identity in Mexico. Envelope is reflected which are these on this subject four Mexican philosophers: Antonio Caso, Jose Vasconcelos, Samuel Ramos and Leopoldo Zea. The objective is to review and to reframe their ideas in order to compare them with the different realities that today are lived in our country. The ideas, after all, do not finish going away, in any case, they return to make us see and speak to us from which we believed already surpassed.

  9. Optimization of drying process of Zea Mays malt to use as alternative source of amylolytics enzymes

    Directory of Open Access Journals (Sweden)

    Joana Paula Menezes Biazus

    2005-06-01

    Full Text Available This work aimed to study the drying process optimization of maize (Zea Mays malt for obtaining maize malt, without affecting enzymatic activity of alpha e beta-amylases from maize malt. Results showed that dryer operation must occur in zone at 54°C and 5.18-6 h process time. The maize malt obtained had good enzymatic properties.Este trabalho objetivou a otimização da secagem do malte de milho (Zea Mays para obter um malte sem afetar a atividade das enzimas presentes neste, alfa e beta -amilases. Os resultados mostraram que a operação do secador deve ser feita a 54°C e entre 5,18-6 h de processo. O malte obtido possuiu boas propriedades enzimáticas.

  10. Results of Zea mays seeds β- irradiation in 0 - 5 Gy range

    International Nuclear Information System (INIS)

    In this study young plants, obtained from the control and beta irradiated seeds, were studied in laboratory experiments. Zea mays seeds with uniform genophond were irradiated with 90Sr source in the 0 - 5 Gy range. Increased germination percentage was observed under the influence of different radiation doses. We found that small doses of β- radiation have a stimulating effect on the growth of the plantlets, the maximum simulation (among the doses we used) being induced by 0.615 Gy and is statistically significant. We investigated the chlorophyll a to b ratio and the average length variations with the irradiation dose and present the results. Key words: b- radiation, Zea mays, germination rate, plants growth, photoassimilatory pigments,

  11. Inducing gravitropic curvature of primary roots of Zea mays cv Ageotropic

    Science.gov (United States)

    Moore, R.; Evans, M. L.; Fondren, W. M.

    1990-01-01

    Primary roots of the mutant 'Ageotropic' cultivar of Zea mays are nonresponsive to gravity. Their root caps secrete little or no mucilage and touch the root only at the extreme apex. A gap separates the cap and root at the periphery of the cap. Applying mucilage from normal roots or substances with a consistency similar to that of mucilage to tips of mutant roots causes these roots to become strongly graviresponsive. Gravicurvature stops when these substances are removed. Caps of some mutants secrete small amounts of mucilage and are graviresponsive. These results indicate that (a) the lack of graviresponsiveness in the mutant results from disrupting the transport pathway between the cap and root, (b) movement of the growth-modifying signal from the cap to the root occurs via an apoplastic pathway, and (c) mucilage is necessary for normal communication between the root cap and root in Zea mays cv Ageotropic.

  12. Influence of microgravity on cellular differentiation in root caps of Zea mays

    Science.gov (United States)

    Moore, R.; Fondren, W. M.; McClelen, C. E.; Wang, C. L.

    1987-01-01

    We launched imbibed seeds of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on cellular differentiation in root caps. The influence of microgravity varied with different stages of cellular differentiation. Overall, microgravity tended to 1) increase relative volumes of hyaloplasm and lipid bodies, 2) decrease the relative volumes of plastids, mitochondria, dictyosomes, and the vacuome, and 3) exert no influence on the relative volume of nuclei in cells comprising the root cap. The reduced allocation of dictyosomal volume in peripheral cells of flight-grown seedlings correlated positively with their secretion of significantly less mucilage than peripheral cells of Earth-grown seedlings. These results indicate that 1) microgravity alters the patterns of cellular differentiation and structures of all cell types comprising the root cap, and 2) the influence of microgravity on cellular differentiation in root caps of Zea mays is organelle specific.

  13. Influence of calcium phosphate nanoparticles, Piriformospora indica and Glomus mosseae on growth of Zea mays

    Science.gov (United States)

    Rane, Mansi; Bawskar, Manisha; Rathod, Dnyaneshwar; Nagaonkar, Dipali; Rai, Mahendra

    2015-12-01

    In this study, the arbuscular mycorrhizal fungus (G. mosseae) and endosymbiont (P. indica) colonized Zea mays were treated with calcium phosphate nanoparticles (CaPNPs) and evaluated for their plant growth promotion efficiency. It was observed that CaPNPs in combination with both G. mosseae and P. indica are more potent plant growth promoter than independent combinations of CaPNPs + G. mosseae, CaPNPs + P. indica or CaPNPs alone. The fluorimetric studies of treated plants revealed that CaPNPs alone and in combination with P. indica can enhance vitality of Zea mays by improving chlorophyll a content and performance index of treated plants. Hence, we conclude that CaPNPs exhibit synergistic growth promotion, root proliferation and vitality improvement properties along with endosymbiotic and arbuscular mycorrhizal fungi, which after further field trials can be developed as a cost-effective nanofertilizer with pronounced efficiency.

  14. Pengaruh Pupuk Hijau Krinyu (Chromolaena odorata L.) Terhadap Pertumbuhan Dan Produksi Jagung (Zea mays L.)

    OpenAIRE

    Junaida Damanik

    2009-01-01

    Penelitian ini bertujuan untuk mengetahui pengaruh pupuk hijau krinyu (Chromolaena odorata) terhadap pertumbuhan dan produksi tanaman jagung (Zea mays L). Penelitian ini dilaksanakan di areal ladang jagung milik rakyat di Desa Namo Rambe, dimulai pada bulan Agustus 2008 dan selesai pada bulan November 2008. Rancangan yang digunakan adalah Rancangan Acak Kelompok Non Faktorial yang terdiri dari 6 taraf yaitu T1 (Kontrol), T2 (Krinyu),T3 (Krinyu + N0 P60 K45), T4 (Krinyu + N60 P60 K...

  15. Genetic mechanisms underlying apimaysin and maysin synthesis and corn earworm antibiosis in maize (Zea mays L.).

    OpenAIRE

    Lee, E A; Byrne, P.F.; McMullen, M D; Snook, M E; Wiseman, B. R.; Widstrom, N W; Coe, E. H.

    1998-01-01

    C-glycosyl flavones in maize silks confer resistance (i.e., antibiosis) to corn earworm (Helicoverpa zea [Boddie]) larvae and are distinguished by their B-ring substitutions, with maysin and apimaysin being the di- and monohydroxy B-ring forms, respectively. Herein, we examine the genetic mechanisms underlying the synthesis of maysin and apimaysin and the corresponding effects on corn earworm larval growth. Using an F2 population, we found a quantitative trait locus (QTL), rem1, which account...

  16. Analysis of correlations and path effects for popping expansion in popcorn ( Zea mays var. everta Sturt.

    Directory of Open Access Journals (Sweden)

    Vijayabharathi A

    2009-12-01

    Full Text Available Correlation and path analysis involving 35 genotypes of popcorn (Zea mays var. everta Sturt. indicated thatdegree of popping alone exhibited positive association with popping expansion. The path analysis revealed thatcob weight showed very high positive direct effect on popping expansion followed by plant height, days tomaturity and days to 50% silking. Characters namely degree of popping, lesser cob length, cob girth and 100-kernel weight could be given greater emphasis while making selections for the improvement of poppingexpansion

  17. Allelopathic effects of ferulic, gallic, and vanillic acids on corn (Zea mays L.)

    OpenAIRE

    Abdaoui, Fatima El

    1991-01-01

    Studies on the activity of femlic, gallic, and vanillic acids on germination and growth of corn (Zea mays L.), radish (Raphanus sativus L.), and peanut (Arachis hypogaea L.) showed that the inhibitory effects of these acids were concentration and growth variable dependent. Ten days after treatment, significant reduction in percent germination of the three species occurred with higher phenolic acid treatments, except that gallic acid did not significantly inhibit peanut germi...

  18. Endophytic Phoma sp. isolated from medicinal plants promote the growth of Zea mays

    OpenAIRE

    ASHWINI KEDAR; DNYANESHWAR RATHOD; ALKA YADAV; GAURAVI AGARKAR; MAHENDRA RAI

    2014-01-01

    Kedar A, Rathod D, Yadav A, Agarkar G, Rai M. 2014. Endophytic Phoma sp. isolated from medicinal plants promote the growth of Zea mays. Nusantara Bioscience 6: 132-139. Fungal endophytes are reported as rich sources of valuable secondary metabolites and could be used as bio-fertilizers. In the present study, we report growth promotion potential of two Phoma species isolated from Tinospora cordifolia and Calotropis procera on maize. The fungal endophytes enhanced growth in inoculated maize pla...

  19. Expression Profiling of Selected Glutathione Transferase Genes in Zea mays (L.) Seedlings Infested with Cereal Aphids

    OpenAIRE

    Hubert Sytykiewicz; Grzegorz Chrzanowski; Paweł Czerniewicz; Iwona Sprawka; Iwona Łukasik; Sylwia Goławska; Cezary Sempruch

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2 •−) in infested Z. mays plants was ...

  20. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials

    OpenAIRE

    Mohamed Alburaki; Sébastien Boutin; Pierre-Luc Mercier; Yves Loublier; Madeleine Chagnon; Nicolas Derome

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were...

  1. Conservation and diversity of seed associated endophytes in Zea across boundaries of evolution, ethnography and ecology.

    Directory of Open Access Journals (Sweden)

    David Johnston-Monje

    Full Text Available Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte to modern maize (corn and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed

  2. The Effects of Different Mineral Nutrients on the levels of Cytokinins in Maize (Zea mays L.)

    OpenAIRE

    BATTAL, Peyami; TİLEKLİOĞLU, Bekir

    2001-01-01

    In this study, Z (trans-Zeatin) and ZR (trans-Zeatin Riboside) levels in the roots, stems, leaves, flowers and fruits of maize plants (Zea mays L.) were determined using high performance liquid chromatography (HPLC). Plants were grown in media containing macro elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulphur and iron) in optimum, deficient and excess concentrations. According to the average Z values for all periods, the highest Z levels were determined in the roots of pl...

  3. Conservation and Diversity of Seed Associated Endophytes in Zea across Boundaries of Evolution, Ethnography and Ecology

    OpenAIRE

    David Johnston-Monje; Raizada, Manish N

    2011-01-01

    Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorp...

  4. Some aspects of cultivation and utilization of waxy maize (Zea mays L. ssp. ceratina)

    OpenAIRE

    Agnieszka Klimek-Kopyra; Aleksander Szmigiel; Tadeusz Zając; Agnieszka Kidacka

    2012-01-01

    This paper is a review of available literature on Zea mays L.ssp.ceratina. It contains information on the origin, cul- tivation and utilization of waxy maize in the world and can be a contribution to the development of new research on maize cultivation and starch processing technology. Maize, as an old and economically important cereal, played an enormous role in the ancient civilisations of the New World. Among the maize subspecies compared, Z. mays ssp. indurata and Z. mays ssp. indenta...

  5. Analysis of correlations and path effects for popping expansion in popcorn ( Zea mays var. everta Sturt.)

    OpenAIRE

    Vijayabharathi A; C.R. Anandakumar; R.P. Gnanamalar

    2009-01-01

    Correlation and path analysis involving 35 genotypes of popcorn (Zea mays var. everta Sturt.) indicated thatdegree of popping alone exhibited positive association with popping expansion. The path analysis revealed thatcob weight showed very high positive direct effect on popping expansion followed by plant height, days tomaturity and days to 50% silking. Characters namely degree of popping, lesser cob length, cob girth and 100-kernel weight could be given greater emphasis while making selecti...

  6. Variability among maize (Zea mays L.) inbred lines for seed longevity

    OpenAIRE

    Revilla Temiño, Pedro; Velasco Pazos, Pablo; Malvar Pintos, Rosa Ana; Cartea González, María Elena; Ordás Pérez, Amando

    2006-01-01

    Genotypes conserved in active collections may suffer genetic erosion and modifications. The objective of this work was to investigate changes in germination and vigour in maize (Zea mays L.) inbred lines during cold storage in an active collection. Seeds of 16 maize inbreds produced along 16 years were evaluated for emergence and seedling vigour in a growth chamber. Linear and quadratic regressions of vigour and viability-related traits over seed age were calculated and tested for homogeneity...

  7. Abscisic acid is not necessary for gravitropism in primary roots of Zea mays

    Science.gov (United States)

    Moore, R.

    1990-01-01

    Primary roots of Zea mays L. cv. Tx 5855 treated with fluridone are strongly graviresponsive, but have undetectable levels of abscisic acid (ABA). Primary roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays are also graviresponsive despite having undetectable amounts of ABA. Graviresponsive roots of untreated and wild-type seedlings contain 286 to 317 ng ABA g-1 f. wt, respectively. These results indicate that ABA is not necessary for root gravicurvature.

  8. Movement of endogenous calcium in the elongating zone of graviresponding roots of Zea mays

    Science.gov (United States)

    Moore, R.; Cameron, I. L.; Smith, N. K.

    1989-01-01

    Endogenous calcium (Ca) accumulates along the lower side of the elongating zone of horizontally oriented roots of Zea mays cv. Yellow Dent. This accumulation of Ca correlates positively with the onset of gravicurvature, and occurs in the cytoplasm, cell walls and mucilage of epidermal cells. Corresponding changes in endogenous Ca do not occur in cortical cells of the elongating zone of intact roots. These results indicate that the calcium asymmetries associated with root gravicurvature occur in the outermost layers of the root.

  9. Pengaruh Pemberian Bahan Organik Terhadap Penyakit Pada Beberapa Varietas Tanaman Jagung (Zea Mays L) Di Lapangan

    OpenAIRE

    Sinda Maroganda Saragih

    2009-01-01

    SINDA MAROGANDA SARAGI “ Pengaruh Pemberian Bahan Organik terhadap penyakit pada beberapa varietas tanaman jagung ( zea mays L. ) di lapangan” Penelitian ini dilaksanakan di Lahan Pertanian Kampung Susuk dengan ketinggian tempat ± 25 m diatas permukaan laut. Penelitian ini menggunakan metode Rancangan Acak Kelompok (RAK) faktorial yang terdiri dari 2 faktor perlakuan dan 3 ulangan. Faktor 1 perlakuan dengan memberikan Bahan Organik yaitu B0 = tanpa bahan organik, B1 = 3 kg bahan organik ...

  10. Influence Of Plant Growth Promoting Rhizobacteria (pgpr) On Thegrowth Of Maize (zea Mays L.)

    OpenAIRE

    T. Sheela; Usharani

    2013-01-01

    Plant Growth Promoting Rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by wide variety of mechanism these includes direct and indirect mechanisms like phosphate solubilization, phytohormone production, antifungal activity, etc. The bacteria, were successfully isolated and characterized by morphological and biochemical methods as P. polymyxa. Subsequently to investigate the effect of PGPR isolates on the growth of maize (zea mays L.), a pot cultu...

  11. Iron oxide nanoparticles coated with β-cyclodextrin polluted of Zea mays plantlets

    Directory of Open Access Journals (Sweden)

    Mihaela Racuciu

    2012-01-01

    Full Text Available The present experimental investigation is focused on the study of assimilatory pigments and nucleic acid levels in young plants intended for agricultural use (Zea mays in presence of water based magnetic fluid added in culture medium. The magnetic fluid was constituted by coating the nanosized magnetic nanoparticles (with 10.55 nm average value of the physical diameter with β-cyclodextrin (C42H70O35 and further dispersion in water. After germination, various volume fractions (between 10 mL/L and 500 mL/L of the magnetic fluid was added daily in the culture medium of Zea mays plants still at their early ontogenetic stages. Toxicity symptoms leaded to brown spots covering the leaf surface for the highest magnetic fluid volume fractions used, a putative oxidative stress generated by iron excess treatment. Relatively small volume fraction of magnetic fluid solutions induced the increase of chlorophyll a level (up to 38%, the main photosynthesis pigment, as well that the nucleic acid level (up to 57% in Zea mays plantlets. All volume fractions of magnetic fluid solutions analyzed may have severe disruptive effects such as the ratio chlorophyll a/chlorophyll b (about 50% decreasing.

  12. Comparative toxicity of mycotoxins to navel orangeworm (Amyelois transitella) and corn earworm (Helicoverpa zea).

    Science.gov (United States)

    Niu, Guodong; Siegel, Joel; Schuler, Mary A; Berenbaum, May R

    2009-08-01

    Mycotoxins, such as aflatoxins and ochratoxins, are widely distributed in nature and are frequently problematic crop contaminants that cause millions of dollars of annual losses in the United States. Insect infestations of crop plants significantly exacerbate mycotoxin contamination. Damage to a variety of nut species by Amyelois transitella Walker (navel orangeworm, NOW) is associated with infection by Aspergillus species and concomitant production of aflatoxins and ochratoxins. Resistance to aflatoxins in this lepidopteran is compared here with the levels of resistance in Helicoverpa zea (corn earworm, CEW), another lepidopteran that routinely encounters aflatoxins in its diet, albeit at lower levels. Measured as the developmental delay caused by aflatoxin B1 (AFB1), it is apparent that the LC(50) (defined as the concentration preventing 50% of newly hatched larvae from entering the 2nd instar within 48 h) for AFB1 is 100 times greater for A. transitella than for H. zea. Similarly, A. transitella 1st instars display substantially higher tolerance to ochratoxin A, another mycotoxin contaminant produced by Aspergillus species, than do H. zea. Our studies indicate that A. transitella, although a hostplant generalist, may well be highly specialized for mycotoxin detoxification.

  13. Voz sobre frame relay

    OpenAIRE

    D´Elia, Gabriel Anibal

    2000-01-01

    Esta tesis trata el tema de VOFR, desde la digitalización de la voz hasta su transmisión a través de dicha red, así también como la comparación con otros medios de transporte como VOIP. Dada las características del protocolo frame relay y su disponibilidad se eligió como el medio más apropiado para la transmisión de voz y datos en forma integrada sobre una misma red. El trabajo comienza con una breve explicación de la voz, su digitalización y forma actual de transmisión a través de una red di...

  14. Excertos sobre o sedentarismo

    Directory of Open Access Journals (Sweden)

    Alexandre Palma

    2014-09-01

    Full Text Available O sedentarismo tem sido tratado como algo perfeitamente determinável, objetivo e, portanto, que pode ser apreendido. Por outro lado, o conceito de sedentarismo ainda permanece questionável e, por conseguinte, os instrumentos mostram-se inconsistentes. Neste sentido, o objetivo do presente estudo foi mostrar que diferentes discursos de verdade vêm concorrendo por esse conceito, o que nos motiva a pensar qual é a verdade ou, até mesmo, se há alguma verdade sobre ele. Após apresentarmos diferentes possibilidades de compreender o sedentarismo, através do uso de aforismos, entendemos que postular um discurso como verdade talvez apenas signifique que as pessoas nele creem e que há uma vontade de verdade como uma vontade voltada para o poder.

  15. VIGOR DE SEMENTES DE MILHO (Zea mays L. AVALIADO PELA PRECOCIDADE DE EMISSÃO DA RAIZ PRIMÁRIA EVALUATION OF CORN (Zea mays L. SEED VIGOR THROUGH THE PRECOCITY OF PRIMARY ROOT EMISSION

    Directory of Open Access Journals (Sweden)

    Francisco Ferraz de Toledo

    1999-01-01

    Full Text Available Foi desenvolvido trabalho baseado na determinação da precocidade da emissão da raiz primária de sementes de milho, em dez lotes de um mesmo cultivar. Este processo constou da distribuição de 200 sementes de cada lote sobre folhas de papel umedecido e, também, rolos de papel, que permaneceram em germinador a 25 °C; de 12 em 12 horas, aquelas que apresentaram emissão da raiz primária foram removidas, contadas e anotadas. Para estabelecer comparação entre os métodos e os lotes, paralelamente, as sementes eram avaliadas através da determinação do grau de umidade, dos testes de germinação e de vigor (primeira contagem, teste de frio com solo e emergência de plântulas em campo. Concluiu-se que há possibilidade de se utilizar o teste de emissão da raiz primária, em rolos de papel, para a avaliação do vigor de sementes de milho.The objectives of this study were to evaluate the variability of the emission of seed radicle of corn (Zea mays L. and to establish indexes of primary root emission to test the vigor of commercial seed lots. Samples of corn seeds not treated with fungicides, were taken from ten lots of the same cultivar. Two hundred seeds from each lot were distributed on wetted paper towels and also within paper rolles at 25 °C. Each 12 hours, seeds with primary root emission were counted and removed. Indexes of primary root emission were calculated and compared to conventional laboratory tests (first count; accelerated aging; cold test and field emergence. It was concluded that the primary root emission test, in rolled paper towels can be of great value for evaluating the vigor of corn seeds.

  16. Sobre la muerte voluntaria

    Directory of Open Access Journals (Sweden)

    Juan Álvarez-Cienfuegos Fidalgo

    2012-03-01

    Full Text Available El problema de cómo morir en nuestra sociedad se ha convertido en una inquietud para los ciudadanos y la reflexión moral. Especialmcnte por dos razones: por el desarrollo de la tecnología médica y por el hecho de que la mayor parte de los fallecimientos tienen lugar fuera del hogar, donde tradicionalmente ocurra el deceso. El presente artículo tiene como objetivo acercarse a esta cuestión. Para ello, se parte de la autonomía del ciudadano, con derecho a decidir sobre lo que considera cuál sea su manera de vivir y de morir. A tal fin, se hace una breve introducción sobre el dolor, el suicidio y la muerte, desde un punto de vista antropológico, pasando, después, a mostrar las cuestiones relacionadas con el problema de la eutanasia, donde la atención se dirigirá, ante todo, al enjuiciamiento crítico del tenso equilibrio en el que se mantienen dos principios fundamentales de la bioética: el de no maleficencia y el de autonomía del ciudadano.The problem of how to die in modern society has become a concern for both the citizen and moral reflection for two reasons in particular: due to developments in medical technology, and because most deaths occur outside the honre, where they traditionaÍlY took place. This paper addresses this issue, starting from citizen autonomy, the right to decide on what s/he considers to be his or her way of living and dying. To this end, a brief introduction considers pain, suicide and death from an anthropological viewpoint. Questions related to the problem of euthanasia are then exposed, with particular attention to, above all the critical judgement of the tense balance in which two fundamental principies of bioethics are held, the principle of non-maleficence and that of citizen autonomy.

  17. Effect of emamectin benzoate on mortality, proboscis extension, gustation and reproduction of the corn earworm, Helicoverpa zea.

    Science.gov (United States)

    López, Juan D; Latheef, M A; Hoffmann, W C

    2010-01-01

    Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult feeding approach. This approach entails the use of a feeding attractant and stimulant in combination with a toxicant that when ingested by the adult will either reduce fecundity/fertility at sub-lethal dosages or kill the adult. The intent of this study was to assess reproductive inhibition and toxicity of emamectin benzoate on H. zea when ingested by the adults when mixed in ppm active ingredient (wt:vol) with 2.5 M sucrose as a feeding stimulant. Because the mixture has to be ingested to function, the effect of emamectin benzoate was also evaluated at sub-lethal and lethal concentrations on proboscis extension and gustatory response of H. zea in the laboratory. Feral males captured in sex pheromone-baited traps in the field were used for toxicity evaluations because they were readily available and were more representative of the field populations than laboratory-reared adults. Laboratory-reared female moths were used for reproduction effects because it is very difficult to collect newly emerged feral females from the field. Emamectin benzoate was highly toxic to feral H. zea males with LC(50) values (95% CL) being 0.718 (0.532-0.878), 0.525 (0.316-0.751), and 0.182 (0.06-0.294) ppm for 24, 48 and 72 h responses, respectively. Sub-lethal concentrations of emamectin benzoate did not significantly reduce proboscis extension response of feral males and gustatory response of female H. zea. Sublethal concentrations of emamectin benzoate significantly reduced percent larval hatch of

  18. Sobre el nombre "Quechua"

    Directory of Open Access Journals (Sweden)

    Rodolfo Cerrón-Palomino

    1985-06-01

    Full Text Available Uno de los primeros problemas con el que a menudo tropiezael estudioso de los idiomas ágrafos, como es el caso de las lenguasaborígenes de América, es el de su denominación (glotónimo.En la medida ,en que, por razones históricas, las noticias sobretales lenguas, y por consiguiente los primeros estudios sobre lasmismas, surgen a partir del contacto con los miembros de la civilización occidental, los nombres de los distintos idiomas, así comode los grupos étnicos que los manejan, son el resultado casi siempre arbitrario cie designaciones fortuitas hechas por viajeros, misiioneros y exploradores, quienes por lo general se basan, para ello, bien en descripciones físicas de los grupo étnicos, en ciertos indios geográficos que constituyen el habitat de los mismos, e incluso en prejuicios que se nutren de un marcado europocentrismo.

  19. Refletindo sobre idosos institucionalizado

    Directory of Open Access Journals (Sweden)

    Cenir Gonçalves Tier

    2004-06-01

    Full Text Available Trata-se de uma pesquisa qualitativa, descritiva que teve por objetivo identificar como vem sendo o relacionamento idoso-família, identificando os motivos que levaram os familiares a optarem pela institucionalização do seu idoso, obtendo-se também a visão da família sobre o cuidado no lar. Para coleta dos dados utilizou-se um instrumento com perguntas abertas. A coleta dos dados efetivou-se nos meses de agosto de 2002 a julho de 2003, sendo sujeitos da pesquisa, familiares de idosos de uma instituição asilar em um município da região noroeste do Rio Grande do Sul. Através da análise de conteúdo constatou-se que a maior dificuldade encontrada pela família, visando dispensar cuidados ao idoso é a "falta de tempo para cuidar" do seu familiar idoso, pois a maioria deles exige cuidados em tempo integral.

  20. Caracterização da atividade amilásica do malte de milho (Zea mays L.) = Characterization of amylase activity from maize (Zea mays L.) malt

    OpenAIRE

    Joana Paula Menezes Biazus; José Carlos Curvelo Santana; Roberto Rodrigues de Souza; Elias Basile Tambourgi

    2006-01-01

    Este trabalho objetivou estudar o processo de germinação e a caracterização da atividade bioquímica das amilases do malte de milho (Zea mays L.) para gerar uma fonte de amilase de baixo custo e boa atividade enzimática. A atividade enzimática foi monitorada todos os dias durante a germinação das sementes para se obter a melhor condição de produção do malte. Os resultados mostraram que a atividade enzimática nas sementes foi maior no 4º. dia de germinação. A caracterização bioquímica mostrou q...

  1. Caracterização da atividade amilásica do malte de milho (Zea mays L. = Characterization of amylase activity from maize (Zea mays L. malt

    Directory of Open Access Journals (Sweden)

    Joana Paula Menezes Biazus

    2006-01-01

    Full Text Available Este trabalho objetivou estudar o processo de germinação e a caracterização da atividade bioquímica das amilases do malte de milho (Zea mays L. para gerar uma fonte de amilase de baixo custo e boa atividade enzimática. A atividade enzimática foi monitorada todos os dias durante a germinação das sementes para se obter a melhor condição de produção do malte. Os resultados mostraram que a atividade enzimática nas sementes foi maior no 4º. dia de germinação. A caracterização bioquímica mostrou que as amilases do malte apresentam faixa ótima de pH entre 4,3 e 6, com temperaturas ótimas a 50°C e 80ºC e os valores de Km e Vmax para hidrólise do amido foram de 7,69.10-2 g/L e 7,69.102g/L.min, respectivamente.This work aimed to study the germination process and characterization of the amylolytic activity of the maize (Zea mays L. malt aiming to obtain source amylases at lower cost. Enzymatic activity was monitored all days during the seed germination, for obtaining thebest condition of malt production. Results showed that the enzymatic activity from maize seeds was larger in 4° germination day. Enzymes characterization showed that the maize malt amylases have optimal zone of pH between 4.3 and 6, with optimal temperatures of 50°C and 80ºC. The Km and Vmax values for starch hydrolysis were 7.69.10-2 g/L and 7.69.102g/L.min, respectively.

  2. Recovery of Lead(II from Aqueous Solutions by Zea mays Tassel Biosorption

    Directory of Open Access Journals (Sweden)

    Caliphs M. Zvinowanda

    2010-01-01

    Full Text Available Problem statement: Major adsorbent materials used in heavy metal ion removal from polluted aqueous streams are expensive and difficult to regenerate. In this study, the possibility of using Zea mays tassel, as an alternative low cost biosorbent material to remediate heavy metal pollution was investigated. Lead (II was used because of its wide application in industrial products and well documented toxicity. Approach: Tassel was obtained from mature Zea mays cultivar R52 hybrid plants. The tassel was milled to a powder and was used to adsorb lead(II ions from simulated solutions in batch experiments. The desorption of lead(II was carried out using nitric acid and sodium citrate solutions. The adsorbent was characterized by FTIR, EDX and ESCA before and after application of lead(II solutions. Results: For samples with concentrations of 100 mg L-1 Pb(II, 94-98% was adsorbed and 57-74 and 57-67% recoveries were achieved with 0.5-5 M nitric acid and 0.01-0.2 M sodium citrate as the stripping solutions, respectively. EDX spectrum of pure tassel indicated that group 1 and 2 metals were the major exchangeable ions present on its surface. ESCA analysis picked up small amounts of lead(II in the form of Pb(OH+ and Pb(NH+ ions on the surface of tassel adsorbent exposed to Pb2+ ions and none on pure tassel sample. Functional groups such as -H, -NH2, -C = O and -COOH which are polar and are legends which are capable of binding heavy metals were identified by FTIR. Conclusion: The potential of Zea mays tassel to adsorb and recover heavy metals from aqueous solution was successfully demonstrated with Pb(II sample solutions. The results obtained thus far demonstrated the possibility of using tassel powder in the removal as well as recovery of metals from aqueous solutions.

  3. Enhanced Mineral Uptake by Zea mays and Sorghum bicolor Roots Inoculated with Azospirillum brasilense†

    OpenAIRE

    Lin, Willy; Okon, Yaacov; Hardy, Ralph W. F.

    1983-01-01

    Inoculation of corn (Zea mays) seeds with Azospirillum brasilense strain Cd or Sp 7 significantly enhanced (30 to 50% over controls) the uptake of NO3−, K+, and H2PO4− into 3- to 4-day- and 2-week-old root segments. No gross changes in root morphology were observed; altered cell arrangement in the outer four or five layers of the cortex was seen in photomicrographs of cross sections of inoculated corn roots. The surface activity involved in ion uptake probably increased, as shown by the darke...

  4. Life Cycle of Heterodera zeae Koshy, Swarup, and Sethi on Zea mays L. Axenic Root Explants

    OpenAIRE

    Lauritis, J. A.; Rebois, R. V.; Graney, L. S.

    1983-01-01

    Monoxenic cultures of Heterodera zeae, the corn cyst nematode (CCN), were established on root explants of corn Zea mays L., cv. Kenworthy. The life cycle of H. zeae was determined from light anti scanning electron microscopic observations of the root explants grown in the dark at 29.5 ± .5 C under gnotobiotic conditions. The life cycle, from the time the explants were inoculated with second-stage larvae (L2) to the first appearance of newly hatched second-generation L2, required 22 days. The ...

  5. Effect of salt stress on some sweet corn (Zea mays L. var. saccharata) genotypes

    OpenAIRE

    Shtereva Lydia A.; Vassilevska-Ivanova Roumiana D.; Karceva Tanya V.

    2015-01-01

    An experiment was carried out hydroponically under laboratory conditions to investigate the effect of salt stress on several physiological and biochemical parameters of three sweet corn (Zea mays L. var. saccharata) genotypes: lines 6-13, C-6 (pollen source) and their heterotic F1 hybrid “Zaharina”. The degree of salinity tolerance among these genotypes was evaluated at three different sodium chloride (NaCl) concentrations: 0 mM, 100 mM, 125 mM and 150 mM. ...

  6. Comparative Effects Of Processing On The Cyanide Content Of Manihot Esculenta , Glycine Max And Zea Mays

    OpenAIRE

    Onyeike E.N; Nwaichi E. O.; Ibigomie C.E

    2013-01-01

    The effects of varying processing treatments on the cyanide content of Manihot Esculenta, Zea Mays and Glycine Max were determined using picrate kit method and the following mean concentrations in ppm were obtained: 0.10, 0.00, 0.00, 0.00, 0.01, 0.00, 0.02,0.00, and 0.00 for Cassava, Garri, Fufu, Tapioka, Soybean, Vitamilk, Raw maize, Roasted maize, and Boiled maize respectively. There were statistically significant differences (P ≤ 0.05) among all raw samples analysed for t...

  7. Effects of N fertilizer on root growth in Zea mays L. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z. R.; Rui, Y. R.; Shen, J. B.; Zhang, F. S.

    2008-07-01

    This paper reports the effects of different nitrogen (N) fertilizer levels on the growth of maize (Zea mays L.) under field conditions. The N supply was found to influence the growth of the plants, especially the roots. A high N supply significantly inhibited root elongation, and was associated with reduced root dry weight compared to controls and to plants grown with smaller supplies of N. However, no differences were seen in lateral primary root density under the different N supply conditions, nor did plant N concentration increase with high N supply. In conclusion, a high N supply not only wastes resources and pollutes the environment, it may also inhibit root growth. (Author)

  8. Cytogenetics of monosomes in Zea mays. Comprehensive report, October 1, 1970--January 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D. F.

    1976-10-01

    Monosomics (organisms lacking one chromosome) are perhaps the most interesting of the aneuploid types because a chromosome lacks a pairing partner in each meiotic cell and because genes on an entire chromosome are present in the hemizygous condition in each meiotic cell. A recently-discovered system produces a high frequency of monosomics in a Zea mays (maize). With this system, monosomics are available in a diploid organism in relatively large numbers and for most of the chromosomes for the first time. Results are reported from studies on several aspects of the cytogenetics of monosomics.

  9. Preliminary study on effects of nitrogen ion implantation on corn (Zea mays) somatic cell culture

    International Nuclear Information System (INIS)

    Immature embryos from three self-bred series of M1 corn (Zea mays) were cultured in MN and AG medium after dry seeds were implanted to 2 x 1016 cm-2 N+ ions of 60 keV and grown into M1 plants. The experiments indicated that all genotypes formed pale-yellow or yellow callus in the two media. The average callus induction frequency of M1 immature embryos was 11.7% higher than that of the control. Percentages of callus were different not only for various genotypes of the culture material in the two media, but also for different concentration of 2,4-D and 6-BA

  10. THE INFLUENCE OF GRAMOXONE HERBICIDE ON THE CONTENT OF THE PHOTOSYNTHETIC PIGMENTS IN ZEA MAYS

    Directory of Open Access Journals (Sweden)

    Antoanela Patras

    2007-08-01

    Full Text Available The active substance of Gramoxone herbicide is interacting with plant’s photosynthetic systems, playing the role of final acceptor of the photosynthetic electrons. Except this known mode of action, it has been also observed the inhibitory action on the protoporphyrinogen oxidase – essential enzyme for chlorophylls biosynthesis, and also the decrease of photosynthetic pigment’s concentration in some spontaneous plants. Based on these prerequisites, the present study demonstrates the decrease of the photosynthetic pigment’s content in Zea mays in the presence of Gramoxone.

  11. Cinética de rehidratación y deterioro biológico en Zea mays almacenado a una Humedad Relativa del Aire Intergranular (HRAI del 92%

    Directory of Open Access Journals (Sweden)

    Eguiazu, G. M.

    1993-12-01

    Full Text Available Maize grains (Zea mays var indurata «Plata» tipe destined to commercialization were submitted to a relative humidity of the intergranular air of 92% during 120 days to 25 °C. The kinetics of rehydration, humidity and biological damage («mouldy» «blue eye» and «spoiled» was determined. After 14 to 17 days, the sample rehydrates on the basis of commercialization of 14,5% of humidity and in the same period a degree of standard of commercial quality is lost. It is established that the basis of commercialization of 14,5% is very near the limit which favours the biological damage.Granos de maíz (Zea mays var. indurata tipo «Plata», destinado a comercialización, fueron sometidos a una Humedad Relativa del Aire Intergranular del 92% a 25 °C durante 120 días. Se determinó la cinética de rehidratación, humedad y el deterioro biológico («Verdín» y «Dañado». Se observó que luego de 14 a 17 días la muestra se rehidrató por sobre la base de comercialización del 14,5% de humedad y en el mismo periodo se pierde un grado en el estandard de calidad comercial. Se plantea que la base de comercialización del 14,5% se halla muy cercana al límite que favorece el deterioro biológico.

  12. Chromium accumulation potential of Zea mays grown under four different fertilizers.

    Science.gov (United States)

    Dheeba, B; Sampathkumar, P; Kannan, K

    2014-12-01

    Chromium (Cr) contamination in soil is a growing concern in sustainable agriculture production and food safety. We performed pot experiment with chromium (30 mg/soil) to assess the accumulation potential of Zea mays and study the influence of four fertilizers, viz. Farm Yard Manure (FYM), NPK, Panchakavya (PK) and Vermicompost (VC) with respect to Cr accumulation. The oxidative stress and pigment (chlorophyll) levels were also examined. The results showed increased accumulation of chromium in both shoots and roots of Zea mays under FYM and NPK supply, and reduced with PK and VC. While the protein and pigment contents decreased in Cr treated plants, the fertilizers substantiated the loss to overcome the stress. Similarly, accumulation of Cr increased the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) indicating the enhanced damage control activity. However, these levels were relatively low in plants supplemented with fertilizers. Our results confirm that the maize can play an effective role in bioremediation of soils polluted with chromium, particularly in supplementation with fertilizers such as farm yard manure and NPK.

  13. IDENTIFICATION OF LECTINS OF ZEA MAYS RAW MATERIAL AND THE STUDY OF LECTIN ACTIVITY

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    Karpiuk UV

    2013-03-01

    Full Text Available The aime of the study was to identify lectins in the Zea mays raw material: roots, stems, heads, leaves and corn silk and study their activity. Lectins activity has been studied using the biological method of ratuserytroagglutination. This method is based on formation of aggregates of lectins and rats erythrocytes. The activity unit was the floor amount of lectins that agglutinate erythrocytes. The protein nature of extracts that agglutinate has been determined using Bradford method. The lectins activity of Zea mays roots was 6,21±0,11 unit/mg of protein; of heads – 2,61±0,17 unit/mg of protein; of leaves – 0,62 ±0,05 unit/mg of protein; of corn silk – 1,06±0,08 unit/mg of protein; of stems – 0,97±0,09 unit/mg of protein. The greatest lectins activity was in leaves, stems and corn silk.

  14. Effects of Different Nitrogen Application Strategies on Yield and Forage Nutritive Quality of Zea mexicana

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-jun; WANG Kong-jun; YUAN Cui-ping; XU Hong

    2004-01-01

    A pool experiment was carried out to study the effects of different nitrogen application strategies (rates and stages of nitrogen application) on yield and forage nutritive quality of Zea mexicana cultivated in summer, 2002. In the whole growing stage, its stem was clipped three times at the height of 25 cm when it was 110 cm high (H1, H2 and H3 stand for the first, second and third harvest stage, respectively). Six indexes including crude protein (CP), ether extract (EE), nitrogen free extract (NFE), acid detergent fiber (ADF), crude ash (CA), and general energy (GE) were employed to evaluate the forage nutritive value. The results showed that the content of CP and EE increased but the content of CA and ADF decreased under the two nitrogen rates (High-rate N, 600 kg ha-1;Mid-rate N, 300 kg ha-1). The fresh and dry harvest biomass of the whole plants on H1 and those of the leaves on H2 were also improved. But the stalks on H2 and the whole plants on H3 were affected mainly by dressing nitrogen fertilizer. The yield of CP and EE, CA,NFE, and GE was mainly affected by nitrogen rates. The ADF yield increased was due to the increment of the fresh and dry harvest biomass. Nitrogen applied as base fertilizer for summer Zea mexicana can be harvested a higher biomass and improve the forage nutritive quality.

  15. Effects of Different Nitrogen Application Strategies on Yield and ForageNutritive Quality of Zea mexicana

    Institute of Scientific and Technical Information of China (English)

    WANGYong-jun; WANGKong-jun; YUANCui-ping; XUHong

    2004-01-01

    A pool experiment was carried out to study the effects of different nitrogen application strategies (rates and stages of nitrogen application) on yield and forage nutritive quality of Zea mexicana cultivated in summer, 2002. In the whole growing stage, its stem was clipped three times at the height of 25 cm when it was II0 cm high (H1, H2 and H3 stand for the first, second and third harvest stage, respectively). Six indexes including crude protein (CP), ether extract (EE), nitrogen free extract (NFE), acid detergent fiber (ADF), crude ash (CA), and general energy (GE) were employed to evaluate the forage nutritive value. The results showed that the content of CP and EE increased but the content of CA and ADF decreased under the two nitrogen rates (High-rate N, 600 kg ha-1;Mid-rate N, 300 kg ha-1). The fresh and dry harvest biomass of the whole plants on H1 and those of the leaves on H2 were also improved. But the stalks on H2 and the whole plants on H3 were affected mainly by dressing nitrogen fertilizer. The yield of CP and EE, CA,NFE, and GE was mainly affected by nitrogen rates. The ADF yield increased was due to the increment of the fresh and dry harvest biomass. Nitrogen applied as base fertilizer for summer Zea mexicana can be harvested a higher biomass and improve the forage nutritive quality.

  16. Hormetic effect(s) of tetracyclines as environmental contaminant on Zea mays

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, Luciana; Godeas, Feliciana [Dipartimento di Biologia, Universita Tor Vergata, Rome (Italy); De Filippis, Stefania Paola [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy); Mantovi, Paolo [Centro Ricerche Produzioni Animali, Reggio Emilia (Italy); Barchi, Davide [Assessorato all' Agricoltura, Regione Emilia-Romagna, Bologna (Italy); Testa, Cecilia; Rubattu, Nicolino [Istituto Zooprofilattico Sperimentale della Sardegna, Sassari (Italy); Brambilla, Gianfranco, E-mail: gianfranco.brambilla@iss.i [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy)

    2010-01-15

    Animal wastes from intensive pig farming as fertilizers may expose crops to antimicrobials. Zea mays cultivations were carried out on a virgin field, subjected to dressing with pig slurries contaminated at 15 mg L{sup -1} of Oxy- and 5 mg L{sup -1} of Chlor-tetracycline, and at 8 mg L{sup -1} of Oxy and 3 mg L{sup -1} of Chlor, respectively. Pot cultivation was performed outdoor (Oxy in the range 62.5-1000 ng g{sup -1} dry soil) and plants harvested after 45 days. Tetracyclines analyses on soils and on field plants (roots, stalks, and leaves) did not determine the appreciable presence of tetracyclines. Residues were found in the 45-day pot corn only, in the range of 1-50 ng g{sup -1} for Oxy in roots, accounting for a 5% carry-over rate, on average. Although no detectable residues in plants from on land cultivations, both experimental batches showed the same biphasic growth form corresponding to a dose/response hormetic curve. - Oxytetracycline in soils elicits a hormetic response in Zea mays plants.

  17. Chromium accumulation potential of Zea mays grown under four different fertilizers.

    Science.gov (United States)

    Dheeba, B; Sampathkumar, P; Kannan, K

    2014-12-01

    Chromium (Cr) contamination in soil is a growing concern in sustainable agriculture production and food safety. We performed pot experiment with chromium (30 mg/soil) to assess the accumulation potential of Zea mays and study the influence of four fertilizers, viz. Farm Yard Manure (FYM), NPK, Panchakavya (PK) and Vermicompost (VC) with respect to Cr accumulation. The oxidative stress and pigment (chlorophyll) levels were also examined. The results showed increased accumulation of chromium in both shoots and roots of Zea mays under FYM and NPK supply, and reduced with PK and VC. While the protein and pigment contents decreased in Cr treated plants, the fertilizers substantiated the loss to overcome the stress. Similarly, accumulation of Cr increased the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) indicating the enhanced damage control activity. However, these levels were relatively low in plants supplemented with fertilizers. Our results confirm that the maize can play an effective role in bioremediation of soils polluted with chromium, particularly in supplementation with fertilizers such as farm yard manure and NPK. PMID:25651615

  18. Analysis of the Genome of the Sexually Transmitted Insect Virus Helicoverpa zea Nudivius 2

    Directory of Open Access Journals (Sweden)

    Zhiqiang Lu

    2012-01-01

    Full Text Available The sexually transmitted insect virus Helicoverpa zea nudivirus 2 (HzNV-2 was determined to have a circular double-stranded DNA genome of 231,621 bp coding for an estimated 113 open reading frames (ORFs. HzNV-2 is most closely related to the nudiviruses, a sister group of the insect baculoviruses. Several putative ORFs that share homology with the baculovirus core genes were identified in the viral genome. However, HzNV-2 lacks several key genetic features of baculoviruses including the late transcriptional regulation factor, LEF-1 and the palindromic hrs, which serve as origins of replication. The HzNV-2 genome was found to code for three ORFs that had significant sequence homology to cellular genes which are not generally found in viral genomes. These included a presumed juvenile hormone esterase gene, a gene coding for a putative zinc-dependent matrix metalloprotease, and a major facilitator superfamily protein gene; all of which are believed to play a role in the cellular proliferation and the tissue hypertrophy observed in the malformation of reproductive organs observed in HzNV-2 infected corn earworm moths, Helicoverpa zea.

  19. Knob-associated tandem repeats on mitotic chromosomes in maize, Zea diploperennis and their hybrids

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; GAO Yuan; HE Guanyuan; GU Mingguang; GUO Lequn; SONG Yunchun

    2004-01-01

    Knob-associated tandem repeats, 180-bp repeats and TR-1 elements, together with 45S rDNA were located on mitotic chromosomes of Zea diploperennis (DP),maize inbred line F102 and their hybrid. In DP, knobs on the short arm of chromosomes 1 and 4 and on the long arm of the chromosomes 4 and 5 are composed predominantly of the 180-bp repeats. In addition, 180-bp repeats existed together with TR-1 elements were also detected on the short arm of chromosomes 2 and 5 and on the long arm of the chromosomes 2, 6, 7, 8 and 9. In maize inbred line F102, 180-bp repeats were present in chromosomes 7S and one homologue of chromosomes 8L. TR-1 elements appeared on satellite of chromosome 6 and no detectable hybridization site co-located with 180-bp repeats was observed in maize F102. Polymorphism of size, number, and distribution of 180-bp and TR-1 signals were revealed among different chromosomes in these two species and heteromorphism existed between some homologous chromosomes in the same species.Using these excellent landmarks, the interspecific hybrid of maize and DP were identified. The results suggest that comparative analysis of 180-bp repeats and TR-1 elements may help understand the genome organization and the evolution in Zea.

  20. De novo assembly ofZea nicaraguensis root transcriptome identiifed 5261full-length transcripts

    Institute of Scientific and Technical Information of China (English)

    JIANG Wei; LIU Hai-lan; WU Yuan-qi; ZHANG Su-zhi; LIU Jian; LU Yan-li; TANG Qi-lin; RONG Ting-zhao

    2016-01-01

    Zea nicaraguensis, a wild relative of cultivated maize (Zea mayssubsp. mays), is considered to be a valuable germplasm to improve the waterlogging tolerance of cultivated maize. Use of reverse genetic-based gene cloning and function veriif-cation to discover waterlogging tolerance genes inZ. nicaraguensis is currently impractical, because little gene sequence information forZ. nicaraguensis is available in public databases. In this study,Z. nicaraguensis seedlings were subjected to simulated waterlogging stress and total RNAs were isolated from roots stressed and non-stressed controls. In total, 80 mol L–1 Ilumina 100-bp paired-end reads were generated.De novo assembly of the reads generated 81002 ifnal non-re-dundant contigs, from which 5261 full-length transcripts were identiifed. Among these full-length transcripts, 3169 had at least one Gene Ontology (GO) annotation, 2354 received cluster of orthologous groups (COG) terms, and 1992 were assigned a Kyoto encyclopedia of genes and genomes (KEGG) Orthology number. These sequence data represent a valuable resource for identiifcation ofZ. nicaraguensisgenes involved in waterlogging response.

  1. The deuterium depleted water effects on germination, growth and respiration processes in Zea Mays culture

    International Nuclear Information System (INIS)

    The aim of this paper is to study the influence of deuterium depleted water (DDW) on the germination, growth and respiration processes in Zea Mays culture. The DDW is produced by the Institute of Cryogenics and Isotope Separation, Rm. Valcea (Romania). We used moist seeds in three experimental lots: L-1 (control), using distillated water (because the quality of DDW, excepting the deuterium content, is similar to that of distillated water); L-2, using a mixture of DDW and H2O in 1:1 proportion; L-3, germination in light water (DDW). Reported to the control lot, the germinative energy was higher in L-2 and L-3, but it was no significant difference between faculty of germination of variants. The length of main root was higher in L-2 and L-3 as compared to control lot. The intensity process of respiration was stimulated when DDW was used in both cases (L-2 or L-3). So, we can remark a favorable influence of light water on some biological processes in Zea mays plants (authors)

  2. Preventive Effect of Zea mays L. (Purple Waxy Corn on Experimental Diabetic Cataract

    Directory of Open Access Journals (Sweden)

    Paphaphat Thiraphatthanavong

    2014-01-01

    Full Text Available Recently, substances possessing antioxidant can prevent cataractogenesis of diabetic cataract. Therefore, this study was carried out to determine the anticataract effect of Zea mays L. (purple waxy corn, a flavonoids rich plant, in experimental diabetic cataract. Enucleated rat lenses were incubated in artificial aqueous humor containing 55 mM glucose with various concentrations of Zea mays L. (purple waxy corn ranging between 2, 10, and 50 mg/mL at room temperature for 72 h. At the end of the incubation period, the evaluation of lens opacification, MDA level, and the activities of SOD, CAT, GPx, and AR in lens were performed. The results showed that both medium and high doses of extract decreased lens opacity together with the decreased MDA level. In addition, medium dose of extract increased GPx activity while the high dose decreased AR activity. No other significant changes were observed. The purple waxy corn seeds extract is the potential candidate to protect against diabetic cataract. The mechanism of action may occur via the decreased oxidative stress and the suppression of AR. However, further research in vivo is still essential.

  3. Aldose Reductase Inhibitory Activity of Compounds from  Zea mays L.

    Directory of Open Access Journals (Sweden)

    Tae Hyeon Kim

    2013-01-01

    Full Text Available Aldose reductase (AR inhibitors have a considerable therapeutic potential against diabetes complications and do not increase the risk of hypoglycemia. Through bioassay-guided fractionation of an EtOH extract of the kernel from purple corn (Zea mays L., 7 nonanthocyanin phenolic compounds (compound 1–7 and 5 anthocyanins (compound 8–12 were isolated. These compounds were investigated by rat lens aldose reductase (RLAR inhibitory assays. Kinetic analyses of recombinant human aldose reductase (rhAR were performed, and intracellular galactitol levels were measured. Hirsutrin, one of 12 isolated compounds, showed the most potent RLAR inhibitory activity (IC50, 4.78 μM. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/substrate concentration, hirsutrin showed competitive inhibition against rhAR. Furthermore, hirsutrin inhibited galactitol formation in rat lens and erythrocytes sample incubated with a high concentration of galactose; this finding indicates that hirsutrin may effectively prevent osmotic stress in hyperglycemia. Therefore, hirsutrin derived from Zea mays L. may be a potential therapeutic agent against diabetes complications.

  4. Safe use of metal-contaminated agricultural land by cultivation of energy maize (Zea mays)

    International Nuclear Information System (INIS)

    Production of food crops on trace element-contaminated agricultural lands in the Campine region (Belgium) can be problematic as legal threshold values for safe use of these crops can be exceeded. Conventional sanitation of vast areas is too expensive and alternatives need to be investigated. Zea mays on a trace element-contaminated soil in the region showed an average yield of 53 ± 10 Mg fresh or 20 ± 3 Mg dry biomass ha−1. Whole plant Cd concentrations complied with legal threshold values for animal feed. Moreover, threshold values for use in anaerobic digestion were met. Biogas production potential did not differ between maize grown on contaminated and non-contaminated soils. Results suggested favorable perspectives for farmers to generate non-food crops profitably, although effective soil cleaning would be very slow. This demonstrates that a valuable and sustainable alternative use can be generated for moderately contaminated soils on which conventional agriculture is impaired. -- Highlights: •Zea mays on trace element-contaminated soil has an average yield of 20 ± 3 Mg DW ha−1. •Whole plant Cd concentrations complied with legal threshold values for animal feed. •Biogas production did not differ from maize grown on non-contaminated soils. •Perspectives are favorable for farmers to generate non-food crops profitably. •Effective soil cleaning would be very slow. -- Energy maize cultivation constitutes a sustainable alternative use of trace element-contaminated agricultural soils

  5. Genetic Variation for Resistance to Bacillus thuringiensis Toxins in Helicoverpa zea (Lepidoptera: Noctuidae) in Eastern North Carolina

    Science.gov (United States)

    In order to evaluate resistance to Bacillus thuringiensis Berliner toxins, female bollworm moths, Helicoverpa zea (Boddie), were collected from four light trap locations in two eastern North Carolina counties from August-October during 2001 and 2002. Moths were allowed to oviposit, and upon hatch, ...

  6. Promoting Student Inquiry Using "Zea Mays" (Corn) Cultivars for Hypothesis-Driven Experimentation in a Majors Introductory Biology Course

    Science.gov (United States)

    Blair, Amy C.; Peters, Brenda J.; Bendixen, Conrad W.

    2014-01-01

    The AAAS Vision and Change report (2011) recommends incorporating student research experiences into the biology curriculum at the undergraduate level. This article describes, in detail, how "Zea mays" (corn) cultivars were used as a model for a hypothesis-driven short-term research project in an introductory biology course at a small…

  7. Effect of emamectin benzoate on mortality, proboscis extension, gustation and reproduction of the corn earworm, Helicoverpa zea

    Science.gov (United States)

    Newly emerged bollworm adults, Helicoverpa zea (Boddie) require carbohydrate source from plant exudates and nectars for reproduction. Adults actively seek such feeding sites upon eclosion in their natural habitat. We wanted to evaluate this nocturnal behavior of the bollworm for potential use as a p...

  8. Water management options based on rainfall analysis for rainfed maize (Zea Mays L.) production in Rushinga district Zimbabwe

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.

    2011-01-01

    Maize (Zea mays L.), the dominant and staple food crop in Southern and Eastern Africa, is preferred to the drought-tolerant sorghum and pearl millet even in semi-arid areas. In semi-arid areas production of maize is constrained by droughts and poor rainfall distribution. The best way to grow crops i

  9. 玉米低磷胁迫研究现状%Research Situation of Low Phosphorus Stress in Zea mays

    Institute of Scientific and Technical Information of China (English)

    湛静; 陈发波

    2014-01-01

    玉米是世界第二大粮食作物,同时也是我国第一大农作物。磷是玉米生长发育所必需的元素之一,充当生物膜和核酸的重要组成元素,缺磷将严重影响玉米的生长发育。综述了缺磷对玉米苗期性状、根系、生理生化特性及产量等方面的影响。%Zea mays is not only the second largest food crops in the world ,but also the first major crops in China.Phosphorus ,one of the essential elements making up biofilm and nucleic acid ,is indispensable to Zea mays.Phosphorus deficiency will affect growth and development of Zea mays.This article summarized the effects of low phosphorus stress on seedling traits ,root,physiological and biochemistry characteristics ,and yield in Zea mays.

  10. TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

    Science.gov (United States)

    Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

  11. Molecular and biochemical analysis of the plastidic ADP-glucose transporter (ZmBT1) from Zea mays

    NARCIS (Netherlands)

    Kirchberger, S.; Leroch, M.; Huynen, M.A.; Wahl, M.; Neuhaus, H.E.; Tjaden, J.

    2007-01-01

    Physiological studies on the Brittle1 maize mutant have provided circumstantial evidence that ZmBT1 (Zea mays Brittle1 protein) is involved in the ADP-Glc transport into maize endosperm plastids, but up to now, no direct ADP-Glc transport mediated by ZmBT1 has ever been shown. The heterologous synth

  12. Molecular and biochemical analysis of the plastidic ADP-glucose transporter (ZmBT1) from Zea mays.

    NARCIS (Netherlands)

    Kirchberger, S.; Leroch, M.; Huynen, M.A.; Wahl, M.; Neuhaus, H.E.; Tjaden, J.

    2007-01-01

    Physiological studies on the Brittle1 maize mutant have provided circumstantial evidence that ZmBT1 (Zea mays Brittle1 protein) is involved in the ADP-Glc transport into maize endosperm plastids, but up to now, no direct ADP-Glc transport mediated by ZmBT1 has ever been shown. The heterologous synth

  13. NUTRITIVE VALUE OF MAIZE (Zea Mays AND DOLECOUS (Lablab Purpureus AS AFFECTED BY PHOSPHOROUS FERTILIZATION AND INTERCROPPING

    Directory of Open Access Journals (Sweden)

    E.O. AMASAIB

    2012-11-01

    Full Text Available A field experiment was conducted at the Demonstration Farm of University of Khartoum to determine the effect of phosphorous fertilization and intercropping on the nutritive value of Zea mays and Lablab purpureus. The field experiment was arranged as Split Plot Design with four replications. The main plots were (Lablab purpureus as sole crop, Zea mays as sole crop, Lablab purpureus and Zea mays in the mixture. The sub plot treatments were phosphorous fertilization at the rate of (0, 50 and 75 kg P2O5 / ha which were then referred to as P0, P1 and P2 respectively. The plants measured were Lablab purepureus as pure stand, Lablab purepureus in the mixture, Zea mays as the pure stand and the Zea mays in the mixture. Samples of 45 days cut from sowing were used to assess the ash, crude protein (CP, ether extracts (EE, crude fiber (CF, neutral detergent fibre (NDF and dry matter digestibility. The data were statistically analyzed using complete randomized design. The results revealed that intercropping and phosphorous fertilization caused a significant (P<0.05 increased on the CP content and dry matter digestibility of all forages under estimation. Intercropping and phosphorous fertilization caused slight increase on the Ash content for all crops in this study. Moreover, Intercropping and phosphorous fertilization caused a decrease on the CF and NDF content of all forages under estimation but with no significant difference. However, Intercropping caused non–significant effect (P<0.05 on the EE content of Zea mays while, intercropping had a positive influence (P<0.05 on the EE content of Lablab purpureus. The data obtained indicated that phosphorous fertilization caused non–significant effect on the EE content of all crops in this study (P<0.05 except Lablab purpureus in the mixture with Zea mays which increased significantly (P<0.05 by increasing phosphorous level. It can be concluded that intercropping and phosphorous fertilization improved the

  14. Heterozygosity of Knob-Associated Tandem Repeats and Knob Instability in Mitotic Chromosomes of Zea (Zea mays L. and Z. diploperennis Iltis Doebley)

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yong XIONG; Yong LIU; Yong-Gang HE; Yun-Chun SONG; Ke-Xiu LI; Guan-Yuan HE

    2005-01-01

    Knobs are blocks of heterochromatin present on chromosomes of maize (Zea mays L.) and its relatives that have effects on the frequency of genetic recombination, as well as on chromosome behavior.Knob heterozygosity and instability in six maize inbred lines and one Z. diploperennis Iltis Doebley line were investigated using the fluorescence in situ hybridization (FISH) technique with knob-associated tandem repeats (180 bp and 350 bp (TR-1)) as probes. Signals of seven heterozygous knobs containing 180-bp repeats and of one heterozygous knob containing TR- 1 were captured in chromosomes of all materials tested according to the results of FISH, which demonstrates that the 180-bp repeat is the main contributor to knob heterozygosity compared with the TR-1 element. In addition, one target cell with two TR-1 signals on one homolog of chromosome 2L, which was different from the normal cells in the maize inbred line GB57,was observed, suggesting knob duplication and an instability phenomenon in the maize genome.

  15. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    Science.gov (United States)

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts.

  16. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    Science.gov (United States)

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts. PMID:26318006

  17. Acueducto pretensado sobre el Holme

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1958-04-01

    Full Text Available Breve descripción del paso de una canalización de 0,60 m de diámetro, destinada al abastecimiento de aguas, sobre el río Holme (Inglaterra. El puente formado tiene dos vigas de hormigón pretensado, cuyas armaduras se componen de barras McCall.

  18. Cross-resistance to alpha-cypermethrin after xanthotoxin ingestion in Helicoverpa zea (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Li, X; Zangerl, A R; Schuler, M A; Berenbaum, M R

    2000-02-01

    Cytochrome P450 monooxygenases (P450) are membrane-bound hemoproteins that play important roles in conferring protection against both naturally occurring phytochemicals and synthetic organic insecticides. Despite the potential for common modes of detoxification, cross-resistance between phytochemicals and synthetic organic insecticides has rarely been documented. In this study, we examined the responses of a susceptible strain of corn earworm, Helicoverpa zea (Boddie), a polyphagous noctuid, to exposure by an allelochemical infrequently encountered in its host plants and by an insecticide widely used for control purposes. Within a single generation, survivors of xanthotoxin exposure displayed higher levels of tolerance to alpha-cypermethrin than did unexposed control larvae. The F1 offspring of xanthotoxin-exposed survivors also displayed higher alpha-cypermethrin tolerance than did offspring of unexposed control larvae, suggesting that increased alpha-cypermethrin tolerance after xanthotoxin exposure represents, at least in part, heritable resistance. Administration of piperonyl butoxide, a P450 synergist, demonstrated that resistance to both xanthotoxin and alpha-cypermethrin is P450-mediated. Alpha-cypermethrin-exposed survivors, however, failed to show superior growth on xanthotoxin diets. Assays with control larvae, larvae induced by both xanthotoxin and alpha-cypermethrin, and survivors of LD50 doses of both compounds indicated that H. zea midgut P450s are capable of metabolizing both xanthotoxin and alpha-cypermethrin. Metabolism of each compound is significantly inhibited by the presence of the other compound, suggesting that at least one form of P450 in H. zea midguts degrades both compounds and may constitute the biochemical basis for possible cross-resistance. Compared with control larvae, xanthotoxin- and alpha-cypermethrin-induced larvae displayed 2- to 4-fold higher P450-mediated metabolism of both compounds. However, xanthotoxin- and alpha

  19. Sugar Mill Effluent Utilization in the Cultivation of Maize (Zea mays L. in Two Seasons

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2014-01-01

    Full Text Available The aim of present investigation is to study the effects of sugar mill effluent fertigation on soil properties and agronomical characteristics of Maize (Zea mays L. cv. NMH 589 in two seasons. Six treatments of sugar mill effluent, namely, 0% (control, 20%, 40%, 60%, 80%, and 100%, were used for the cultivation of Z. mays. Fertigation with different concentrations of sugar mill effluent resulted in significant (PZn2+>Cu2+>Cd2+>Cr3+ for soil and Mn2+>Zn2+>Cu2+>Cr3+>Cd2+ for Z. mays in both seasons after fertigation with sugar mill effluent. It appears that sugar mill effluent can be used as a biofertigant after appropriate dilution to improve the yield.

  20. FITOMEJORAMIENTO PARTICIPATIVO DEL MAÍZ ( Zea mays L.). UNA EXPERIENCIA EN LA HABANA

    OpenAIRE

    Lianne Fernández; R. Cristóbal; Ortiz, R.; N. León

    2003-01-01

    Los objetivos del trabajo fueron conocer los materiales seleccionados por los agricultores y los criterios de selección según el sexo y la localidad, así como describir y evaluar los materiales de maíz utilizados desde el punto de vista morfológico y agronómico. El trabajo se realizó en la Coo- perativa de Producción Agropecuaria “Gilberto León”, San Antonio de los Baños, provincia Habana. Se sembraron 97 entradas de maíz ( Zea mays L.), 40 procedentes de la colección de germoplasma del Insti...

  1. Genetic Analysis of the Resistance to Aspergillus flavus Infection in Maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    DENG De-xiang; JIANG Si-xia; WANG Yi-jun; BIAN Yun-long; CHEN Jian-jian; JIA Bo

    2009-01-01

    Maize (Zea mays L.),one of main crops in the world,is easily susceptible to Aspergillusflavus (Link:fr) infection,resulting huge loses worldwide.Breeding for A.flavus resistance has been proved an efficient way to solve the problem of aflatoxin contamination.Genetic analysis of the sources of resistance to A.flavus in maize is necessary for this purpose.The complete diallel crosses of 6 inbred lines with different resistance to A.flavus infection were implemented.Inoculation categorical data of each cross were analyzed with the additive-dominant and additive-dominant-epitasis genetic models.Results indicated some crosses fitted the 2 major genes with additive-dominant-epitasis genetic model.Others fitted the major gene and polygene mixed model.Moreover,the additive,dominant,and epitasis effects varied in crosses.The A.flavus resistance was controlled by both major gene and polygene.

  2. Damage potential of Heterodera zeae to Zea mays as affected by edaphic factors

    OpenAIRE

    Krusberg, L. R.; Sardanelli, S.; Grybauskas, A.P.

    1997-01-01

    On a étudié les effets du nématode à kyste du maïs, #Heterodera zeae$, sur la croissance et la récolte en grain du maïs, #Zea mays$, en microparcelles pendant les années 1986-1990. Ces expériences ont été conduites en microparcelles contenant du sol à texture fine ou grossière, avec ou sans engrais minéraux, avec ou sans #H. zeae$. La croissance du maïs (poids sec) et la récolte de grain ont décru de 13 à 73% pendant 4 ans sur 5, en présence de #H. zeae$. L'effet de #H. zeae$ sur les plantes ...

  3. QTL mapping of resistance to sheath blight in maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    YANG Hua; YANG Junpin; RONG Tingzhao; TAN Jun; QIU Zhenggao

    2005-01-01

    The genetic linkage map has been constructed with 125 SSR markers based on BC1:2 population consisting of 322 lines derived from the combination of (CML270×478) ×CML270 in maize (Zea mays L.), covering 1939.0 cM of maize genome. The average mapping distance was about 15.5 cM. Three major QTLs of the relative resistant index of resistance to maize sheath blight (Rhizoctonia solani) had been located on chromosomes 1, 7 by composite interval mapping (CIM). 7 QTLs of the plant height have been located on chromosomes 3, 4, 5, 6. Five QTLs of ear height have been located on chromosomes 3, 4, 6. The resistance to the sheath blight is shown to be not relative to plant height and ear height genetically. Inbred line CML270 was used for molecular assisted selection and cloning the genes.

  4. Purification and characterization of recombinant protein kinase CK2 from Zea mays expressed in Escherichia coli

    DEFF Research Database (Denmark)

    Riera, Marta; Pages, Montserrat; Issinger, Olaf Georg;

    2003-01-01

    Recombinant protein kinase subunits rmCK2alpha-1 and rmCK2beta-1 from Zea mays were expressed separately in Escherichia coli and assembled to a fully active tetrameric holoenzyme complex in vitro. The obtained maize holoenzyme was purified to homogeneity, biochemically characterized, and compared...... to CK2 from human. Kinetic measurements of the recombinant maize holoenzyme (rmCK2) revealed k(cat) values for ATP and GTP of 4 and 2s(-1), respectively; whereas the recombinant maize catalytic subunit showed almost equal values for ATP and GTP, i.e., ca. 0.8s(-1). A comparison of the k(cat)/K(m) ratio...

  5. Effect of gamma irradiation on the grain yield of Nigerian Zea mays and Arachis hypogaea

    International Nuclear Information System (INIS)

    As a follow-up to our earlier investigation on the effect of gamma radiation on the germination and growth of certain Nigerian agricultural crops, the present study sought to determine the effect of gamma radiation on the grain yield of Zea mays (maize) and Arachis hypogaea (groundnut). The seeds were planted after irradiation without the application of fertiliser. The results show that for maize, grain yield for irradiated samples is increased to levels above the unirradiated yield at doses up to about 250 Gy with the optimum yield occurring at 150 Gy. The corresponding increase for groundnut is observed at doses up to about 930 Gy with optimum yield at a dose of 300 Gy. Inhibition in yield was observed to set in at a dose greater than 250 Gy for maize and 930 Gy for groundnut. The actual relationship between mean yield of these crops and gamma radiation dose was obtained using sixth-degree polynomial equations. (note)

  6. Response to gravity by Zea mays seedlings. I. Time course of the response

    Science.gov (United States)

    Bandurski, R. S.; Schulze, A.; Dayanandan, P.; Kaufman, P. B.

    1984-01-01

    Gravistimulation induces an asymmetric distribution of free indole-3-acetic acid (IAA) in the cortex-epidermis of the Zea mays L. cv 'Stowells Evergreen' mesocotyl within 15 minutes, the shortest time tested. IAA was measured by an isotope dilution method as the pentaflurobenzyl ester. The per cent IAA in the lower half of the mescotyl cortex was 56 to 57% at 15, 30, and 90 minutes after stimulus initiation. Curvature is detectable in the mescotyl within 3 minutes after beginning gravitropic stimulation. The rate of curvature of the mesocotyl increases during the first 60 minutes to maximum of about 30 degrees per hour. Thus, the growth asymmetry continues to increase for 45 minutes after hormone asymmetry is established. Free IAA occurs predominantly in the stele of the mesocotyl whereas esterified IAA is mainly in the mesocotyl cortex-epidermis. This compartmentation may permit determining in which tissue the hormone asymmetry arises. Current data suggest the asymmetry originated in the stele.

  7. Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1985-01-01

    Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

  8. The effect of ethylene on root growth of Zea mays seedlings

    Science.gov (United States)

    Whalen, M. C.; Feldman, L. J.

    1988-01-01

    The control of primary root growth in Zea mays cv. Merit by ethylene was examined. At applied concentrations of ethylene equal to or greater than 0.1 microliter L-1, root elongation during 24 h was inhibited. The half-maximal response occurred at 0.6 microliter L-1 and the response saturated at 6 microliters L-1. Inhibition of elongation took place within 20 min. However, after ethylene was removed, elongation recovered to control values within 15 min. Root elongation was also inhibited by green light. The inhibition caused by a 24-h exposure to ethylene was restricted to the elongating region just behind the apex, with inhibition of cortical cell elongation being the primary contributor to the effect. Based on use of 2,5-norbornadiene, a gaseous competitive inhibitor of ethylene, it was concluded that endogenous ethylene normally inhibits root elongation.

  9. Collection of gravitropic effectors from mucilage of electrotropically-stimulated roots of Zea mays L

    Science.gov (United States)

    Fondren, W. M.; Moore, R.

    1987-01-01

    We placed agar blocks adjacent to tips of electrotropically stimulated primary roots of Zea mays. Blocks placed adjacent to the anode-side of the roots for 3 h induced significant curvature when subsequently placed asymmetrically on tips of vertically-oriented roots. Curvature was always toward the side of the root unto which the agar block was placed. Agar blocks not contacting roots and blocks placed adjacent to the cathode-side of electrotropically stimulated roots did not induce significant curvature when placed asymmetrically on tips of vertically-oriented roots. Atomic absorption spectrophotometry indicated that blocks adjacent to the anode-side of electrotropically-stimulated roots contained significantly more calcium than (1) blocks not contacting roots, and (2) blocks contacting the cathode-side of roots. These results demonstrate the presence of a gradient of endogenous Ca in mucilage of electrotropically-stimulated roots (i.e. roots undergoing gravitropic-like curvature).

  10. The influence of gravity on the formation of amyloplasts in columella cells of Zea mays L

    Science.gov (United States)

    Moore, R.; Fondren, W. M.; Koon, E. C.; Wang, C. L.

    1986-01-01

    Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, the relative volume of starch in amyloplasts in columella cells of flight-grown seedlings is significantly less than that of Earth-grown seedlings. Microgravity does not significantly alter the volume of columella cells, the average number of amyloplasts per columella cell, or the number of starch grains per amyloplast. These results are discussed relative to the influence of gravity on cellular and organellar structure.

  11. A gradient of endogenous calcium forms in mucilage of graviresponding roots of Zea mays

    Science.gov (United States)

    Moore, R.; Fondren, W. M.

    1988-01-01

    Agar blocks that contacted the upper sides of tips of horizontally-oriented roots of Zea mays contain significantly less calcium (Ca) than blocks that contacted the lower sides of such roots. This gravity-induced gradient of Ca forms prior to the onset of gravicurvature, and does not form across tips of vertically-oriented roots or roots of agravitropic mutants. These results indicate that (1) Ca can be collected from mucilage of graviresponding roots, (2) gravity induces a downward movement of endogenous Ca in mucilage overlying the root tip, (3) this gravity-induced gradient of Ca does not form across tips of agravitropic roots, and (4) formation of a Ca gradient is not a consequence of gravicurvature. These results are consistent with gravity-induced movement of Ca being a trigger for subsequent redistribution of growth effectors (e.g. auxin) that induce differential growth and gravicurvature.

  12. The involvement of glucose-6-phosphatase in mucilage secretion by root cap cells of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1985-01-01

    In order to determine the involvement of glucose-6-phosphatase in mucilage secretion by root cap cells, we have cytochemically localized the enzyme in columella and peripheral cells of root caps of Zea mays. Glucose-6-phosphatase is associated with the plasmalemma and cell wall of columella cells. As columella cells differentiate into peripheral cells and begin to produce and secrete mucilage, glucose-6-phosphatase staining intensifies and becomes associated with the mucilage and, to a lesser extent, the cell wall. Cells being sloughed from the cap are characterized by glucose-6-phosphatase staining being associated with the vacuole and plasmalemma. These changes in enzyme localization during cellular differentiation in root caps suggest that glucose-6-phosphatase is involved in the production and/or secretion of mucilage by peripheral cells of Z. mays.

  13. Endophytic Phoma sp. isolated from medicinal plants promote the growth of Zea mays

    Directory of Open Access Journals (Sweden)

    ASHWINI KEDAR

    2014-11-01

    Full Text Available Kedar A, Rathod D, Yadav A, Agarkar G, Rai M. 2014. Endophytic Phoma sp. isolated from medicinal plants promote the growth of Zea mays. Nusantara Bioscience 6: 132-139. Fungal endophytes are reported as rich sources of valuable secondary metabolites and could be used as bio-fertilizers. In the present study, we report growth promotion potential of two Phoma species isolated from Tinospora cordifolia and Calotropis procera on maize. The fungal endophytes enhanced growth in inoculated maize plants compared to non-inoculated plants. The main aim of this work was to assess the growth promotion activity of endophytic Phoma species on maize isolated from T. cordifolia and C. procera.

  14. Francisco Antonio Zea: periodista, botánico y político

    Directory of Open Access Journals (Sweden)

    Soto Arango, Diana E.

    1996-06-01

    Full Text Available This work analyzes the journalistic facet of Francisco Antonio Zea, whose first article, «Avisos de Hebephilo», was published in 1791 in the Papel Periódico de la ciudad de Santa Fé de Bogotá. His interest for the press shows at his stage of student in the National Institute of France, but won't be up to 1803, at his return to Madrid, when he proves his talent for the organization and journalistic administration on The Mercury and on the Gazette de Madrid. Later on, being manager of the Royal Botanical Garden of Madrid, he shares the management of the Semanario de Agricultura y Artes, and, finally, in 1818 establishes and directs the Venezuelan Correo del Orinoco.

    Este trabajo analiza la faceta periodística de Francisco Antonio Zea, cuyo primer artículo, «Avisos de Hebephilo», se publicó en 1791 en el Papel Periódico de la ciudad de Santa Fé de Bogota. Su interés por la prensa se manifiesta en su etapa de estudiante en el Instituto Nacional de Francia, pero no será hasta 1803, a su regreso a Madrid, cuando evidencie sus dotes para la organización y dirección periodísticas en El Mercurio y en la Gaceta de Madrid. Posteriormente, siendo director del Real Jardín Botánico de Madrid, comparte la dirección del Semanario de Agricultura y Artes, y, finalmente, en 1818 funda y dirige el venezolano Correo del Orinoco.

  15. Uptake and accumulation of copper by roots and shoots of maize(Zea may L.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of different concentrations of copper sulfate on rootand shoot growth of maize(Zea mays L.) and the uptake and accumulation of Cu2+ by its roots and shoots were investigated in the present study. The concentrations of opper sulfate (CuSO4.5H2O) used were in the range of 10-5-10-3mol/L. Root growth decreased progressively with increasing concentration of Cu2+ in solution. The seedlings exposed to 10-3 mol/L Cu exhibited substantial growth reduction, yielding only 68% of the root length of the control. The shoot growth of the seedlings grown at 10-5-10-4 mol/L Cu2+ were more or less than the same as the control seedlings. The leaves treated with 10-3 mol/L Cu2+ were obviously inhibited in shoot growth. The fresh and dry weights both in roots and shots decreased progressively with increasing Cu2+ concentration.This fits well with the above mentioned effects of copper sulfate on root growth. Zea mays has considerable ability to remove Cu from solutions and accumulate it. The Cu content in roots of Z. Mays increased with increasing solution concentration of Cu2+. The amount of Cu in roots of plants treated with 10-3, 10-4 and 10-5 mol/L Cu2+ were 10, 8 and 1.5 fold, respectively, greater than that of roots of control plant. However, the plants transported and concentrated only a small amount of Cu in their shoots.

  16. Breve informe sobre la coca

    Directory of Open Access Journals (Sweden)

    Lauro Hinostroza García

    1985-12-01

    Full Text Available El presente informe se integra en la investigación dirigida por el doctor Juan Ossio, por encargo de la Organización de los Estados Americanos (O.E.A. sobre “EFECTOS SOCIALES, CULTURALES, MÉDICOS Y ECONÓMICOS DEL USO TRADICIONAL DE LA COCA EN POBLACIONES DEL ANTIPLANO Y SIERRA DEL PERÚ, EN ESPECIAL DE LAS POBLACIONES INDÍGENAS”. Expone tópicos sobre la hoja de coca en la cultura andina: criterios clasificatorios, mitos, canciones y una muestra de qatipay o seguimiento. Este último es una práctica ritual importante para el campesinado andino, orienta el presente, pasado y futuro de toda su actividad. Cada hoja, por su forma, posición y tamaño, develará los roles sociales que ha de asumir, es decir los misterios del tiempo.

  17. Sobre la verdad en periodismo

    Directory of Open Access Journals (Sweden)

    Julio Estremadoyro Alegre

    2011-05-01

    Full Text Available Cuando un periodista informa sobre un desastre natural, con granpérdida de vidas, las autoridades y las fuentes de primera manodan cifras que son difundidas como verdades del suceso. Sinembargo, y la experiencia lo confirma, al día siguiente la cifraspueden haber cambiado y, por lo tanto, la verdad informativa esotra. Y así, sucesivamente, cada día habrá novedades y nuevas cifras verdaderas.

  18. Respons Pertumbuhan Dan Produksi Tanaman Jagung (Zea Mays. L) Terhadap Aplikasi Pupuk Organik Dari Limbah Pertanian Yang Diperkaya Dengan Bahan Peningkat Kualitas Kompos

    OpenAIRE

    Siregar, M. Rizky

    2010-01-01

    M. Rizky Siregar: growth and production of corn (Zea Mays. L) on the organic fertilizer application from agricultural waste enriched with compost quality enhancing substances, guided by HAPSOH and YAYA HASANAH. The objective of the research was to study the growth and production of corn (Zea Mays L.) on the organic fertilizer application from agricultural waste enriched with compost quality enhancing substances. The research was carried out at Research Field of Agricultural Faculty (± 25 m...

  19. Leopoldo Zea e o movimento latino-americano de História das idéias Leopoldo Zea and the Latin-American movement of History of Ideas

    Directory of Open Access Journals (Sweden)

    Eugênio Rezende de Carvalho

    2010-06-01

    Full Text Available O artigo analisa as etapas de fundação e consolidação de um dos mais importantes movimentos intelectuais da América Latina no século XX - o movimento latino-americano de História das Ideias -, a partir, sobretudo, das ações e escritos de seu principal líder e fundador, o filósofo mexicano Leopoldo Zea Aguilar (1912-2004. Na etapa de fundação, que corresponde à década de 1940, o foco principal é na obra inicial de Zea, bem como em seus primeiros esforços no sentido da articulação e organização institucional do movimento em escala continental. Já na etapa seguinte, que corresponde à década de 1950, é abordado o processo de consolidação orgânica e epistemológica do movimento.This article analyzes the stages of foundation and consolidation of one of the most important intellectual movements of Latin America in the twentieth century - the Latin-American movement of History of Ideas -, starting from actions and writings of its main leader and founder, the Mexican philosopher Leopoldo Zea Aguilar (1912-2004. In the 1940s, during the foundation period, the main focus is on the primary work of Zea, as well as on his first efforts to articulate and organize this movement in continental scale. Moreover, in the following stage held in the 1950s, the process of organic and epistemology consolidation of the movement is invoked.

  20. FERTILIZER APPLICATION METHODS AND IRRIGATION LEVELS ON EARLY (Zea mays L.) DEVELOPMENT FORMAS DE APLICAÇÃO DO FERTILIZANTE E NÍVEIS DE IRRIGAÇÃO NO DESENVOLVIMENTO DO MILHO (Zea mays)

    OpenAIRE

    Jorge Luiz do Nascimento; José Xavier de Almeida Neto

    2007-01-01

    Early corn development (Zea mays L.) was evaluated through roots (MR) and tops (MA) dry matter in a low tunnel greenhouse pot experiment, in a 2x2x4 factorial completely randomized design with three replications, comparing the fol...

  1. Inseticidas para o controle da traça-do-tomateiro e broca-grande e seu impacto sobre Trichogramma pretiosum Insecticides for the control of the South American tomato pinworm and the corn earworm and impact of those products on Trichogramma pretiosum

    Directory of Open Access Journals (Sweden)

    Marina Castelo Branco

    2003-12-01

    Full Text Available Experimentos de campo foram conduzidos entre maio e outubro de 2000 para determinar a eficiência de diversos inseticidas para o controle de Tuta absoluta e Helicoverpa zea e o impacto desses produtos sobre a emergência do parasitóide Trichogramma pretiosum. Os inseticidas testados, bem como as doses em g i.a./ha foram: metoxifenozide (120; 144, clorpirifós (540; 675, tiacloprid (72; 96 e triflumuron (144. O delineamento experimental foi de blocos ao acaso com oito tratamentos (inseticidas e testemunha e cinco repetições, com 40 plantas/parcela. Frutos de tomate foram coletados aos 58, 80 e 87 dias após o transplante das mudas para a determinação da percentagem de frutos danificados pelos insetos. O impacto dos inseticidas sobre T. pretiosum foi avaliado mediante a coleta de 20 ovos de H. zea por parcela aos 61 dias após o transplante, onde foi realizada a avaliação da emergência do parasitóide. Todos os inseticidas reduziram significativamente os danos causados por H. zea. Contudo, nenhum deles foi eficiente para o controle de T. absoluta. Metoxifenozide e clorpirifós (540 não reduziram significativamente o número de ovos parasitados por T. pretiosum quando comparados à testemunha.Field studies were conducted from May to October 2000 to determine the effectiveness of several insecticides in controlling Tuta absoluta and Helicoverpa zea and their impact on emergence of the parasitoid Trichogramma pretiosum. The insecticides tested were: methoxyfenozide (120; 144, clorpirifós (540; 675, tiacloprid (72; 96 and triflumuron (144. Application rates of all insecticides are expressed as g a.i./ha. The experiment was designed as randomized complete block with eight treatments (insecticides and untreated plots with five replications. Tomato fruits were harvested 58; 80 and 87 days after transplanting and the percentage of damaged fruits by both pests determined. The impact of insecticides on T. pretiosum survival was determined

  2. Uji Efektivitas Beberapa Waktu Aplikasi Pupuk Hijau Krinyu (Chromolaena odorata l.) Terhadap pertumbuhan dan produksi jagung (Zea mays L.)

    OpenAIRE

    Jonaha K. Purba

    2009-01-01

    Penelitian ini bertujuan untuk mengetahui keefektifitasan beberapa waktu aplikasi pupuk hijau krinyu (Chromolaena odorata L.) terhadap pertumbuhan dan produksi jagung (Zea mays L.). Penelitian dilaksanakan di desa Namo Rambe, Deli Serdang dengan ketinggian tempat sekitar 30 m di atas permukaan laut pada awal bulan Agustus hingga akhir bulan November 2008. Metode yang digunakan adalah rancangan acak kelompok (RAK) non faktorial dengan enam perlakuan dan tiga ulangan. Perlakuannya terdiri dar...

  3. Study of photosynthetic pigments changes of maize (Zea mays L.) under nano Tio2 spraying at various growth stages

    OpenAIRE

    Morteza, Elham; Payam MOAVENI; Farahani, Hossein Aliabadi; Kiyani, Mohammad

    2013-01-01

    Tests were done on the effects of treatments of titanium dioxide spray on corn (Zea mays L.). The study was conducted as a factorial experiment in a randomized complete block design with four replications. Treatments consisted of two factors; the first factor was stage of plant growth that spraying was applied (vegetative stage, appearance of male flowers and female flowers); and the second factor was that of different concentrations of titanium dioxide nanoparticles (Tio2) that consisted of ...

  4. SUITABILITY AND AVAILABILTY ANALYSES OF MARGINAL LAND FOR MAIZE (ZEA MAYS L.) PRODUCTION AND DEVELOPMENT IN SOUTH SULAWESI

    OpenAIRE

    Baja, Sumbangan; Ramlan, Andi; Amrullah, A; Muh., Ramli

    2012-01-01

    In South Sulawesi, the program for maize development (called Gong) has recently been implemented by the provincial government, as part of promoting regional food security program. In some parts of the region, cultivation of maize (Zea mays L.) has long been practiced in different soil environments including marginal land. To help address this phenomenon, there is a need for information that will allow land managers to identify both the inherent suitability of land for maize production and dev...

  5. Uji Efektifitas Beberapa Insektisida Nabati Terhadap Mortalitas Hama Sitophilus zeamais Motsch. (Coleoptera; Curculionidae) Pada Benih Jagung (Zea mays)

    OpenAIRE

    Subhan, Fadillah

    2011-01-01

    Fadillah Subhan, "Test Effectiveness of Some Insecticides Against Plant Pests Sitophilus zeamais Motsch Mortality. (Coleoptera: Curculionidae) In the Seed of Corn (Zea mays). "It was under supervised by Yuswani Pangestiningsih and Fatimah Zahara. S. zeamais is a pest of corn in storage that causes substantial yield losses, one of which effective control is the use of botanical insecticides. Testing the effectiveness of some botanical insecticides on mortality of S. zeamais on maize seed plant...

  6. Effect of soil compaction and organic matter on the early growth of maize (Zea mays) in a vertisol

    OpenAIRE

    T. Crowther; J.O. Ohu; E. Mamman

    2007-01-01

    A laboratory experiment was conducted to determine the emergence and early growth of maize (Zea mays) seeds in a dark clay soil known as vertisol (Typic Pellustert). Three quantities of groundnut haulms were incorporated into the vertisol as organic matter and then compacted at three moisture content levels using four different compactive efforts. The three organic matter and moisture content levels were 2, 4 and 6% (db), and 20, 35 and 50% (w/w), respectively. The four compactive efforts wer...

  7. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton.

    Science.gov (United States)

    Von Kanel, M B; Gore, J; Catchot, A; Cook, D; Musser, F; Caprio, M

    2016-04-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae.

  8. Wachstum und physiologisches Verhalten von Zea mays bei multiplem Streß unter besonderer Berücksichtigung des Wurzelsystems

    OpenAIRE

    Degenhardt, Birgit

    2006-01-01

    In der vorgestellten Arbeit wurden das Wachstum und das physiologische Verhalten von Zea mays auf Müllheizkraftwerk (MHKW) -Schlacke im Vergleich zu Gartenerde als Kulturmedium untersucht. Dabei stand das Wurzelsystem der Maispflanzen im Mittelpunkt des Interesses. Da feste Bodensubstrate verwendet wurden, mußten diese zu Beginn der Experimente chemisch, physikalisch und bodenbiologisch charakterisiert werden. Die Analyse der Schlacke zeigte, daß Schlacke ein multifaktorielles Streßsystem dar...

  9. PRODUCTIVITY OF INTERCROPPING MAIZE (Zea mays L.) AND PUMPKINS (Cucurbita maxima Duch.) UNDER CONVENTIONAL VS. CONSERVATION FARMING SYSTEM

    OpenAIRE

    DOLIJANOVIĆ, Željko; MOMIROVIĆ, Nebojša; OLJAČA, Snežana; SIMIĆ, Milena; OLJAČA, Mićo; JANOŠEVIĆ, Biljana

    2015-01-01

    Abstract The evaluation of pumpkin (Cucurbita maxima Duch.) and maize (Zea mays L.) intercropping productivity, under different farming systems: conventional farming vs. conservation farming was carried out on the chernozem type of soil at Zemun Polje, Serbia. Results obtained by the bivariate analysis of variance showed significant differences between different proportions of components in intercropped maize and pumpkins. Regarding the land equivalent ratio (LER), two rows of pumpkins and tw...

  10. Autoradiographic study of protein synthesis recovery in root cells of Zea mays embryos during early stages of germination

    International Nuclear Information System (INIS)

    Recovery of protein synthesis was studied in primary root of germinating Zea mays embryos. [H3] leucine or [H3] lysine was provided for two hours at 160C to embryos excised from kernels at various times after the beginning of germination. Protein synthesis (probably dependent on long-lived mRNA stocked in dormant embryo root cells) resumed during the first two hours of seed imbibition

  11. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)

    OpenAIRE

    Yu Tian; Bo Guan; Daowei Zhou; Junbao Yu; Guangdi Li; Yujie Lou

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended pri...

  12. Yields and Yield Components of Maize (Zea Mays L.) and Soybean (Glycine Max) as Affected by Different Tillage Methods

    OpenAIRE

    Kvaternjak Ivka; Kisić Ivica; Birkás Marta; Špoljar Andrija; Marenčić Dejan

    2015-01-01

    At the experiment station of the Krizevci College of Agriculture, yield and yield components of maize (Zea mays L.) and soybean (Glycine max) grown in rotation under five different methods of tillage were investigated. The aim of this study was to determine the effect of different tillage methods on yield and yield components of maize and soybean. The results and the determined number of plants per hectare of maize and soybean show that more favorable conditions for germination are in variant...

  13. Pengaruh Pemberian Beberapa Jenis Pupuk Kandang Terhadap Perkembangan Penyakit Penting Tanaman Jagung ( Zea Mays l. ) Di Lapangan

    OpenAIRE

    Maristella Simamora

    2009-01-01

    “ Pengaruh Pemberian Beberapa Jenis Pupuk Kandang Terhadap Perkembangan Penyakit Penting Pada Tanaman Jagung ( Zea mays l.) di Lapangan”. Penelitian ini dilaksanakan di lahan penelitian dan praktikum Departemen Hama dan Penyakit Tumbuhan dengan ketinggian tempat ± 25 m diatas permukaan laut. Penelitian ini menggunakan metode Rancangan Acak Kelompok (RAK) non faktorial dengan perlakuan 6 perlakuan dan 4 ulangan. Perlakuan dengan memberikan pupuk kandang yaitu : P0 = tanpa pupuk kandang, P1 = ...

  14. Cannibalism of Helicoverpa zea (Lepidoptera: Noctuidae) from Bacillus thuringiensis (Bt) transgenic corn versus non-Bt corn.

    Science.gov (United States)

    Chilcutt, Charles F

    2006-06-01

    Because of the importance of cannibalism in population regulation of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in corn, Zea mays L., it is useful to understand the interactions between Bacillus thuringiensis (Bt) transgenic corn and cannibalism. To determine the effects of Bt corn on cannibalism in H. zea, pairs of the same or different instars were taken from Bt or non-Bt corn and placed on artificial diet in proximity. Cannibalism occurred in 91% of pairs and was approximately 7% greater for pairs of larvae reared from Bt transgenic corn (95%) than from non-Bt corn (88%). Also, first instar by first instar pairs had a lower rate of cannibalism than other pairs. Time until cannibalism was not different for larvae from Bt corn versus non-Bt corn. Pupation rate of cannibals and surviving victims was not different for pairs from Bt corn versus non-Bt corn. Finally, cannibalism increased pupation rate of cannibals from both Bt and non-Bt corn by approximately 23 and 12%, respectively, although the increases were not significant. Thus, negative effects of Bt on larvae were compensated by increased cannibalism in comparison with larvae reared on non-Bt corn, which increased larval survival to levels comparable with larvae reared on non-Bt plants.

  15. Efectos en suelo y plantas debido al riego de un cultivo de maíz (Zea mays L. con el efluente de la planta de tratamiento de aguas residuales de la ciudad de Jinotepe

    Directory of Open Access Journals (Sweden)

    E. Umaña

    2006-08-01

    Full Text Available Un estudio de reúso de aguas para el riego de una parcela de cultivo de maíz (Zea mays L. se realizó en la comunidad de El Aguacate municipio de Jinotepe aprovechando los efluentes de la planta de tratamiento de aguas residuales de la ciudad de Jinotepe, con el objetivo de evaluar los efectos de esta práctica sobre las características físicas y químicas del suelo y los rendimientos obtenidos con respecto a una parcela de referencia. El manejo que se dio al cultivo fue el que tradicionalmente realizan los agricultores de la zona excepto que no se aplicó ningún fertilizante para aprovechar los nutrientes contenidos en el agua residual tratada. El monitoreo de las características del suelo se realizaron en una etapa inicial, una etapa intermedia y una etapa final del ciclo del cultivo. Los resultados obtenidos indican que estadísticamente las variaciones experimentadas en las características del suelo en la parcela de estudio no fueron significativas. Por otro lado, la calidad del efluente en cuanto al contenido de nutrientes, compensa el no uso de fertilizantes por cuanto los rendimientos obtenidos en el estudio superaron hasta en un 60 % la media de rendimientos de maíz en la zona reportados que es de 1.61 t/ha.

  16. Phytotoxicity assay of diesel fuel-spiked substrates remediated with Pleurotus tuberregium using Zea mays

    Directory of Open Access Journals (Sweden)

    E M Ogbo

    2010-06-01

    Full Text Available Summary: The remediation of soil contaminated with petroleum based compounds by white rot fungi is well documented.  In this study the ability of diesel fuel contaminated soils treated with the fungus Pleurotus tuber-regium to support plant growth was tested.  Pleurotus tuber-regium was grown in different levels (2.50, 5.00, 10.00% and control- no fungus for each level of contamination of diesel fuel contaminated soil and sawdust. The removal of petroleum hydrocarbons was highest in the 5.00% level of contamination where 55.53% of the petroleum hydrocarbons were removed. The least reduction in hydrocarbons was in the 10.00% level of contamination where only 35.53% of the hydrocarbons were removed. After the remediation the toxicity of the soils were tested by growing Zea mays in the treated soils. There was reduction in the toxicity of the soils treated with Pleurotus tuber-regium. Germination of the seeds of the test plant in treated 2.50 and 5.00% diesel fuel contaminated substrates was higher than that in the control. Germination of seeds in the 10.00% diesel fuel contaminated substrates was less than that in the control. The continued growth of the plant in the treated soils however showed no significant difference between them and the control using leaf area, plant height, fresh weight, dry weight and root length indices. The formation of lateral roots was however adversely affected in the treated 10.00% contaminated soil only substrate. The fungus was able to reduce the toxicity of diesel fuel contaminated substrates when compared with control in which there was no remediation. Industrial relevance: Nigeria is an oil producing country with heavy or high reliance on diesel fuel for use in cars and electric power generating sets. The transportation of diesel fuel is by tankers and pipelines. There have been cases of spills which has adverse effect on the environment. The study aims to solve the process of amelioration of the environment

  17. Nota sobre Keynes y Brentano

    OpenAIRE

    Crespo, Ricardo F.; IAE (Universidad Austral) y CONICET

    2013-01-01

    Este trabajo explora la posibilidad de una relación entre el pensamiento de John Maynard Keynes y el del filósofo alemán Franz Brentano (1839-1917) en los campos lógico y epistemológico. George E. Moore -profesor de Keynes- y Keynes mismo leyeron y alabaron el libro de Brentano El origen del conocimiento moral (1889). ¿Tomó Keynes algunas ideas lógicas o epistemológicas de Brentano? El trabajo sugiere que, a pesar de ciertas similitudes entre las ideas lógicas y sobre la verdad de Keynes y Br...

  18. Thomas Hobbes: sobre el miedo

    OpenAIRE

    Carlos Bührle

    2004-01-01

    Este trabajo pretende echar cierta luz sobre el papel del miedo en el pensamiento político de Hobbes. Sabido es que esta pasión subyace al contrato social, en el sentido de que impulsa al hombre a abandonar el estado de naturaleza a fin de encontrar seguridad y de deshacerse de la amenaza de la muerte violenta. Teniendo en cuenta que el miedo y la muerte son inseparables en la filosofía de Hobbes, surge una pregunta fundamental: ¿hasta qué punto podemos decir que el miedo desaparece completam...

  19. Modelos ambientales sobre la vejez

    OpenAIRE

    Izal, María; Fernández-Ballesteros, Rocío

    1990-01-01

    La perspectiva ambiental en el estudio de la vejez es probablemente un ámbito poco conocido. En este trabajo se expone una revisión crítica de los principales modelos de explicación de las relaciones ambiente-conducta en la vejez. Finalmente, se discute sobre la superación de algunas limitaciones presentes en estas formulaciones teóricas, presentándose posibles alternativas teóricas y metodológicas para el desarrollo de esta área.

  20. Historicismo: notas sobre um paradigma

    OpenAIRE

    José D’Assunção Barros

    2012-01-01

    Este artigo tem por objetivo desenvolver algumas considerações sobre o Historicismo e sua possibilidade de ser examinado como um dos paradigmas que concorrem para o estabelecimento de uma história científica no século XIX. O primeiro ponto tratado é relativo às origens do paradigma Historicista na transição do século XVIII para o século XIX. Na sequência, aproximamo-nos da apropriação conservadora do paradigma historicista no novo contexto no qual a burguesia européia está assentada no Poder,...

  1. Entorno colaborativo sobre laboratorios remotos

    OpenAIRE

    Grosclaude, Eduardo; Sznek, Jorge Eduardo; Ramos Garcia, Vicente; Bertogna, Mario Leandro; López Luro, Francisco; Zanellato, Claudio

    2006-01-01

    El proyecto de investigación Software para Procesos Colaborativos incluye una línea de acción sobre el desarrollo de experiencias en Laboratorios Remotos. Esta línea está dedicada a complementar las tareas de aprendizaje con un soporte tecnológico de sistemas, entendido como todas aquellas actividades de infraestructura que promuevan la disponibilidad de recursos y apoyen la escalabilidad de procesos en la tarea educativa apuntalada por tecnologías de información. En este trabajo se describe ...

  2. QUALITATIVE AND QUANTITATIVE EVALUATION OF POPCORN (Zea mays CULTIVARS AVALIAÇÃO DE ALGUNS ASPECTOS QUALITATIVOS E QUANTITATIVOS DE CULTIVARES DE MILHO PIPOCA (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Paulo Alcanfor Ximenes

    2007-09-01

    Full Text Available

    This study was carried out at Escola de Agronomia of’ Universidade Federal de Goiás in the  1992/93 agricultural year with the purpose of evaluating popcorn cultivars for Goiânia-GO region. The essay had 19 treatments on a randomized complete design block with 4 repetitions. The following cultivars were used as part of the Popcorn National Essay coordinated by CNPMS/EMBRAPA: H-16, CMS 42 C-I, CMS 42 C-II, CMS 43 C-I, CMS 43 C-II, UNB-2, PIRAPOCA EPAMIG, ZÉLIA-0l, SAM (STA. CECÍLIA, ROGO POP 1, ROGO POP 2, ROGO POP 3, MF 1001, MF 1002, GO 100-P, COLORADO POP 1, COLORADO POP 2, RS-20 and BR-440. It was evaluated plant height and first ear insertion height, sick plants percentage, ear index, final stand, grain/ha yield and popping expansion capacity index (E.C.. The H-16 cultivar presented the highest grain yield (2,928 kg/ha but low E.C. (11.9. The triple hybrid ZÉLIA-0l had good performance with 22.1 E.C. and l,770 kg/ha. This yield was 12% higher than the pattern cultivar SAM (STA. CECÍLIA with 1,492 kg/ha and 15.5 P.E. It was found high positive correlation among yield and female flowering date, ear index and plant and ears height. Popping expansion capacity did not present any correlation among P.E. and another studied characters.

    KEY-WORDS: Zea mays; pop-corn.

    O milho pipoca é muito consumido pela população brasileira, havendo da parte dos pesquisadores e produtores uma procura constante de cultivares mais produtivas e adequadas ao cultivo em escala comercial. Com objetivo de avaliar cultivares de milho de pipoca, conduziu-se um experimento no ano agrícola de 1992/93 na Escola de Agronomia da Universidade Federal de Goiás. O ensaio constituiu-se de

  3. Genomewide analysis of LATERAL ORGAN BOUNDARIES Domain gene family in Zea mays

    Indian Academy of Sciences (India)

    Yue-Min Zhang; Shi-Zhong Zhang; Cheng-Chao Zheng

    2014-04-01

    The investigation of transcription factor (TF) families is a major focus of postgenomic research. The plant-specific ASYMMETRIC LEAVES2-LIKE (ASL) / LATERAL ORGAN BOUNDARIES Domain (LBD) proteins constitute a major zincfinger-like-domain transcription factor family, and regulate diverse biological processes in plants. However, little is known about LBD genes in maize (Zea mays). In this study, a total of 44 LBD genes were identified in maize genome and were phylogenetically clustered into two groups (I and II), together with LBDs from Arabidopsis. The predicted maize LBDs were distributed across all the 10 chromosomes with different densities. In addition, the gene structures of maize LBDs were analysed. The expression profiles of the maize LBD genes under normal growth conditions were analysed by microarray data and qRT-PCR. The results indicated that LBDs might be involved in various aspects of physiological and developmental processes in maize. To our knowledge, this is the first report of a genomewide analysis of the maize LBD gene family, which would provide valuable information for understanding the classification and putative functions of the gene family.

  4. Protein Changes in Response to Pyrene Stress in Maize (Zea mays L.) Leaves

    Institute of Scientific and Technical Information of China (English)

    Sheng-You Xu; Ying-Xu Chen; Wei-Xiang Wu; Shao-Jian Zheng; Sheng-Guo Xue; Shi-Ying Yang; Yi-Jin Peng

    2007-01-01

    Phytoremediation is a relatively new approach to remove polycyclic aromatic hydrocarbons (PAHs) from the environment. When plants are grown under pyrene treatment, they respond by synthesizing a set of protective proteins. To learn more about protein changes in response to pyrene treatment, we extracted total proteins from the leaves of maize (Zea mays L.) 1 week after pyrene treatment. The proteins extracted were separated with twodimensional gel electrophoresis. In total, approximately 54 protein spots were found by comparing gels from treated and control groups. According to the isoelectric point, molecular weight, and abundance of these protein spots, 20 pyrene-induced proteins were found to have changed abundance. Of these, 15 protein spots were increased and five protein spots were newly appeared in pyrene-treated plant leaves. Six model upregulated protein spots of different molecular weights were excised from the gels and subjected to trypsin digestion followed by peptide separation using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Peptlde masses were used to search the matrix-science database for protein identification. Two of the proteins were identified on the basis of the homology of their peptide profiles with existing protein sequences as pyruvate orthophosphate dikinase and the rlbulose-1,5-bisphosphate carboxylase/oxygenase large subunit. These proteins are involved in the regulation of carbohydrate and energy metabolism. The present study gives new insights into the pyrene stress response in maize leaves and demonstrates the power of the proteomlc approach in phytoremediation of PAHs.

  5. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L. seedlings.

    Directory of Open Access Journals (Sweden)

    Hubert Sytykiewicz

    Full Text Available The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB in seedling leaves of the Zea mays L. Tasty Sweet (susceptible and Ambrozja (relatively resistant cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid. Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9. However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4 or 24 h (sod9 post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  6. Growth promoting characteristics of rhizobacteria and AM Fungi for biomass amelioration of Zea mays

    Directory of Open Access Journals (Sweden)

    Kumar Manoj

    2015-01-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR and mycorrhiza were evaluated on the growth (biomass and yield of Zea mays. In the present study, selective rhizospheric PGPR (Azotobacter chroococcum, Pseudomonas aeruginosa, Azospirillum brasilense and Streptomyces sp. and a combination of six strains of arbuscular mycorrhizal fungi (AMF (Acaulospora morrowae, Gigaspora margarita, Glomus constrictum, Glomus mossae, Glomus aggregatum and Scutellospora calospora were isolated and identified with standard methods and 16S rRNA sequence analysis. PGPR and AMF were checked for their growth-promoting behavior under specific treatment conditions. The 30-48-day-old treated plants in all combinations showed a significantly higher mass value. The average dry weight from the shoot was in a range from 41-52% as compared to the control. This increase also translated into a higher mass value of the roots. Overall, an 82% growth rate was observed in terms of height as the consequence of biomass production, specifically in the case of AMF + rhizobacteria combination. We report an efficient, sustainable and cost-effective biofertilizer for enhanced biomass of Z. mays, one of the staple food crops worldwide.

  7. Non-destructive leaf area measurement in maize (Zea mays L.).

    Science.gov (United States)

    Sezer, Ismail; Oner, Fatih; Mut, Zeki

    2009-09-01

    In this research, leaf area prediction model was developed for some leaf-used maize (Zea mays L.) cultivars namely Coluna, Luce, Maveric, Ranchero, TTM-813, Zamora and RX-788 grown in Black Sea region of Turkey. Lamina width, length and leaf area were measured without destroying the leaf to develop the models. The actual leaf areas of the plants were measured by PLACOM Digital Planimeter and multiple regression analysis with Excel 2003 computer package program was performed for the plants separately. The produced leaf area prediction models in the present study were formulized as LA = a - (b x W2) + [c x (W x L)] where LA is leaf area, W is leaf width, L is leaf length and a, b, c are coefficiencies. R2 values for maize cultivars tested varied with species from 0.95 in Luce to 0.98 in Maveric. All R2 values and standard errors were found to be significant at the p < 0.001 level.

  8. Responses of Different Physiological Indices for Maize (Zea mays) to Soil Water Availability

    Institute of Scientific and Technical Information of China (English)

    WU Yuan-Zhi; HUANG Ming-Bin; D. N. WARRINGTON

    2011-01-01

    Knowledge of plant responses to soil water availability is essential for the development of efficient irrigation strategies.However,notably different results have been obtained in the past on the responses of various physiological indices for different plants to soil water availability.In this study,the responses of various plant processes to soil water availability were compared with data from pot and field plot experiments conducted on maize (Zea mays L.).Consistent results were obtained between pot and field plot experiments for the responses of various relative plant indices to changes in the fraction of available soil water (FASW).A threshold value,where the relative plant indices began to decrease with soil drying,and a lower water limit,where the decline of relative plant indices changed to a very slow rate,were found.Evaporative demand not only influenced the transpiration rate over a daily scale but also determined the difference in transpirational response to soil water availability among the transient,daily and seasonal time scales.At the seasonal scale,cumulative transpiration decreased linearly with soil drying,but the decrease of transpiration from FASW =1 in response to water deficits did not affect dry weight until FASW =0.75.On the other hand,the decrease in dry weight was comparable with plant height and leaf area.Therefore,the plant responses to soil water availability were notably different among various plant indices of maize and were influenced by the weather conditions.

  9. Characterization of phenylpropanoid pathway genes within European maize (Zea mays L. inbreds

    Directory of Open Access Journals (Sweden)

    Andersen Jeppe

    2008-01-01

    Full Text Available Abstract Background Forage quality of maize is influenced by both the content and structure of lignins in the cell wall. Biosynthesis of monolignols, constituting the complex structure of lignins, is catalyzed by enzymes in the phenylpropanoid pathway. Results In the present study we have amplified partial genomic fragments of six putative phenylpropanoid pathway genes in a panel of elite European inbred lines of maize (Zea mays L. contrasting in forage quality traits. Six loci, encoding C4H, 4CL1, 4CL2, C3H, F5H, and CAD, displayed different levels of nucleotide diversity and linkage disequilibrium (LD possibly reflecting different levels of selection. Associations with forage quality traits were identified for several individual polymorphisms within the 4CL1, C3H, and F5H genomic fragments when controlling for both overall population structure and relative kinship. A 1-bp indel in 4CL1 was associated with in vitro digestibility of organic matter (IVDOM, a non-synonymous SNP in C3H was associated with IVDOM, and an intron SNP in F5H was associated with neutral detergent fiber. However, the C3H and F5H associations did not remain significant when controlling for multiple testing. Conclusion While the number of lines included in this study limit the power of the association analysis, our results imply that genetic variation for forage quality traits can be mined in phenylpropanoid pathway genes of elite breeding lines of maize.

  10. Cadmium uptake potential of Brassica napus cocropped with Brassica parachinensis and Zea mays

    International Nuclear Information System (INIS)

    Cadmium uptake potential of Brassica napus cocropped with B. parachinensis or Zea mays plants in split pot (allow the solutes to pass but prevent the interaction of roots between compartments) experiments was evaluated. Plants were grown in split pots filled with soil spiked at 0, 3, 6, 12, 25 and 50 mg Cd/kg soil. Biomass and Cd uptake were detemined after 6 weeks, and rhizospheric soil solutions, extracted using soil probes, were analyzed for pH and water soluble Cd at weekly intervals. Cadmium treatments affected the biomass. Cadmium concentration in the shoots of B. napus was higher when cocropped with B. parachinensis and significantly higher with Z. mays; however, the biomass was negatively affected implying the higher nutrient apportionment to the crop plants than B. napus. Concentration of Cd in B. napus was higher in shoots than in roots as revealed by shoot/root Cd quotient and was always >1; the quotient for B. parachinensis was ∼1 and that of Z. mays was <1, indicating the potential of Brassicaceae members to translocate the Cd to aboveground tissue. Results indicate the feasibility of cocropping method to clean the Cd contaminated soils.

  11. Computational Study on Substrate Specificity of a Novel Cysteine Protease 1 Precursor from Zea mays

    Directory of Open Access Journals (Sweden)

    Huimin Liu

    2014-06-01

    Full Text Available Cysteine protease 1 precursor from Zea mays (zmCP1 is classified as a member of the C1A family of peptidases (papain-like cysteine protease in MEROPS (the Peptidase Database. The 3D structure and substrate specificity of the zmCP1 is still unknown. This study is the first one to build the 3D structure of zmCP1 by computer-assisted homology modeling. In order to determine the substrate specificity of zmCP1, docking study is used for rapid and convenient analysis of large populations of ligand–enzyme complexes. Docking results show that zmCP1 has preference for P1 position and P2 position for Arg and a large hydrophobic residue (such as Phe. Gly147, Gly191, Cys189, and Asp190 are predicted to function as active residues at the S1 subsite, and the S2 subsite contains Leu283, Leu193, Ala259, Met194, and Ala286. SIFt results indicate that Gly144, Arg268, Trp308, and Ser311 play important roles in substrate binding. Then Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA method was used to explain the substrate specificity for P1 position of zmCp1. This study provides insights into the molecular basis of zmCP1 activity and substrate specificity.

  12. NUTRIENTS POOL IN CONSORTIA OF Eucalyptus urograndis, Acacia mearnsii AND Zea mays

    Directory of Open Access Journals (Sweden)

    Márcio Viera

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810543This study aimed to determine the nutrient pool in monospecific and mixed stands of Eucalyptus urograndis and Acacia mearnsii in a consortium with Zea mays.The amount determination of nutrients of forest species was carried out in the treatments: 100E (100% of eucalyptus; 100A (100% of black wattle and 50E:50A (50% of eucalyptus + 50% of black-wattle. On the other hand, for corn, it was carried out in all treatments (100E; 100A, 50E:50A; 75E:25A – 75% of eucalyptus + 25% black-wattle and 25E:75A – 25% of eucalyptus + 75% of black wattle. The delimitation adopted was the one of a randomized block with three replications. The magnitude of the nutrient pool in the agrossilvicultural systems biomass was: N> K > Ca > Mg > P > S, for macronutrients, and Mn > Fe > Zn > B > Cu, for micronutrients. Due to the great export of nutrients through the corn harvest, residues should be kept and it is necessary to make a nutritional reposition, mainly with P, N, K, S and Zn in the following crops, because of the higher amount that are exported with the extraction of the corn tang, which reaches 75.3; 60.6; 59.9; 55.8 e 53.8%, respectively, in relation to the total stocked in the biomass.

  13. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    Directory of Open Access Journals (Sweden)

    Mohamed Alburaki

    Full Text Available Thirty-two honeybee (Apis mellifera colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads.

  14. Exogenous melatonin improves corn (Zea mays L.) embryo proteome in seeds subjected to chilling stress.

    Science.gov (United States)

    Kołodziejczyk, Izabela; Dzitko, Katarzyna; Szewczyk, Rafał; Posmyk, Małgorzata M

    2016-04-01

    Melatonin (MEL; N-acetyl-5-methoxytryptamine) plays an important role in plant stress defense. Various plant species rich in this indoleamine have shown a higher capacity for stress tolerance. Moreover, it has great potential for plant biostimulation, is biodegradable and non-toxic for the environment. All this indicates that our concept of seed enrichment with exogenous MEL is justified. This work concerns the effects of corn (Zea mays L.) seed pre-sowing treatments supplemented with MEL. Non-treated seeds (nt), and those hydroprimed with water (H) or with MEL solutions 50 and 500 μM (HMel50, HMel500) were compared. Positive effects of seed priming are particularly apparent during germination under suboptimal conditions. The impact of MEL applied by priming on seed protein profiles during imbibition/germination at low temperature has not been investigated to date. In order to identify changes in the corn seed proteome after applying hydropriming techniques, purified protein extracts of chilling stressed seed embryos (14 days, 5°C) were separated by two-dimensional electrophoresis. Then proteome maps were graphically and statistically compared and selected protein spots were qualitatively analyzed using mass spectrometry techniques and identified. This study aimed to analyze the priming-induced changes in maize embryo proteome and at identifying priming-associated and MEL-associated proteins in maize seeds subjected to chilling. We attempt to explain how MEL expands plant capacity for stress tolerance. PMID:26945210

  15. Expression profiling of selected glutathione transferase genes in Zea mays (L. seedlings infested with cereal aphids.

    Directory of Open Access Journals (Sweden)

    Hubert Sytykiewicz

    Full Text Available The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24 in the tissues of two maize (Zea mays L. varieties (relatively resistant Ambrozja and susceptible Tasty Sweet that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L. or monophagous grain aphid (Sitobion avenae L.. Simultaneously, insect-triggered generation of superoxide anion radicals (O2•- in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23 or 24 hpi (gst1, gst18 and gst24 compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

  16. Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype. PMID:25365518

  17. Effect of salt stress on some sweet corn (Zea mays L. var. saccharata genotypes

    Directory of Open Access Journals (Sweden)

    Shtereva Lydia A.

    2015-01-01

    Full Text Available An experiment was carried out hydroponically under laboratory conditions to investigate the effect of salt stress on several physiological and biochemical parameters of three sweet corn (Zea mays L. var. saccharata genotypes: lines 6-13, C-6 (pollen source and their heterotic F1 hybrid “Zaharina”. The degree of salinity tolerance among these genotypes was evaluated at three different sodium chloride (NaCl concentrations: 0 mM, 100 mM, 125 mM and 150 mM. Seed germination, plant growth and biochemical stress determining parameters such as malondialdehyde (MDA, proline content and hydrogen peroxide (H2O2 levels were compared between seedlings of lines and hybrid. The obtained results indicated that both lines and hybrid have similar responses at different salinity levels for all examined traits. All the seedlings’ growth parameters, such as germination percentage, root length, shoot length, root and shoot fresh and dry weight, decreased with increasing salinity level. MDA, proline and H2O2 increased at different saline conditions in comparison to the control. Based on the results, of the three genotypes examined, the hybrid Zaharina, followed by line C-6, was more salt-sensitive than line 6-13 in salt stress condition.

  18. Rate of dehydration of corn (Zea mays L.) pollen in the air.

    Science.gov (United States)

    Aylor, Donald E

    2003-10-01

    The water content of corn (Zea mays L.) pollen directly affects its dispersal in the atmosphere through its effect on settling speed and viability. Therefore, the rate of water loss from pollen after being shed from the anther is an important component of a model to predict effective pollen transport distances in the atmosphere. The rate of water loss from corn pollen in air was determined using two methods: (1) by direct weighing of samples containing approximately 5 x 10(4) grains, and (2) by microscopic measurement of the change in size of individual grains. The conductance of the pollen wall to water loss was derived from the time rate of change of pollen mass or pollen grain size. The two methods gave average conductance values of 0.026 and 0.027 cm s-1, respectively. In other experiments, the water potential, psi, of corn pollen was determined at various values of relative water content (dry weight basis), either by using a thermocouple psychrometer or by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -3.218 theta(-1.35) (r2 = 0.94; for -298 pollen. The model agreed well (r2 approximately 0.98) with the observed time-course of the decrease of water content of pollen grains exposed to a range of temperature and humidity conditions. PMID:12909689

  19. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    Science.gov (United States)

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  20. Identification and characterization of the RCI2 gene family in maize (Zea mays)

    Indian Academy of Sciences (India)

    Yang Zhao; Haiqing Tong; Ronghao Cai; Xiaojian Peng; Xiaoyu Li; Defang Gan; Suwen Zhu

    2014-12-01

    Rare-cold-inducible (RCI2) genes are structurally conserved members that encode small, highly hydrophobic proteins involved in response to various abiotic stresses. Phylogenetic and functional analyses of these genes have been conducted in Arabidopsis, but an extensive investigation of the RCI2 gene family has not yet been carried out in maize. In the present study, 10 RCI2 genes were identified in a fully sequenced maize genome. Structural characterization and expression pattern analysis of 10 ZmRCI2s (Zea mays RCI2 genes) were subsequently determined. Sequence and phylogenetic analyses indicated that ZmRCI2s are highly conserved, and most of them could be grouped with their orthologues from other organisms. Chromosomal location analysis indicated that ZmRCI2s were distributed unevenly on seven chromosomes with two segmental duplication events, suggesting that maize RCI2 gene family is an evolutionarily conserved family. Putative stress-responsive cis-elements were detected in the 2-kb promoter regions of the 10 ZmRCI2s. In addition, the 10 ZmRCI2s showed different expression patterns in maize development based on transcriptome analysis. Further, microarray and quantitative real-time PCR (qRT-PCR) analysis showed that each maize RCI2 genes were responsive to drought stress, suggesting their important roles in drought stress response. The results of this work provide a basis for future cloning and application studies of maize RCI2 genes.

  1. Corn (Zea mays growth in petroleum contaminated soil, remediated with orange (Citrus sinensis peel extract

    Directory of Open Access Journals (Sweden)

    Tomás Darío Marín Veláquez

    2016-09-01

    Full Text Available Soil pollution has a strong impact when oil activity takes place within a savanna ecosystem. Any oil spill affects agricultural soils. Biostimulation with orange peel extract (Citrus sinensis is an alternative for remediation of soil contaminated with crude oil and in this research the corn plant (Zea mays was used as a biomarker of contamination level of a savanna soil after their treatment. Three samples of savannah soil contaminated with oil light crude were treated with dissolutions 1, 3 and 5% of extract of orange peel in water at a dose of 150 mL per kg of soil treated. The content of oils and fats was measured every 7 days, up to 42 days. Corn seeds were planted in soil samples, their growth was measured every 5 days for a period of 35 consecutive days, comparing their growth with seeds planted in a soil sample without contamination. According to an analysis of rank contrast, the plant growth was statistically the same in all samples up to 20 days; from there, evident differences regarding the pattern were shown.

  2. Accumulation of Hydrocarbons by Maize (Zea mays L.) in Remediation of Soils Contaminated with Crude Oil.

    Science.gov (United States)

    Liao, Changjun; Xu, Wending; Lu, Guining; Liang, Xujun; Guo, Chuling; Yang, Chen; Dang, Zhi

    2015-01-01

    This study has investigated the use of screened maize for remediation of soil contaminated with crude oil. Pots experiment was carried out for 60 days by transplanting maize seedlings into spiked soils. The results showed that certain amount of crude oil in soil (≤2 147 mg·kg(-1)) could enhance the production of shoot biomass of maize. Higher concentration (6 373 mg·kg(-1)) did not significantly inhibit the growth of plant maize (including shoot and root). Analysis of plant shoot by GC-MS showed that low molecular weight polycyclic aromatic hydrocarbons (PAHs) were detected in maize tissues, but PAHs concentration in the plant did not increase with higher concentration of crude oil in soil. The reduction of total petroleum hydrocarbon in planted soil was up to 52.21-72.84%, while that of the corresponding controls was only 25.85-34.22% in two months. In addition, data from physiological and biochemical indexes demonstrated a favorable adaptability of maize to crude oil pollution stress. This study suggested that the use of maize (Zea mays L.) was a good choice for remediation of soil contaminated with petroleum within a certain range of concentrations.

  3. Compositional equivalency of Cry1F corn event TC6275 and conventional corn (Zea mays L.).

    Science.gov (United States)

    Herman, Rod A; Phillips, Amy M; Collins, Randy A; Tagliani, Laura A; Claussen, Fred A; Graham, Christopher D; Bickers, Brenda L; Harris, Travis A; Prochaska, Lee M

    2004-05-01

    Maize (Zea mays L.) plants have been transformed to express a Cry1F insecticidal crystal protein originally isolated from Bacillus thuringiensis Berliner. This protein controls lepidopteran pests of maize, including the European corn borer, Ostrinia nubilalis (Hübner). As part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. This analysis is designed to detect unintended changes in the nutrient and antinutrient content of the raw commodities produced by the crop due to the insertion of the genes into the genomic DNA of the plant (pleotropic effects). Samples of transgenic and nontransgenic maize forage and grain were collected from six field sites located in the U.S. and Canada. Forage samples were analyzed for proximates and minerals, and grain was further analyzed for fatty acids, amino acids, vitamins, secondary metabolites, and antinutrients. Results demonstrated that maize expressing the Cry1F protein was equivalent to nontransgenic maize with respect to these important components. Comparison of the variability within the nontransgenic and transgenic hybrid, as compared to composition values reported in the literature, suggest that factors other than transgenes may contribute more substantially to the composition of crops.

  4. Root cap removal increases root penetration resistance in maize (Zea mays L).

    Science.gov (United States)

    Iijima, Morio; Higuchi, Toshifumi; Barlow, Peter W; Bengough, A Glyn

    2003-09-01

    The root cap assists the passage of the root through soil by means of its slimy mucilage secretion and by the sloughing of its outer cells. The root penetration resistance of decapped primary roots of maize (Zea mays L. cv. Mephisto) was compared with that of intact roots in loose (dry bulk density 1.0 g cm-3; penetration resistance 0.06 MPa) and compact soil (1.4 g cm-3; penetration resistance 1.0 MPa), to evaluate the contribution of the cap to decreasing the impedance to root growth. Root elongation rate and diameter were the same for decapped and intact roots when the plants were grown in loose soil. In compacted soil, however, the elongation rate of decapped roots was only about half that of intact roots, whilst the diameter was 30% larger. Root penetration resistances of intact and decapped seminal axis were 0.31 and 0.52 MPa, respectively, when the roots were grown in compacted soil. These results indicated that the presence of a root cap alleviates much of the mechanical impedance to root penetration, and enables roots to grow faster in compacted soils.

  5. Overexpression of Arabidopsis molybdenum cofactor sulfurase gene confers drought tolerance in maize (Zea mays L..

    Directory of Open Access Journals (Sweden)

    Yao Lu

    Full Text Available Abscisic acid (ABA is a key component of the signaling system that integrates plant adaptive responses to abiotic stress. Overexpression of Arabidopsis molybdenum cofactor sulfurase gene (LOS5 in maize markedly enhanced the expression of ZmAO and aldehyde oxidase (AO activity, leading to ABA accumulation and increased drought tolerance. Transgenic maize (Zea mays L. exhibited the expected reductions in stomatal aperture, which led to decreased water loss and maintenance of higher relative water content (RWC and leaf water potential. Also, transgenic maize subjected to drought treatment exhibited lower leaf wilting, electrolyte leakage, malondialdehyde (MDA and H(2O(2 content, and higher activities of antioxidative enzymes and proline content compared to wild-type (WT maize. Moreover, overexpression of LOS5 enhanced the expression of stress-regulated genes such as Rad 17, NCED1, CAT1, and ZmP5CS1 under drought stress conditions, and increased root system development and biomass yield after re-watering. The increased drought tolerance in transgenic plants was associated with ABA accumulation via activated AO and expression of stress-related gene via ABA induction, which sequentially induced a set of favorable stress-related physiological and biochemical responses.

  6. Cytogenetics of monosomes in Zea mays. Progress report, May 16, 1979-May 15, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D. F.

    1980-02-01

    Monosomics lack a pairing partner in each meiotic cell, and genes on an entire chromosome are present in the hemizygous condition. Monosomics for chromosomes 1, 2, 3, 4, 6, 7, 8, 9, and 10 in Zea mays have been isolated. This is the only series of this type that has been recovered in any diploid organism. The monosomic plants are vigorous, good cytological samples can be taken, and crosses can be made. All possible monosomic types are being isolated and characterized by studying: (1) the cytology of meiosis; (2) the cytological behavior of univalent chromosomes; (3) the effect of monosomy and trisomy on intergenic and intragenic recombination; (4) the frequency and types of spontaneous chromosomal aberrations arising in monosomics; (5) the effect of aneuploidy on the relative amounts of specific fatty acids in embryos; (6) monosomic mutational mapping; and (7) metabolic profile analysis of monosomics. Systems in maize to detect the environmental and genetic induction of non-disjunction are also being developed. By comparing a monosomic with its disomic siblings, one compares one and two copies of all genes on an entire chromosome. If a gene expressing dosage effects resides on a specific chromosome, a difference will be found between a plant monosomic for that chromosome and its diploid siblings. Genetic factors that control the meiotic process, genetic recombination, lipid biosynthesis, and the free amino acid pool have been discovered.

  7. Cytogenetics of monosomes in Zea mays. Progress report, May 16, 1980-May 15, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D. F.

    1981-02-01

    Monosomics lack a pairing partner in each meiotic cell, and genes on an entire chromosome are present in the hemizygous condition. We have isolated monosomics for chromosomes 1, 2, 3, 4, 6, 7, 8, 9, and 10 in Zea mays utilizing a recently-discovered system. This is the only series of this type that has been recovered in any diploid organism. The monosomic plants are surprisingly vigorous, good cytological samples can be taken, and crosses can be made. We are isolating all possible monosomic types and characterizing them by studying: (1) the cytology of meiosis, (2) the cytological behavior of univalent chromosomes, (3) the effect of monosomy and trisomy on intergenic and intragenic recombination, (4) the frequency and types of spontaneous chromosomal aberrations arising in monosomics, (5) the effect of aneuploidy on the relative amounts of specific fatty acids in embryos, (6) monosomic mutational mapping, (7) the effect of monosomy on pollen exine morphology with the scanning electron microscope, and (8) the effect of monosomy on DIMBOA levels. We are also developing test systems utilizing maize to detect the environmental or genetic induction of non-disjunction. This study has discovered genetic factors that control the meiotic process, genetic recombination, lipid biosynthesis, and the free amino acid pool.

  8. Preliminary assessment of risk of ozone impacts to maize (Zea mays) in southern Africa

    International Nuclear Information System (INIS)

    Surface ozone concentrations in southern Africa exceed air quality guidelines set to protect agricultural crops. This paper addresses a knowledge gap by performing a preliminary assessment of potential ozone impacts on vegetation in southern African. Maize (Zea mays L.) is the receptor of interest in the main maize producing countries, i.e. South Africa, Zambia and Zimbabwe. Surface ozone concentrations are estimated for the growing season (October to April) using photochemical modelling. Hourly mean modelled ozone concentrations ranged between 19.7 and 31.2 ppb, while maximums range between 28.9 and 61.9 ppb, and are near 30 ppb over South Africa and Zambia, while in Zimbabwe, they exceed 40 ppb and translate into monthly AOT40 values of over 3000 ppb h in five of the seven months of the growing season. This study suggests that surface ozone may pose a threat to agricultural production in southern African, particularly in Zimbabwe. - Ozone impacts on crops in southern Africa are assessed using current European-based methods (AOT40 concept)

  9. Influence of Corn (Zea mays L. Cultivar Development on Grain Nutrient Concentration

    Directory of Open Access Journals (Sweden)

    Carla Fernanda Ferreira

    2012-01-01

    Full Text Available While corn productivity has been increased by the adoption of high-yield hybrids, there are concerns that increased grain potential may be associated with diminished grain nutrient concentration. Ten corn (Zea mays L. cultivars representing five technological levels (landrace variety, commercial variety, and double, triple, and single cross-hybrids were cropped on a Rhodic Ferralsol Eutric soil with high fertility in 2006 (dry year and 2007 (normal year in Rolândia County, Brazil. At maturity, grain was evaluated for concentrations of P, K, Ca, Mg, Fe, Mn, Zn, and Cu. In general, differences among cultivars were noted for all nutrients in both years. Concentrations of P, K, Fe, and Mn were lower in the dry year, while Ca, Mg, Cu, and Zn were higher. Soil water availability appeared to exert more influence on grain nutrient concentration than did cultivar development; nutrient removal due to grain harvest was also greatly influenced by rainfall patterns and their impact on corn productivity. Even though genetic differences were noted, which may be useful to breeding programs, long-term testing in subtropical environments will be required to clarify the interaction between genetics and climate events on grain nutrient quality and exportation.

  10. Detection of Cell Wall Chemical Variation in Zea Mays Mutants Using Near-Infrared Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Buyck, N.; Thomas, S.

    2001-01-01

    Corn stover is regarded as the prime candidate feedstock material for commercial biomass conversion in the United States. Variations in chemical composition of Zea mays cell walls can affect biomass conversion process yields and economics. Mutant lines were constructed by activating a Mu transposon system. The cell wall chemical composition of 48 mutant families was characterized using near-infrared (NIR) spectroscopy. NIR data were analyzed using a multivariate statistical analysis technique called Principal Component Analysis (PCA). PCA of the NIR data from 349 maize leaf samples reveals 57 individuals as outliers on one or more of six Principal Components (PCs) at the 95% confidence interval. Of these, 19 individuals from 16 families are outliers on either PC3 (9% of the variation) or PC6 (1% of the variation), the two PCs that contain information about cell wall polymers. Those individuals for which altered cell wall chemistry is confirmed with wet chemical analysis will then be subjected to fermentation analysis to determine whether or not biomass conversion process kinetics, yields and/or economics are significantly affected. Those mutants that provide indications for a decrease in process cost will be pursued further to identify the gene(s) responsible for the observed changes in cell wall composition and associated changes in process economics. These genes will eventually be incorporated into maize breeding programs directed at the development of a truly dual use crop.

  11. Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

    Science.gov (United States)

    Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

    2012-01-01

    Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

  12. Biochemical and Photosynthetic Evaluation of Responses in Zea mays L. Under Drought Stress

    Directory of Open Access Journals (Sweden)

    S. S. Abu-Muriefah

    2014-04-01

    Full Text Available Antioxidant defense system(s, pigments content and photosynthetic activity as well as some biochemical changes under drought stress were analyzed in maize (Zea mays L. cv. Giza 21 leaves to determine the response of plant to drought stress and to elucidate the role of various protective mechanisms against oxidative stress. It was found that the application of drought stress led to changes in the carbohydrates and protein contents. Total soluble sugars, accumulated in the leavesof water-stressed plants, whereas, starch and protein contents were dropped to a small amounts compared to the control. Furthermore, plants have well-developed defense systems againstreactive oxygen species (ROS, involving both limiting the formation of ROS as well asinstituting its removal. Within a cell, the activities of a range of antioxidant enzymes suchas superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase(APX involved in scavenging ROS were investigated. During dehydrationthe SOD, APX and CAT increased significantly up to 4 days, then declined in their activities but still maintained higher than the control levels this indicates that the defense systems involvedare efficient in the protection of plant cells against oxidation. In addition, there was consistent increase in the lipid peroxidation and accumulation of malondialdehyde (MDA. The levels of hydrogen peroxide were also elevated during stressing periods. In this study we are reporting the negative response of maize plants toward drought stress especially on the antioxidant enzymatic activity for the prolonged drought effect.

  13. The effect of bottom sediment supplement on heavy metals content in plants (Zea mays and soil

    Directory of Open Access Journals (Sweden)

    Baran A.

    2013-04-01

    Full Text Available Important aspect of bottom sediments is the problem of their management or disposal after their extraction from the bottom of rivers, dam reservoirs, ports, channels or ponds. The research aimed at an assessment of potential environmental management of bottom sediment used as an admixture to light soil basing on its effect on contents of heavy metals in plants and soil. The research was conducted on light soil with granulometric structure of weakly loamy sand. The bottom sediment was added to light soil in the amount of 0 (control 5, 10, 30 i 50%. The test plant was maize (Zea mays, “Bora” c.v. The sediment applied in the presented research revealed high share of silt and clay fractions, alkaline pH and low contents of heavy metals, therefore it may be used as an admixture to the above mentioned soils to improve their productivity. The applied bottom sediment to the soil affected a decreased in Zn, Cd and Pb content in maize in comparison with the treatment without the deposit whereas increased content of Cu, Cr and Ni. No exceeded permissible content of heavy metals concerning plant assessment in view of their forage usability were registered in maize biomass.

  14. Perennial aneuploidy as a potential material for gene introgression between maize and Zea perennis

    Institute of Scientific and Technical Information of China (English)

    FU Jie; TANG Qi-lin; YANG Xiu-yan; CHENG Ming-jun; LÜ Gui-hua; WANG Pei; WU Yuan-qi; ZHENG Ming-min; ZHOU Shu-feng; RONG Ting-zhao

    2015-01-01

    Hybridization, which al ows for gene lfow between crops, is dififcult between maize and Zea perennis. In this study, we aim to initiate and study gene lfow between maize and Z. perennis via a special aneuploid plant (MDT) derived from an interspeciifc hybrid of the two species. The chromosome constitution and morphological characters of MDT as wel as certain backcross progenies were examined. Results from genomic in situ hybridization (GISH) indicate that aneuploid MDT consisted of nine maize chromosomes and 30 Z. perennis chromosomes. The backcross progenies of MDT×maize displayed signiifcant diversity of vegetative and ear morphology;several unusual plants with speciifc chromosome constitution were founded in its progenies. Some special perennial progeny with several maize chromosomes were obtained by backcrossing MDT with Z. perennis, and the ifrst whole chromosome introgression from maize to Z. perennis was detected in this study. With this novel material and method, a number of maize-tetraploid teosinte addition or substitution lines can be generated for further study, which has great signiifcance to maize and Z. perennis genetic research, especial y for promoting introgression and transferring desirable traits.

  15. Response of maize (Zea mays L. saccharata Sturt) to different concentration treatments of deltamethrin.

    Science.gov (United States)

    Duran, Ragbet Ezgi; Kilic, Semra; Coskun, Yasemin

    2015-10-01

    The aim of this study was to investigate the effect of the deltamethrin pesticide on the biological properties of maize (Zea mays L. saccharata Sturt). Maize seeds were exposed to environmentally relevant dosages (0.01, 0.05, 0.1 and 0.5 ppm) of deltamethrin. On the 7th day of germination, morphological, anatomical and physiological responses were determined. All seedling growth characters were decreased with increasing deltamethrin levels. The most negative effect on the radicle length of maize was observed by the highest deltamethrin concentration with a 61% decrease (P <0.05). Both stomatal density and stomatal dimension reduction were caused by increasing concentrations of deltamethrin. Moreover, the pigments like chlorophyll a, chlorophyll b, total chlorophyll and caretonoids decreased with the increase in deltamethrin concentration. Conversely, anthocyanin and proline content increased in parallel with deltamethrin concentration. As a result, all morphological traits and pigments except for proline and anthocyanin were significantly reduced with an increase in pesticide concentration, compared to control (P <0.05). PMID:26453225

  16. Cytochemical localization of calcium in cap cells of primary roots of Zea mays L

    Science.gov (United States)

    Moore, R.

    1986-01-01

    The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.

  17. Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

    Science.gov (United States)

    Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

    1988-01-01

    Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

  18. Calcium-regulated in vivo protein phosphorylation in Zea mays L. root tips

    Science.gov (United States)

    Raghothama, K. G.; Reddy, A. S.; Friedmann, M.; Poovaiah, B. W.

    1987-01-01

    Calcium dependent protein phosphorylation was studied in corn (Zea mays L.) root tips. Prior to in vivo protein phosphorylation experiments, the effect of calcium, ethyleneglycol-bis-(beta-aminoethyl ether)-N-N' -tetraacetic acid (EGTA) and calcium ionophore (A-23187) on phosphorus uptake was studied. Calcium increased phosphorus uptake, whereas EGTA and A-23187 decreased it. Consequently, phosphorus concentration in the media was adjusted so as to attain similar uptake in different treatments. Phosphoproteins were analyzed by two-dimensional gel electrophoresis. Distinct changes in phosphorylation were observed following altered calcium levels. Calcium depletion in root tips with EGTA and A-23187 decreased protein phosphorylation. However, replenishment of calcium following EGTA and ionophore pretreatment enhanced phosphorylation of proteins. Preloading of the root tips with 32P in the presence of EGTA and A-23187 followed by a ten minute calcium treatment, resulted in increased phosphorylation indicating the involvement of calcium, calcium and calmodulin-dependent kinases. Calmodulin antagonist W-7 was effective in inhibiting calcium-promoted phosphorylation. These studies suggest a physiological role for calcium-dependent phosphorylation in calcium-mediated processes in plants.

  19. Depth Profiles in Maize ( Zea mays L.) Seeds Studied by Photoacoustic Spectroscopy

    Science.gov (United States)

    Hernández-Aguilar, C.; Domínguez-Pacheco, A.; Cruz-Orea, A.; Zepeda-Bautista, R.

    2015-06-01

    Photoacoustic spectroscopy (PAS) has been used to analyze agricultural seeds and can be applied to the study of seed depth profiles of these complex samples composed of different structures. The sample depth profile can be obtained through the photoacoustic (PA) signal, amplitude, and phase at different light modulation frequencies. The PA signal phase is more sensitive to changes of thermal properties in layered samples than the PA signal amplitude. Hence, the PA signal phase can also be used to characterize layers at different depths. Thus, the objective of the present study was to obtain the optical absorption spectra of maize seeds ( Zea mays L.) by means of PAS at different light modulation frequencies (17 Hz, 30 Hz, and 50 Hz) and comparing these spectra with the ones obtained from the phase-resolved method in order to separate the optical absorption spectra of seed pericarp and endosperm. The results suggest the possibility of using the phase-resolved method to obtain optical absorption spectra of different seed structures, at different depths, without damaging the seed. Thus, PAS could be a nondestructive method for characterization of agricultural seeds and thus improve quality control in the food industry.

  20. Comparative effectiveness of metal ions in inducing curvature of primary roots of Zea mays

    Science.gov (United States)

    Hasenstein, K. H.; Evans, M. L.; Stinemetz, C. L.; Moore, R.; Fondren, W. M.; Koon, E. C.; Higby, M. A.; Smucker, A. J.

    1988-01-01

    We used five cultivars of Zea mays (Bear Hybrid WF9 * 38MS, B73 * Missouri 17, Yellow Dent, Merit, and Great Lakes Hybrid 422) to reinvestigate the specificity of metal ions for inducing root curvature. Of 17 cations tested, 6 (Al3+, Ba2+, Ca2+, Cd2+, Cu2+, Zn2+) induced curvature. Roots curved away from Al3+, Ba2+, and Cd2+. Roots curved away from low (0.1 millimolar) concentrations of Cu2+ but toward higher (1-5 millimolar) concentrations. Roots initially curved away from Zn2+ but the direction of the subsequent curvature was unpredictable. In most cases, roots of all cultivars curved towards calcium. However, in some tests there was no response to calcium or even (especially in the cultivars Merit and B73 * Missouri 17) substantial curvature away from calcium. The results indicate that the induction of root curvature is not specific for calcium. The results are discussed relative to the possible role of calmodulin as a mediator of ion-induced root curvature.

  1. Plant species coexistence alleviates the impacts of lead on Zea mays L.

    Institute of Scientific and Technical Information of China (English)

    Ruyi Yang; Ling Liu; Shuting Zan; Jianjun Tang; Xin Chen

    2012-01-01

    Whether plant coexistence can reduce the impacts of lead(Pb)on crops in agroecosystems has not been well understood.We conducted a factorial experiment to investigate the effects of weeds coexisting with maize(Zea mays L.)on Pb accumulation in maize and soil microbes at two Pb levels(ambient and 300 mg/kg).Elevated Pb tended to increase the Pb concentration in maize and decreased soil microbial activity(indicated by the average well color development,AWCD),functional group diversity,as well as arbuscular mycorrhizal(AM)colonization and vesicle number of maize.Compared to the monoculture,weeds coexisting with maize reduced the Pb concentrations in the root,leaf,sheath and stem of maize at both seedling and mature stages.In maize-weed mixtures,soil microbial activity and functional group diversity tended to increase for both Pb treatments relative to the monoculture.Furthermore,principal component analysis revealed that the soil microbial community structure changed with the introduction of weeds.The highest Pb accumulation in weeds occurred for the elevated Pb treatment in a three species mixture.The results suggest that multiple plant species coexistence could reduce lead accumulation in crop plants and alleviate the negative impacts on soil microbes in polluted land,thereby highlighting the significance of plant diversity in agroecosystems.

  2. Morphometric analysis of epidermal differentiation in primary roots of Zea mays

    Science.gov (United States)

    Moore, R.; Smith, H. S.

    1990-01-01

    Epidermal differentiation in primary roots of Zea mays was divided into six cell types based on cellular shape and cytoplasmic appearance. These six cell types are: 1) apical protoderm, located at the tip of the root pole and characterized by periclinally flattened cells; 2) cuboidal protoderm, located approximately 230 microns from the root pole and characterized by cuboidal cells; 3) tabular epidermis, located approximately 450 microns from the root pole and characterized by anticlinally flattened cells; 4) cuboidal epidermis, located approximately 900 microns from the root pole and characterized by cuboidal cells having numerous small vacuoles; 5) vacuolate cuboidal epidermis, located approximately 1,500 microns from the root pole and characterized by cuboidal cells containing several large vacuoles; and 6) columnar epidermis, located approximately 2,200 microns from the root pole (i.e., at the beginning of the zone of elongation) and characterized by elongated cells. We also used stereology to quantify the cellular changes associated with epidermal differentiation. The quiescent center and the apical protoderm have significantly different ultrastructures. The relative volume of dictyosomes increases dramatically during the early stages of epidermal differentiation. This increase correlates inversely with the amount of coverage provided by the root cap and mucilage.

  3. Effect of a longitudinally applied voltage upon the growth of Zea mays seedlings

    Science.gov (United States)

    Desrosiers, M. F.; Bandurski, R. S.

    1988-01-01

    The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays L. (cv Silver Queen) seedlings for periods of 3 or 4 hours. It was determined that: (a) making the tips of the seedlings electrically positive relative to the base strongly inhibited shoot growth at 5 volts, whereas the reverse polarity had no effect; (b) at higher voltages, making the tip of the seedlings negative caused less growth inhibition than the reverse polarity at each voltage level; (c) the higher the applied voltage the greater the degree of inhibition; and, (d) the more growth inhibition experienced by the plants the poorer, and slower, their recovery. Previous observations of a relationship between the amount of free indole-3-acetic acid in the mesocotyl cortex and the growth rate of the mesocotyl and of gravitropism-induced movement of labeled indole-3-acetic acid from the seed to the shoot lead to the prediction of a voltage-dependent gating of the movement of indole-3-acetic acid from the stele to the cortex. This provided the basis for attempting to alter the growth rate of seedlings by means of an applied voltage.

  4. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials

    Science.gov (United States)

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  5. Open Field Study of Some Zea mays Hybrids, Lipid Compounds and Fumonisins Accumulation

    Directory of Open Access Journals (Sweden)

    Paola Giorni

    2015-09-01

    Full Text Available Lipid molecules are increasingly recognized as signals exchanged by organisms interacting in pathogenic and/or symbiotic ways. Some classes of lipids actively determine the fate of the interactions. Host cuticle/cell wall/membrane components such as sphingolipids and oxylipins may contribute to determining the fate of host–pathogen interactions. In the present field study, we considered the relationship between specific sphingolipids and oxylipins of different hybrids of Zea mays and fumonisin by F. verticillioides, sampling ears at different growth stages from early dough to fully ripe. The amount of total and free fumonisin differed significantly between hybrids and increased significantly with maize ripening. Oxylipins and phytoceramides changed significantly within the hybrids and decreased with kernel maturation, starting from physiological maturity. Although the correlation between fumonisin accumulation and plant lipid profile is certain, the data collected so far cannot define a cause-effect relationship but open up new perspectives. Therefore, the question—“Does fumonisin alter plant lipidome or does plant lipidome modulate fumonisin accumulation?”—is still open.

  6. Evolution of Resistance by Helicoverpa zea (Lepidoptera: Noctuidae) Infesting Insecticidal Crops in the Southern United States.

    Science.gov (United States)

    Pan, Zaiqi; Onstad, David; Crain, Philip; Crespo, Andre; Hutchison, William; Buntin, David; Porter, Pat; Catchot, Angus; Cook, Don; Pilcher, Clint; Flexner, Lindsey; Higgins, Laura

    2016-04-01

    We created a deterministic, frequency-based model of the evolution of resistance by corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), to insecticidal traits expressed in crops planted in the heterogeneous landscapes of the southern United States. The model accounts for four generations of selection by insecticidal traits each year. We used the model results to investigate the influence of three factors on insect resistance management (IRM): 1) how does adding a third insecticidal trait to both corn and cotton affect durability of the products, 2) how does unstructured corn refuge influence IRM, and 3) how do block refuges (50% compliance) and blended refuges compare with regard to IRM? When Bt cotton expresses the same number of insecticidal traits, Bt corn with three insecticidal traits provides longer durability than Bt corn with two pyramided traits. Blended refuge provides similar durability for corn products compared with the same level of required block refuge when the rate of refuge compliance by farmers is 50%. Results for Mississippi and Texas are similar, but durabilities for corn traits are surprisingly lower in Georgia, where unstructured corn refuge is the highest of the three states, but refuge for Bt cotton is the lowest of the three states. Thus, unstructured corn refuge can be valuable for IRM but its influence is determined by selection for resistance by Bt cotton. PMID:26637533

  7. Characteristics and functional properties of purple corn (Zea mays L. var. subnigroviolaceo

    Directory of Open Access Journals (Sweden)

    Jhoseline Guillén-Sánchez

    2014-09-01

    Full Text Available Zea Mays L. variety purple (purple corn is a plant native of America, which has the episperm seeds (grains and the cobs (cob in purple, which gives special characteristics to the pigments that have (between 1.5% and 6.0%, called anthocyanins, which belong to the group of flavonoids. Due to its high content of anthocyanins (cianin C3G-3-glucose as its main color and phenolic compounds act as powerful natural antioxidant and anticancer, Further having functional properties due to these bioactive compounds. The purple corn also provides significant amounts of starch, about 80% (complex carbohydrate, 10% of sugars provide sweetness, up to 11% protein, up to 2% minerals and B vitamins and ascorbic acid, concentrated in endosperm (grain free envelope. Also the nutritional value, the purple corn has a rich composition of phytochemicals, which have beneficial effects on our body, such as neutralize free radicals and act as antimutagenic. His review paper aimed to collect information on the studies undertaken to purple corn as an alternative to artificial food dyes and health benefits when included in the diet. Benefits such as cardiovascular diseases (hypertension, lowering cholesterol, fighting diabetes, being the most remarkable antioxidant action (wrinkle.

  8. Targeted mutagenesis in Zea mays using TALENs and the CRISPR/Cas system.

    Science.gov (United States)

    Liang, Zhen; Zhang, Kang; Chen, Kunling; Gao, Caixia

    2014-02-20

    Transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems have emerged as powerful tools for genome editing in a variety of species. Here, we report, for the first time, targeted mutagenesis in Zea mays using TALENs and the CRISPR/Cas system. We designed five TALENs targeting 4 genes, namely ZmPDS, ZmIPK1A, ZmIPK, ZmMRP4, and obtained targeting efficiencies of up to 23.1% in protoplasts, and about 13.3% to 39.1% of the transgenic plants were somatic mutations. Also, we constructed two gRNAs targeting the ZmIPK gene in maize protoplasts, at frequencies of 16.4% and 19.1%, respectively. In addition, the CRISPR/Cas system induced targeted mutations in Z. mays protoplasts with efficiencies (13.1%) similar to those obtained with TALENs (9.1%). Our results show that both TALENs and the CRISPR/Cas system can be used for genome modification in maize.

  9. Climate Change Adaptation: Real Time Nitrogen Management in Maize (Zea Mays L. Using Leaf Colour Chart

    Directory of Open Access Journals (Sweden)

    R. K. Mathukia

    2014-12-01

    Full Text Available A field experiment was conducted at Instructional Farm, College of Agriculture, Junagadh Agricultural University, Junagadh during rabi 2011-12 and 2012-13 to study the real time nitrogen management using leaf colour chart (LCC in maize (Zea mays L.. Basal dose of 20-50 kg N-P2O5/ha was applied in all the treatments. Top dressing of 60 or 80 N in form of Urea in two splits at LCC 2, 3, 4 and 5 were compared with fixed time N application [50 kg N/ha at 30 DAS + 30 kg N/ha at 60 days after sowing (DAS]. Top dressing of 50 kg N/ha + 30 kg N/ha when LCC=4 or LCC=5 significantly improved growth and yield attributes viz., plant height, dry matter accumulation/plant, number of leaves/plant, stem diameter, number of internodes/ plant, leaf area index, cob length, cob girth, number of cobs/plant, number of grains/cob, grain weight/plant and 1000-grain weight along with higher grain and stover yields, grain protein content and economic returns over fixed time application of 50 kg N/ha at 30 DAS + 30 kg N/ha at 60 DAS.

  10. Quantitative trait loci for mercury accumulation in maize (Zea mays L. identified using a RIL population.

    Directory of Open Access Journals (Sweden)

    Zhongjun Fu

    Full Text Available To investigate the genetic mechanism of mercury accumulation in maize (Zea mays L., a population of 194 recombinant inbred lines derived from an elite hybrid Yuyu 22, was used to identify quantitative trait loci (QTLs for mercury accumulation at two locations. The results showed that the average Hg concentration in the different tissues of maize followed the order: leaves > bracts > stems > axis > kernels. Twenty-three QTLs for mercury accumulation in five tissues were detected on chromosomes 1, 4, 7, 8, 9 and 10, which explained 6.44% to 26.60% of the phenotype variance. The QTLs included five QTLs for Hg concentration in kernels, three QTLs for Hg concentration in the axis, six QTLs for Hg concentration in stems, four QTLs for Hg concentration in bracts and five QTLs for Hg concentration in leaves. Interestingly, three QTLs, qKHC9a, qKHC9b, and qBHC9 were in linkage with two QTLs for drought tolerance. In addition, qLHC1 was in linkage with two QTLs for arsenic accumulation. The study demonstrated the concentration of Hg in Hg-contaminated paddy soil could be reduced, and maize production maintained simultaneously by selecting and breeding maize Hg pollution-safe cultivars (PSCs.

  11. Physiological Responses of Zea mays Seedlings to Interactions Between Cadmium and Salinity

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of 0, 2.5, 5.0, and 10.0 μmol/L Cd2+ (Cd(NO3)2·4H2O) and 0, 10, 25, 50, and 100 mmol/L NaCl on growth,photosynthesis and the content of some ions in maize (Zea mays L.) were investigated in the present study. With increasing concentrations of Cd2+ or NaCl alone in Hoagland nutrient solution, the chlorophylls and starch content decreased. Combination treatment with salinity and cadmium increased the negative effects observed following the two stresses alone. Plants exhibiting growth retardation in response to one mild stress factor (25-50 mmol/L NaCl) became more tolerant to the other stress factor (Cd). The exposure of plants to cadmium caused a partial reversal of the effects of salinity. Root and shoot growth, ion accumulation and levels of photosynthetic pigments were improved at moderate concentrations of the two stress factors imposed jointly.

  12. Characterization and Fine Mapping of a Necrotic Leaf Mutant in Maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    Lijing Wang; Shuai Han; Shiyi Zhong; Haizhong Wei; Yanjun Zhang; Yan Zhao; Baoshen Liu

    2013-01-01

    Maize (Zea mays L.) is a commercially important crop.Its yield can be reduced by mutations in biosynthetic and degradative pathways that cause death.In this paper,we describe the necrotic leaf (nec-t) mutant,which was obtained from an inbred line,81647.The nec-t mutant plants had yellow leaves with necrotic spots,reduced chlorophyll content,and the etiolated seedlings died under normal growth conditions.Transmission electron microscopy revealed scattered thylakoids,and reduced numbers of grana lamellae and chloroplasts per cell.Histochemical staining suggested that spot formation of nec-t leaves might be due to cell death.Genetic analysis showed that necrosis was caused by the mutation of a recessive locus.Using simple sequence repeat markers,the Nec-t gene was mapped between mmc0111 and bnlg2277 on the short arm of chromosome 2.A total of 1287 individuals with the mutant phenotype from a F2 population were used for physical mapping.The Nec-t gene was located between markers T31 and H8 within a physical region of 131.7 kb.

  13. Assessment of the Maize (Zea mays-Mucuna (Mucuna deeringianum Bort Agroecosystem

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    Carlos E. Aguilar-Jimenez

    2012-01-01

    Full Text Available Problem statement: In Selva de Chiapas, Mexico, the traditional farming technique of slash-fell-burn used on hillside fields has caused severe soil deterioration. Consequently, indigenous farmers reacted by developing several agroecological practices that improve the physical, chemical and biological fertility of the soils. Standing out among these techniques is the use of Mucuna (Mucuna deeringianum Bort. in rotation with maize (Zea mays L. Approach: The objective of this study was to determine the effect of the maize-mucuna system on soil fertility, ecosystem diversity and maize crop yield. The study was conducted in the Tulija Valley, Chiapas, in the autumn-winter growing season (November-April. A completely random design was applied to four periods of consecutive maize-mucuna cropping (0, 5, 10 and 15 years in order to analyze the most significant variables related to soils, weeds, seed bank and yield. Results: The results obtained reveal the higher nutrient concentration in the topsoil (0-15 cm and better crop yield in the treatments with Mucuna rotation. No direct relationship was observed between nutrient content and duration of maize-mucuna system usage. However, the diversity of weeds and similarity of species both diminished where this farming method was used. Conclusion/Recommendations: It was determined that the use of the maize-mucuna agroecosystem helps to increase and maintain agroecological sustainability, supporting this practice that has been adapted and utilized by indigenous Choles for more than 30 years.

  14. Starch Mobilization in Ultradried Seed of Maize (Zea mays L.) During Germination

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng WANG; Xin-Ming JING; Jian LIN

    2005-01-01

    The effects of ultradry storage on the starch mobilization in maize (Zea mays L.) seed after aging were investigated. The results indicated that there were no significant differences in the content of ATP,starch, and soluble sugar, as well as the activity of amylase, between ultradried seeds and seeds stored at -20 ℃ during germination. These results were consistent with the higher level of vigor of the ultradried seed. Sieve tube introduction of a fluorescence dye (carboxyl fluoresceindiacetate) and laser confocal microscopy were used to study the development of plasmodesmata in the ultradried seeds. The results indicated that plasmodesmata developed well in ultradried seeds. Fluorescence analysis also showed that the fluorescence intensity in the radicle of ultradried seeds was stronger than that in seeds with a higher moisture content. This suggests that ultradry treatment has no adverse effects on the seeds. After seed imbibition, cell orgaelles could be resumed. It is concluded that ultradry seed storage is beneficial for maintaining seed vigor and that starchy mobilization proceeds regularly during germination.

  15. Efecto vasodilatador mediado por óxido nítrico del extracto hidroalcohólico de Zea mays L. (maíz morado en anillos aórticos de rata Vasodilator effect mediated by nitric oxide of the Zea mays L (andean purple corn hydroalcoholic extract in aortic rings of rat

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    Oscar Moreno-Loaiza

    2010-12-01

    Full Text Available Objetivo. Evaluar la respuesta vasodilatadora e inhibidora de la vasoconstricción del extracto hidroalcohólico de Zea mays L. (maíz morado y determinar si esta respuesta es mediada por óxido nítrico (NO. Materiales y métodos. Se obtuvo un extracto de las corontas de maíz morado maceradas durante ocho días en etanol al 70%, y posterior concentración del producto. Se trabajó con anillos aórticos de rata en cámara de órganos aislados, bañada con solución Krebs-Hensleit (K-H y se registró la actividad vasomotora con un transductor de tensión isométrica. Se produjo una contracción basal con KCl 120 mM sobre la cual determinó el efecto vasodilatador de tres dosis del extracto: 0,1; 0,5 y 1,0 mg/mL. Se utilizó L-NG-Nitroarginina metil ester (L-NAME para comprobar que la vasodilatación depende de la óxido nítrico sinteasa (NOs. Luego se comparó la inhibición de la contracción vascular tras la incubación durante 30 minutos, con extracto de maíz morado y captopril 10-5 M. Resultados. Se observó una reducción de la contracción máxima (100% a 85,25 ± 2,60%, 77,76 ± 3,23% y 73,3 ± 4,87%, para las dosis de 0,1; 0,5 y 1,0 mg/mL, respectivamente. La vasodilatación fue inhibida por la incubación previa con L-NAME. El extracto de maíz morado no inhibió la contracción vascular, a diferencia del captopril (reducción a 75,27 ± 8,61%. Conclusión. El extracto hidroalcohólico de Zea mays L produce vasodilatación dependiente de la síntesis de NO.Objective: To evaluate the vasodilator response of the hydroalcoholic extract of Zea mays L. (Andean purple corn and to determine if this response is mediated by nitric oxide (NO. Material and methods: We obtained an extract by maceration for eight days of Andean purple corn cobs in 70% ethanol and subsequent concentration of the product. Thoracic aortic rings were evaluated in an isolated organ chamber, bathed with Krebs-Hensleit solution (KH, and vasomotor activity was recorded

  16. Plantas de cobertura e seus efeitos sobre o feijoeiro em plantio direto

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    Oliveira Tadário Kamel de

    2002-01-01

    Full Text Available O objetivo deste trabalho foi estimar o rendimento de matéria fresca, matéria seca e o acúmulo de nutrientes da fitomassa produzida por milheto (Pennisetum americanum (L. Leek, sorgo (Sorghum bicolor (L. Moench, milho (Zea mays L., mucuna-preta (Stizolobium aterrimum e feijão-de-porco (Canavalia ensiformis (L. DC., em cultivo exclusivo e consorciado, e seus efeitos sobre o feijoeiro (Phaseolus vulgaris L. cv. Carioca em plantio direto. Os tratamentos consistiram no cultivo exclusivo das espécies e nos consórcios das gramíneas com as leguminosas. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repetições. O sorgo em cultivo exclusivo apresenta maior produtividade de matéria fresca e, juntamente com o milheto exclusivo e o consórcio milheto e mucuna-preta, maior produtividade de matéria seca. Ocorre maior acúmulo de nutrientes no milheto exclusivo e consorciado com mucuna-preta. Posteriormente, realizou-se o plantio direto do feijoeiro, cujo rendimento de grãos é influenciado pelas diferentes palhadas das plantas de cobertura no sistema plantio direto, sendo mais afetado pela espécie produtora de palha do que pela sua forma de cultivo.

  17. Recursos y enlaces sobre comunidades de aprendizaje

    OpenAIRE

    Ferrer Esteban, Gerard

    2005-01-01

    Obras y artículos sobre el proyecto Comunidades de Aprendizaje desarrollado en el Estado español. Tesis doctorales sobre comunidades de aprendizaje. Fundamentación teórica de las comunidades de aprendizaje. Sitios en Internet relacionados con las comunidades de aprendizaje y proyectos afines de desarrollo comunitario en contextos escolares.

  18. On GAMER, plataforma de continguts sobre videojocs

    OpenAIRE

    Villegas Bonachera, José Ricardo

    2015-01-01

    Desenvolupament d'una plana web amb disseny responsiu sobre videojocs en català a partir del gestor de continguts WordPress. Desarrollo de una página web con diseño responsivo sobre videojuegos en catalán a partir del gestor de contenidos WordPress. Bachelor thesis for the Multimedia program on Computer Science.

  19. The impact of wheat production on the occurrence of mycotoxins DON (deoxynivalenol and ZEA (zearalenone on wheat grains (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Lena TAJNŠEK

    2015-12-01

    Full Text Available The current study has been conceived to draw attention to the factors that should be avoided in the production of cereal grains (such as high doses of nitrogen by analysing differences in cereal grain contamination with mycotoxins DON (deoxynivalenol and ZEA (zearalenone, depending on methods of wheat production. We studied the occurrence of DON and ZEA at very different production intensities in the ‘Reska’ and ‘Savinja’ wheat cultivars which were grown in a long-term field experiment (designed in 1992 at Jable near Ljubljana in the years 2006 and 2008. The cultivars ‘Reska’ and ‘Savinja’ have been considered in crop rotation of wheat-maize-oats in 5 methods of production with variants ranging organic up to intensely conventional. The results obtained have shown that adequately chosen agri-technical measures significantly reduced the risk of contamination of wheat flour by the mycotoxins DON and ZEA. Too abundant N (nitrogen fertilization of either inorganic or organic origin is to be avoided. The extensive wheat growing reduces considerably the risk of DON and ZEA occurrence in comparison to the intensive one. Cultivar plays an important role in this process. The comparison of both cultivars has shown that the cultivar ‘Savinja’ was more resistant to the contamination with DON and ZEA than the cultivar ‘Reska’.

  20. Escenarios sobre el orden internacional

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    Luis Dallanegra Pedraza

    2012-01-01

    Full Text Available Luego de las grandes cambios que se dieron con la caída del Muro de Berlín y la desintegración en la URSS, se analizan, desde una perspectiva realista-sistémicaestructural, los componentes que intervienen en la generación del orden mundial, qué factores intervienen y cuáles son las diferentes aspiraciones respecto de las características que debería tener. Se tiene en especial consideración la creciente heterogeneización del sistema y la manera en que actores transnacionales operan como motores del futuro orden, predominando por sobre las posibilidades del actor históricamente dominante: el Estado-Nación. Se estudian las características principales del funcionamiento del sistema internacional y el significado de su marco institucional.

  1. Constitucional sobre la justicia ordinaria

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    José Luis Cea Egaña

    2005-01-01

    Full Text Available El artículo analiza el efecto vinculante y de irradiación de las sentencias del Tribunal Constitucional sobre el conjunto del ordenamiento jurídico y de sus órganos. El autor toma partido por la consideración de la ratio decidendi del fallo como vinculante junto al dictum de la sentencia respectiva. Se plantea la necesidad que la LOC del Tribunal Constitucional explicite los efectos vinculantes de los fallos respecto de los tribunales ordinarios y especiales. Finalmente analiza los efectos de la res iudicata en el ámbito del control reparador de constitucionalidad de preceptos legales en control concreto y en control abstracto.

  2. Historicismo: notas sobre um paradigma

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    José D’Assunção Barros

    2012-08-01

    Full Text Available Este artigo tem por objetivo desenvolver algumas considerações sobre o Historicismo e sua possibilidade de ser examinado como um dos paradigmas que concorrem para o estabelecimento de uma história científica no século XIX. O primeiro ponto tratado é relativo às origens do paradigma Historicista na transição do século XVIII para o século XIX. Na sequência, aproximamo-nos da apropriação conservadora do paradigma historicista no novo contexto no qual a burguesia européia está assentada no Poder, combinando-se com a consolidação dos modernos estados-nações. A especificação das características deste paradigma constituem o principal ponto de análise

  3. As monografias sobre plantas medicinais

    Directory of Open Access Journals (Sweden)

    Valdir F. Veiga Junior

    2008-09-01

    Full Text Available As monografias sobre plantas medicinais ou drogas vegetais contêm informações para atender não somente aos órgãos de regulamentação, mas também às empresas industriais farmacêuticas e farmácias, e mesmo ao público consumidor. Este artigo revê as monografias da Comissão E, do American Botanical Council, ESCOP, PDR e da Organização Mundial de Saúde em suas origens, objetivos e formatos. Duas publicações recentemente organizadas pela FIOCRUZ do Rio de Janeiro e as contribuições da Farmacopéia Brasileira também são avaliadas.

  4. Inseticidas para o controle da traça-do-tomateiro e broca-grande e seu impacto sobre Trichogramma pretiosum Insecticides for the control of the South American tomato pinworm and the corn earworm and impact of those products on Trichogramma pretiosum

    OpenAIRE

    Marina Castelo Branco; Ludimilla A. Pontes; Pablo S.T. Amaral; Manoel V. Mesquita Filho

    2003-01-01

    Experimentos de campo foram conduzidos entre maio e outubro de 2000 para determinar a eficiência de diversos inseticidas para o controle de Tuta absoluta e Helicoverpa zea e o impacto desses produtos sobre a emergência do parasitóide Trichogramma pretiosum. Os inseticidas testados, bem como as doses em g i.a./ha foram: metoxifenozide (120; 144), clorpirifós (540; 675), tiacloprid (72; 96) e triflumuron (144). O delineamento experimental foi de blocos ao acaso com oito tratamentos (inseticidas...

  5. FORMAS DE APLICAÇÃO DO FERTILIZANTE E NÍVEIS DE IRRIGAÇÃO NO DESENVOLVIMENTO DO MILHO (Zea mays) FERTILIZER APPLICATION METHODS AND IRRIGATION LEVELS ON EARLY (Zea mays L.) DEVELOPMENT

    OpenAIRE

    José Xavier de Almeida Neto; Jorge Luiz do Nascimento

    2007-01-01

    O desenvolvimento inicial da cultura do milho (Zea mays L.) foi avaliado através da produção de matéria seca das raízes (MR) e da parte aérea (MA) em um experimento conduzido em vasos, abrigado sob uma estufa do tipo túnel baixo. O...

  6. Efeitos da densidade e proporção de plantas de milho (Zea mays L. e caruru (Amaranhus retroflexus L. em competição Density and porportion effects among corn (Zea mays L. and pigweed (Amaranthus retroflexus L. under competition

    Directory of Open Access Journals (Sweden)

    Pedro J. Christoffoleti

    1996-01-01

    Full Text Available A maioria dos estudos de competição, entre plantas daninhas e cultivadas, conduzidos nos últimos anos, procuram quantificar a interferência que as plantas daninhas causam sobre as culturas; no entanto, poucos destes trabalhos estudam mecanisticamente os efeitos da densidade e da proporção de plantas em uma mistura de espécies, a importância da competição intra e interespecífica e a diferenciação de nicho ecológico. Desta forma, foi desenvolvida a presente pesquisa com o objetivo principal de descrever as interações competitivas e os índices de competitividade entre plantas de milho (Zea mays L. e caruru (Amarathus retroflexus L.. A metodologia utilizada foi a de um experimento substitutivo com densidade total de 400 plantas/m2 e 5 proporções, além da monocultura que variou de 50 a 800 plantas/m2, sendo conduzido no delineamento experimental de blocos casualizados, com quatro repetições. Os resultados obtidos foram analisados pelo método convencional de análise de experimentos substitutivos e pelo método da produção recíproca total e por planta. O milho foi um competidor muito mais agressivo que o caruru, sendo que para a planta cultivada a competição intraespecífica é mais importante que a competição interespecífica. O contrário é verdadeiro para o caruru, ou seja, a competição interespecífica é mais importante que a intraespecífica. Ambas espécies de plantas estão competindo pelos mesmos fatores de crescimento, pois o índice que mede a diferenciação de nicho ecológico é menor que 1,0. A determinação da influência da densidade e proporção de espécies em estudos de competição entre plantas é muito importante para a compreensão das interações competitivas.Most of the competition studies between weeds and crops conducted lately quantify the interference that the weeds cause to crops; however, these researches do not show mechanistically neither the effects of density and proportion of

  7. Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency.

    Science.gov (United States)

    Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-11-01

    Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants.

  8. Cloning, Localization and Expression Analysis of ZmHsf-like Gene in Zea mays

    Institute of Scientific and Technical Information of China (English)

    LI Hui-cong; LI Guo-liang; LIU Zi-hui; ZHANG Hong-mei; ZHANG Yan-min; GUO Xiu-lin

    2014-01-01

    Using homology cloning method, a heat shock transcription factor (Hsf) like gene, ZmHsf-like, was cloned from maize (Zea mays) leaves. Sequence analyses showed that the open reading frame (ORF) of the gene ZmHsf-like is 1 404 bp long, encoding 467 amino acids. The sequence of amino acids encoded by ZmHsf-like contains the most conserved and typical DNA-binding domain of Hsf family. By bombardment into onion epidermis, we ifrstly found that the ZmHsf-like was subcellular-located in nucleus. NucPred analysis revealed there is a classic NLS of KKRR peptide in protein. Real-time PCR showed that ZmHsf-like gene expressed in leaves, stems and roots of maize seedlings under normal growth conditions, and the highest expression level was in roots, lower in leaves and the lowest in stems. The ZmHsf-like gene expression could be up-regulated by heat shock, PEG, ABA, and H2O2 in different degrees, among which the heat shock and ABA worked more efifciently. Obvious differences of the peak value and its corresponding time point of ZmHsf-like gene expression were observed among treatments. Experiments with inhibitor further suggested that the up-regulation ZmHsf-like gene expression of heat shock was H2O2-dependent while the induction of ZmHsf-like with PEG did not depend on the existence of H2O2. These results pointed out that ZmHsf-like gene probably regulates responsive reactions to abiotic stresses especially heat shock and drought through different signal transduction pathways.

  9. Expression and characterization of plasma membrane aquaporins in stomatal complexes of Zea mays.

    Science.gov (United States)

    Heinen, Robert B; Bienert, Gerd Patrick; Cohen, David; Chevalier, Adrien S; Uehlein, Norbert; Hachez, Charles; Kaldenhoff, Ralf; Le Thiec, Didier; Chaumont, François

    2014-10-01

    Stomata, the microscopic pores on the surface of the aerial parts of plants, are bordered by two specialized cells, known as guard cells, which control the stomatal aperture according to endogenous and environmental signals. Like most movements occurring in plants, the opening and closing of stomata are based on hydraulic forces. During opening, the activation of plasma membrane and tonoplast transporters results in solute accumulation in the guard cells. To re-establish the perturbed osmotic equilibrium, water follows the solutes into the cells, leading to their swelling. Numerous studies have contributed to the understanding of the mechanism and regulation of stomatal movements. However, despite the importance of transmembrane water flow during this process, only a few studies have provided evidence for the involvement of water channels, called aquaporins. Here, we microdissected Zea mays stomatal complexes and showed that members of the aquaporin plasma membrane intrinsic protein (PIP) subfamily are expressed in these complexes and that their mRNA expression generally follows a diurnal pattern. The substrate specificity of two of the expressed ZmPIPs, ZmPIP1;5 and ZmPIP1;6, was investigated by heterologous expression in Xenopus oocytes and yeast cells. Our data show that both isoforms facilitate transmembrane water diffusion in the presence of the ZmPIP2;1 isoform. In addition, both display CO2 permeability comparable to that of the CO2 diffusion facilitator NtAQP1. These data indicate that ZmPIPs may have various physiological roles in stomatal complexes.

  10. Pengaruh Jarak Tanam dan Pemangkasan terhadap Kualitas Silase Dua Varietas Jagung (Zea mays L.

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    La Karimuna

    2009-04-01

    Full Text Available Effects of crop arrangement and cutting on the silages quality of two varieties of maize (Zea mays L. ABSTRACT. The objective of this experiment was to study the interaction effect of varieties, spacing and cutting on the quality of silage as foodstuff. The experiment had been conducted from January to April, 2007 at the experimental Garden of Faculty of Agriculture, University of Haluoleo. This experiment was arranged in Split-Split plot design with three factors. The first factor was variety as main plot, consisting of BISI-2 variety and local variety; the second factor was space arrangement as sub plot, consisting of 60 cm x 40 cm (J1, 75 cm x 40 cm (J2, 90 cm x 40 cm (J3, the third factor was cutting period as sub plot, consisting of no cutting (Po, cutting on 40 days (P1, and cutting on 55 days (P2. So that there were 2 x 3 x 3 x 3 = 54 experimental units. Analysis of variance was applied to know the effect of treatment. If so, least significant difference (LSD 0.05 (95 % confidence level was used. Variables observed was plant growth determining silages quality, consisting of quality of crude protein, crude fiber, crude fat, and water. Results of research revealed that interaction affect of spacing and cutting periods on 40 days of BISI-2 variety gave the best yield of plant growth for plant height. While the local variety tended to adverse effect of cutting. However, the quality of silages of two varieties tended to be similar. Every crop spacing had a positive effect of cutting on 40 days. The best quality of silages of two varieties was resulted from the interaction between spacing 75 cm x 40 cm and cutting of 40 days.

  11. Comparative Proteomic Analysis of the Response of Maize (Zea mays L.) Leaves to Long Photoperiod Condition.

    Science.gov (United States)

    Wu, Liuji; Tian, Lei; Wang, Shunxi; Zhang, Jun; Liu, Ping; Tian, Zhiqiang; Zhang, Huimin; Liu, Haiping; Chen, Yanhui

    2016-01-01

    Maize (Zea mays L.), an important industrial material and food source, shows an astonishing environmental adaptation. A remarkable feature of its post-domestication adaptation from tropical to temperate environments is adaptation to a long photoperiod (LP). Many photoperiod-related genes have been identified in previous transcriptomics analysis, but proteomics shows less evidence for this mechanism of photoperiod response. In this study, we sampled newly expanded leaves of maize at the three- and six-leaf stages from an LP-sensitive introgression line H496, the donor CML288, LP-insensitive inbred line, and recurrent parent Huangzao4 (HZ4) grown under long days (15 h light and 9 h dark). To characterize the proteomic changes in response to LP, the iTRAQ-labeling method was used to determine the proteome profiles of plants exposed to LP. A total of 943 proteins differentially expressed at the three- and six-leaf stages in HZ4 and H496 were identified. Functional analysis was performed by which the proteins were classified into stress defense, signal transduction, carbohydrate metabolism, protein metabolism, energy production, and transport functional groups using the WEGO online tool. The enriched gene ontology categories among the identified proteins were identified statistically with the Cytoscape plugin ClueGO + Cluepedia. Twenty Gene Ontology terms showed the highest significance, including those associated with protein processing in the endoplasmic reticulum, splicesome, ribosome, glyoxylate, dicarboxylate metabolism, L-malate dehydrogenase activity, and RNA transport. In addition, for subcellular location, all proteins showed significant enrichment of the mitochondrial outer membrane. The sugars producted by photosynthesis in plants are also a pivotal metabolic output in the circadian regulation. The results permit the prediction of several crucial proteins to photoperiod response and provide a foundation for further study of the influence of LP treatments on

  12. Valenzuela y Zea: Científicos Criollos en la Independencia Americana

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    Diana Elvira Soto Arango

    2014-01-01

    Full Text Available 15 Rev. hist.educ.latinoam - Vol. 16 No. 23, julio - diciembre 2014 - ISSN 0122-7238 – pp. 15 - 40 El objeto de esta investigación se centró en los criollos Zea y Valenzuela en la faceta de los cambios y participación que presentaron en el período de la Independencia americana. A estos dos criollos neogranadinos les unió José Celestino Mutis, en su formación científica y ubicación profesional, y llegaron a ocupar la Subdirección de la Real Expedición Botánica de Nueva Granada. El método se centró en la historia social de la ciencia y la metodología utilizada se sustentó en la historia comparada en indicadores de análisis como: formación, trayectoria profesional, participación política y análisis de los discursos relevantes que pronunciaron en el proceso de la independencia. Las fuentes se localizaron en archivos de España, Colombia y Venezuela. En conclusión, la vida política de estos dos botánicos se une en un discurso político mediado por el pensamiento ilustrado de impulsar cambios en la educación y el desarrollo de la industria y el comercio, donde las ciencias útiles con el estudio de los recursos naturales de su patria marcaban el derrotero de la nueva concepción para el imaginario de nación de la élite criolla neogranadina.

  13. β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

    Science.gov (United States)

    Shaw, Arun K; Bhardwaj, Pardeep K; Ghosh, Supriya; Roy, Sankhajit; Saha, Suman; Sherpa, Ang R; Saha, Samir K; Hossain, Zahed

    2016-02-01

    The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.

  14. Concurrent Measurements of Oxygen and Carbon Dioxide Exchange during Lightflecks in Maize (Zea mays L.).

    Science.gov (United States)

    Krall, J. P.; Pearcy, R. W.

    1993-11-01

    Leaves of maize (Zea mays L.) were enclosed in a temperature-controlled cuvette under 35 Pa (350 [mu]bars) CO2 and 0.2 kPa (0.2%)O2 and exposed to short periods (1-30 s) of illumination (light-flecks). The rate and total amount of CO2 assimilated and O2 evolved were measured. The O2 evolution rate was taken as an indicator of the rate of photosynthetic noncyclic electron transport (NCET). In this C4 species, the response of electron transport during the lightflecks qualitatively mimicked that of C3 species previously tested, whereas the response of CO2 assimilation differed. Under short-duration lightflecks at high photon flux density (PFD), the mean rate of O2 evolution was greater than the steady-state rate of O2 evolution under the same PFD due to a burst of O2 evolution at the beginning of the lightfleck. This O2 burst was taken as indicating a high level of NCET involved in the buildup of assimilatory charge via ATP, NADPH, and reduced or phosphorylated metabolites. However, as lightfleck duration decreased, the amount of CO2 assimilated per unit time of the lightfleck (the mean rate of CO2 assimilation) decreased. There was also a burst of CO2 from the leaf at the beginning of low-PFD lightflecks that further reduced the assimilation during these lightflecks. The results are discussed in terms of the buildup of assimilatory charge through the synthesis of high-energy metabolites specific to C4 metabolism. It is speculated that the inefficiency of carbon uptake during brief light transients in the C4 species, relative to C3 species, is due to the futile synthesis of C4 cycle intermediates. PMID:12231981

  15. Effects of Cadmium on Polar Lipid Composition and Unsaturation in Maize (Zea mays) in Hydroponic Culture

    Institute of Scientific and Technical Information of China (English)

    Radhouane Chaffai; Tinni Nouhou Seybou; Brahim Marzouk; Ezzedine El Ferjani

    2007-01-01

    This study aimed to evaluate the effect of Cd exposure (100 μmol/L) on polar lipid composition, and to examine the level of fatty acid unsaturation in maize (Zea mays L.).In roots, the level of 16:0 and monounsaturated fatty acids (16:1+18:1)decreased in phosphatidylcholine (PC) and phosphatidylethanolamine (PE).In contrast, the proportion of unsaturated 18-C fatty acid species showed an opposite response to Cd.The content, on the other hand, of PC, PE, digalactosyldiacylglycerol (DGDG), and steryl lipids increased in roots (2.9-, 1.6-, 5.3-, and 1.7-fold increase, respectively).These results suggest that a more unsaturated fatty acid composition than found in control plants with a concomitant increase in polar lipids may favor seedling growth during Cd exposure.However, the observed increase in the steryl lipid (SL) : phospholipid (PL) ratio (twofold), the decrease in monogalactosyldiacylglycerol (MGDG) : DGDG ratio, as well as the induction of lipid peroxidation in roots may represent symptoms of membrane injury.In shoots, the unsaturation level was markedly decreased in PC and phosphatidylglycerol (PG) after Cd exposure, but showed a significant increase in sulfoquinovosyldiacylglycerol (SQDG),MGDG and DGDG.The content of PG and MGDG was decreased by about 65%, while PC accumulated to higher levels (4.4-fold increase).Taken together, these changes in the polar lipid unsaturation and composition are likely to be due to alterations in the glycerolipid pathway.These results also support the idea that the increase in overall unsaturation plays some role in enabling the plant to withstand the metal exposure.

  16. Growth responses of plants to various concentrations of nitrogen dioxide. [Helianthus annuus L. ; Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Okano, K.; Totsuka, T.; Fukuzawa, T.; Tazaki, T.

    1985-01-01

    Sunflower Helianthus annuus L. and maize Zea mays L. plants in the vegetative phase were exposed to nitrogen dioxide (NO2) at 0.0 (control), 0.2, 0.5 and 1.0 ppm ( l liter ) for 2 weeks. The growth responses of the plants to NO2 were examined by the techniques of growth analysis. The sunflower plant was more susceptible to NO2 than the maize plant. Exposure to NO2 at 0.2 ppm slightly stimulated the growth of the sunflower plants. The net assimilation rate (NAR) was also significantly increased when the plants were exposed to 0.2 ppm NO2. Exposures to NO2 at 0.5 or more significantly reduced the dry weight of the sunflower plant. Of the component parts, the roots and stems were severely affected, while the leaves were less affected. This resulted in an elevated shoot/root ratio. The net assimilation rate of both species was reduced by the exposures to NO2 at 0.5 ppm or more, while, in contrast, the leaf area ratio (LAR) was increased. The relative growth rate (RGR), the product of the NAR and the LAR, was therefore less affected by NO2. The increase in the LAR was overwhelmingly the result of an increase in the leaf weight ratio (LWR). These results imply that a reduction in photosynthetic efficiency induced by NO2 could be, in part, compensated for by an increase in assimilatory area, suggesting an adaptive growth response of the plants to air pollutant stresses.

  17. Calcium ion dependency of ethylene production in segments of primary roots of Zea mays

    Science.gov (United States)

    Hasenstein, K. H.; Evans, M. L.

    1986-01-01

    We investigated the effect of Ca2+ on ethylene production in 2-cm long apical segments from primary roots of corn (Zea mays L., B73 x Missouri 17) seedlings. The seedlings were raised under different conditions of Ca2+ availability. Low-Ca and high-Ca seedlings were raised by soaking the grains and watering the seedlings with distilled water or 10 mM CaCl2, respectively. Segments from high-Ca roots produced more than twice as much ethylene as segments from low-Ca roots. Indoleacetic acid (IAA; 1 micromole) enhanced ethylene production in segments from both low-Ca and high-Ca roots but auxin-induced promotion of ethylene production was consistently higher in segments from high-Ca roots. Addition of 1-aminocyclopropane-1-carboxylic acid (ACC) to root segments from low-Ca seedlings doubled total ethylene production and the rate of production remained fairly constant during a 24 h period of monitoring. In segments from high-Ca seedlings ACC also increased total ethylene production but most of the ethylene was produced within the first 6 h. The data suggest that Ca2+ enhances the conversion of ACC to ethylene. The terminal 2 mm of the root tip were found to be especially important to ethylene biosynthesis by apical segments and, experiments using 45Ca2+ as tracer indicated that the apical 2 mm of the root is the region of strongest Ca2+ accumulation. Other cations such as Mn2+, Mg2+, and K+ could largely substitute for Ca2+. The significance of these findings is discussed with respect to recent evidence for gravity-induced Ca2+ redistribution and its relationship to the establishment of asymmetric growth during gravitropic curvature.

  18. Optical Reflectance and Fluorescence for Detecting Nitrogen Needs in Zea mays L.

    Science.gov (United States)

    McMurtrey, J. E.; Middleton, E. M.; Corp. L. A.; Campbell, P. K. Entcheva; Butcher, L. M.; Daughtry, C. S. T.

    2003-01-01

    Nitrogen (N) status in field grown corn (Zea mays L.) was assessed using spectral techniques. Passive reflectance remote sensing and, both passive and active fluorescence sensing methods were investigated. Reflectance and fluorescence methods are reported to detect changes in the primary plant pigments (chlorophylls a and b; carotenoids) in higher plant species. As a general rule, foliar chlorophyll a (Chl a) and chlorophyll b (Chl b) usually exist in approx.3:l ratio. In plants under stress, Chl b content is affected before Chl a reductions occur. For reflectance, a version of the chlorophyll absorption in reflectance index (CARI) method was tested with narrow bands from the Airborne Imaging Spectroradiometer for Applications (ASIA). CARI minimizes the effects of soil background on the signal from green canopies. A modified CARI (MCARI) was used to track total Chl a levels in the red dip of the spectrum from the corn canopy. A second MCARI was used to track the auxiliary plant pigments (Chl b and the carotenoids) in the yellow/orange/red edge part of the reflectance spectrum. The difference between these two MCARI indices detected variations in N levels across the field plot canopies using ASIA data. At the leaf level, ratios of fluorescence emissions in the blue, green, red and far-red wavelengths sensed responses that were associated with the plant pigments, and were indicative of energy transfer in the photosynthetic process. N stressed corn stands could be distinguish from those with optimally applied N with fluorescence emission spectra obtained from individual corn leaves. Both reflectance and fluorescence methods are sensitive in detecting corn N needs and may be especially powerful in monitoring crop conditions if both types of information can be combined.

  19. Evaluating Corn (Zea Mays L.) N Variability Via Remote Sensed Data

    Science.gov (United States)

    Sullivan, D. G.; Shaw, J. N.; Mask, P. L.; Rickman, D.; Luvall, J.; Wersinger, J. M.

    2003-01-01

    Transformations and losses of nitrogen (N) throughout the growing season can be costly. Methods in place to improve N management and facilitate split N applications during the growing season can be time consuming and logistically difficult. Remote sensing (RS) may be a method to rapidly assess temporal changes in crop N status and promote more efficient N management. This study was designed to evaluate the ability of three different RS platforms to predict N variability in corn (Zea mays L.) leaves during vegetative and early reproductive growth stages. Plots (15 x 15m) were established in the Coastal Plain (CP) and Appalachian Plateau (AP) physiographic regions each spring from 2000 to 2002 in a completely randomized design. Treatments consisted of four N rates (0, 56, 112, and 168 kg N/ha) applied as ammonium nitrate (NH4N03) replicated four time. Spectral measurements were acquired via spectroradiometer (lambda = 350 - 1050 nm), Airborne Terrestrial Applications Sensor (ATLAS) (lambda = 400 - 12,500 nm), and the IKONOS satellite (lambda = 450 - 900 nm). Spectroradiometer data were collected on a biweekly basis from V4 through R1. Due to the nature of - satellite and aircraft acquisitions, these data were acquired per availability. Chlorophyll meter (SPAD) and tissue N were collected as ancillary data along with each RS acquisition. Results showed vegetation indices derived from hand-held spectroradiometer measurements as early as V6-V8 were linearly related to yield and tissue N content. ATLAS data was correlated with tissue N at the AP site during the V6 stage (r2 = 0.66), but no significant relationships were observed at the CP site. No significant relationships were observed between plant N and IKONOS imagery. Using a combination of the greenness vegetation index (GNDVI) and the normalized difference vegetation index (NDVI), RS data acquired via ATLAS and the spectroradiometer could be used to evaluate tissue N variability and estimate corn yield variability

  20. Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

    Science.gov (United States)

    Komoszynski, M.; Bandurski, R. S.

    1986-01-01

    Indole-3-acetyl-myo-inositol galactoside labeled with 3H in the indole and 14C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [3H]indole-3-acetyl-myo-inositol and [3H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumption concerning the equilibration of applied [3H]indole-3-acetyl-myo-inositol-[U-14C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetyl-myo-inositol and 1 picomole per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indole-acetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [3H]indole-3-acetyl-myo-inositol-[14C]galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [3H]indole-3-acetyl-myo-inositol-[14C]galactose supplies appreciable amounts of 14C to the shoot and both 14C and 3H to an uncharacterized insoluble fraction of the endosperm.

  1. The influence of calcium and pH on growth in primary roots of Zea mays

    Science.gov (United States)

    Hasenstein, K. H.; Evans, M. L.

    1988-01-01

    We investigated the interaction of Ca2+ and pH on root elongation in Zea mays L. cv. B73 x Missouri 17 and cv. Merit. Seedlings were raised to contain high levels of Ca2+ (HC, imbibed and raised in 10 mM CaCl2) or low levels of Ca2+ (LC, imbibed and raised in distilled water). In HC roots, lowering the pH (5 mM MES/Tris) from 6.5 to 4.5 resulted in strong, long-lasting growth promotion. Surprisingly, increasing the pH from 6.5 to 8.5 also resulted in strong growth promotion. In LC roots acidification of the medium (pH 6.5 to 4.5) resulted in transient growth stimulation followed by a gradual decline in the growth rate toward zero. Exposure of LC roots to high pH (pH shift from 6.5 to 8.5) also promoted growth. Addition of EGTA resulted in strong growth promotion in both LC and HC roots. The ability of EGTA to stimulate growth appeared not to be related to H+ release from EGTA upon Ca2+ chelation since, 1) LC roots showed a strong and prolonged response to EGTA, but only a transient response to acid pH, and 2) promotion of growth by EGTA was observed in strongly buffered solutions. We also examined the pH dependence of the release of 45Ca2+ from roots of 3-day-old seedlings grown from grains imbibed in 45Ca2+. Release of 45Ca2+ from the root into agar blocks placed on the root surface was greater the more acidic the pH of the blocks. The results indicate that Ca2+ may be necessary for the acid growth response in roots.

  2. Maize (Zea mays L.) performance in organically amended mine site soils.

    Science.gov (United States)

    Oladipo, Oluwatosin Gbemisola; Olayinka, Akinyemi; Awotoye, Olusegun Olufemi

    2016-10-01

    Organic amendments play an important role in the eco-friendly remediation of degraded mine site soils. This study investigated the quality (essential nutrients and heavy metal content) of maize grown on organically amended soils from three active mines in Nigeria. Soil samples were collected randomly at 0-15 cm depth, air-dried and sieved. Five kg of soil were amended with poultry manure and sawdust (poultry manure only, sawdust only, poultry manure-sawdust mixtures in 3:1, 2:1 and 1:1 ratios) at 10 g kg(-1). Maize (Zea mays L.) seeds were planted and watered for two consecutive periods of 8 weeks, with the control and treatment experiments set up in the screenhouse in quadruples. Harvested tissues were weighed, dried, ground and digested. Chemical properties were determined using standard methods while atomic absorption spectrophotometry was used to determine total metal concentrations (Ca, Mg, Fe, Zn, Pb, Cd and Cu). ANOVA was used to test for significant differences among treatment groups in the various parameters. Application of poultry manure-sawdust mixtures significantly (p < 0.05) enhanced tissue dry matter yield, as well as N, P, K, and Na contents while Zn, Cd, Cu and Pb were immobilized to approximately 50-100%. Treatment with sawdust alone reduced tissue nutrient content resulting in depressed plant yield while poultry manure only though enhanced crop yield, contained higher heavy metal contents. Soil amendments comprised of poultry manure-sawdust mixtures can be effective remediation strategy for mine site soils, as these organic materials help replenish soil nutrients, immobilize heavy metals, and enhance food productivity. PMID:27415409

  3. Proliferation of maize (Zea mays L.) roots in response to localized supply of nitrate

    Science.gov (United States)

    Granato, T. C.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    Maize (Zea mays L.) plants with two primary nodal root axes were grown for 8 d in flowing nutrient culture with each axis independently supplied with NO3-. Dry matter accumulation by roots was similar whether 1.0 mol m-3 NO3- was supplied to one or both axes. When NO3- was supplied to only one axis, however, accumulation of dry matter within the root system was significantly greater in the axis supplied with NO3-. The increased dry matter accumulation by the +N-treated axis was attributable entirely to increased density and growth of lateral branches and not to a difference in growth of the primary axis. Proliferation of lateral branches for the +N axis was associated with the capacity for in situ reduction and utilization of a portion of the absorbed NO3-, especially in the apical region where lateral primordia are initiated. Although reduced nitrogen was translocated to the -N axis, concentrations in the -N axis remained significantly lower than in the +N axis. The concentration of reduced nitrogen, as well as in vitro NO3- reductase activity, was greater in apical than in more basal regions of the +N axis. The enhanced proliferation of lateral branches in the +N axis was accompanied by an increase in total respiration rate of the axis. Part of the increased respiration was attributable to increased mass of roots. The specific respiration rate (micromoles CO2 evolved per hour per gram root dry weight) was also greater for the +N than for the -N axis. If respiration rate is taken as representative of sink demand, stimulation of initiation and growth of laterals by in situ utilization of a localized exogenous supply of NO3- establishes an increased sink demand through enhanced metabolic activity and the increased partitioning of assimilates to the +N axis responds to the difference in sink demand between +N and -N axes.

  4. Correlations between gravitropic curvature and auxin movement across gravistimulated roots of Zea mays

    Science.gov (United States)

    Young, L. M.; Evans, M. L.; Hertel, R.

    1990-01-01

    We compared the kinetics of auxin redistribution across the caps of primary roots of 2-day-old maize (Zea mays, cv Merit) seedlings with the time course of gravitropic curvature. [3H] indoleacetic acid was applied to one side of the cap in an agar donor and radioactivity moving across the cap was collected in an agar receiver applied to the opposite side. Upon gravistimulation the roots first curved upward slightly, then returned to the horizontal and began curving downward, reaching a final angle of about 67 degrees. Movement of label across the caps of gravistimulated roots was asymmetric with preferential downward movement (ratio downward/upward = ca. 1.6, radioactivity collected during the 90 min following beginning of gravistimulation). There was a close correlation between the development of asymmetric auxin movement across the root cap and the rate of curvature, with both values increasing to a maximum and then declining as the roots approached the final angle of curvature. In roots preadapted to gravity (alternate brief stimulation on opposite flanks over a period of 1 hour) the initial phase of upward curvature was eliminated and downward bending began earlier than for controls. The correlation between asymmetric auxin movement and the kinetics of curvature also held in comparisons between control and preadapted roots. Both downward auxin transport asymmetry and downward curvature occurred earlier in preadapted roots than in controls. These findings are consistent with suggestions that the root cap is not only the site of perception but also the location of the initial redistribution of effectors that ultimately leads to curvature.

  5. The effect and fate of water-soluble carbon nanodots in maize (Zea mays L.).

    Science.gov (United States)

    Chen, Jing; Dou, Runzhi; Yang, Zhongzhou; Wang, Xiaoping; Mao, Chuanbin; Gao, Xiang; Wang, Li

    2016-08-01

    In this study, the toxicity of water-soluble carbon nanodots (C-dots) to maize (Zea mays L.) and their uptake and transport in plants were investigated. After exposed in sand matrix amended with 0-2000 mg/L C-dots for 4 weeks, we found that the phytotoxicity of C-dots was concentration-dependent. C-dots at 250 and 500 mg/L showed no toxicity to maize. However, 1000 and 2000 mg/L C-dots significantly reduced the fresh weight of root by 57% and 68%, and decreased the shoot fresh weight by 38% and 72%, respectively. Moreover, in maize roots, the exposure of C-dots at 2000 mg/L significantly increased the H2O2 content and lipid peroxidation (6.5 and 1.65 times higher, respectively), as well as, the antioxidant enzymes activities, up to 2, 1.5, 1.9 and 1.9 times higher for catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase, respectively. On the other hand, C-dots were observed in detached root-cap cells, cortex and vascular bundle of roots and mesophyll cells of leaves through fluorescence microscopy analysis, suggesting that C-dots were absorbed and translocated systemically in maize. Remarkably, a certain amount of C-dots were excreted out from leaf blade. To our knowledge, this is the first study combined phenotypic observation with physiologic responses and bioaccumulation and translocation analysis of C-dots to investigate their effect and fate in maize. PMID:26694806

  6. Demographics and genetic variability of the new world bollworm (Helicoverpa zea) and the old world bollworm (Helicoverpa armigera) in Brazil.

    Science.gov (United States)

    Leite, Natália A; Alves-Pereira, Alessandro; Corrêa, Alberto S; Zucchi, Maria I; Omoto, Celso

    2014-01-01

    Helicoverpa armigera is one of the primary agricultural pests in the Old World, whereas H. zea is predominant in the New World. However, H. armigera was first documented in Brazil in 2013. Therefore, the geographical distribution, range of hosts, invasion source, and dispersal routes for H. armigera are poorly understood or unknown in Brazil. In this study, we used a phylogeographic analysis of natural H. armigera and H. zea populations to (1) assess the occurrence of both species on different hosts; (2) infer the demographic parameters and genetic structure; (3) determine the potential invasion and dispersal routes for H. armigera within the Brazilian territory; and (4) infer the geographical origin of H. armigera. We analyzed partial sequence data from the cytochrome c oxidase subunit I (COI) gene. We determined that H. armigera individuals were most prevalent on dicotyledonous hosts and that H. zea were most prevalent on maize crops, based on the samples collected between May 2012 and April 2013. The populations of both species showed signs of demographic expansion, and no genetic structure. The high genetic diversity and wide distribution of H. armigera in mid-2012 are consistent with an invasion period prior to the first reports of this species in the literature and/or multiple invasion events within the Brazilian territory. It was not possible to infer the invasion and dispersal routes of H. armigera with this dataset. However, joint analyses using sequences from the Old World indicated the presence of Chinese, Indian, and European lineages within the Brazilian populations of H. armigera. These results suggest that sustainable management plans for the control of H. armigera will be challenging considering the high genetic diversity, polyphagous feeding habits, and great potential mobility of this pest on numerous hosts, which favor the adaptation of this insect to diverse environments and control strategies.

  7. Demographics and genetic variability of the new world bollworm (Helicoverpa zea and the old world bollworm (Helicoverpa armigera in Brazil.

    Directory of Open Access Journals (Sweden)

    Natália A Leite

    Full Text Available Helicoverpa armigera is one of the primary agricultural pests in the Old World, whereas H. zea is predominant in the New World. However, H. armigera was first documented in Brazil in 2013. Therefore, the geographical distribution, range of hosts, invasion source, and dispersal routes for H. armigera are poorly understood or unknown in Brazil. In this study, we used a phylogeographic analysis of natural H. armigera and H. zea populations to (1 assess the occurrence of both species on different hosts; (2 infer the demographic parameters and genetic structure; (3 determine the potential invasion and dispersal routes for H. armigera within the Brazilian territory; and (4 infer the geographical origin of H. armigera. We analyzed partial sequence data from the cytochrome c oxidase subunit I (COI gene. We determined that H. armigera individuals were most prevalent on dicotyledonous hosts and that H. zea were most prevalent on maize crops, based on the samples collected between May 2012 and April 2013. The populations of both species showed signs of demographic expansion, and no genetic structure. The high genetic diversity and wide distribution of H. armigera in mid-2012 are consistent with an invasion period prior to the first reports of this species in the literature and/or multiple invasion events within the Brazilian territory. It was not possible to infer the invasion and dispersal routes of H. armigera with this dataset. However, joint analyses using sequences from the Old World indicated the presence of Chinese, Indian, and European lineages within the Brazilian populations of H. armigera. These results suggest that sustainable management plans for the control of H. armigera will be challenging considering the high genetic diversity, polyphagous feeding habits, and great potential mobility of this pest on numerous hosts, which favor the adaptation of this insect to diverse environments and control strategies.

  8. Puente sobre el rio Medway

    Directory of Open Access Journals (Sweden)

    Freeman, Fox, Ingenieros

    1963-02-01

    have been prestressed both longitudinally and transversally. Between the two circulation roadways an elastic barrier has been placed, supported on metal posts.El puente sobre el río Medway tiene la misión de salvar dicho río en el nuevo trazado de carretera necesario para aliviar el denso tráfico estival entre Dower y Londres. Está situado en las proximidades de la ciudad de Rochester. La estructura se ha construido utilizando las vías de concurso. De todos los tipos presentados se eligió una estructura de hormigón armado. La longitud total de la obra es de 1.000 m. Los tres tramos principales de la obra salvan el río. El central es de 152 m de luz, y los dos adyacentes son de 103 m cada uno. Los accesos tienen un total de 18 tramos, que arrojan una longitud de 654 m. La anchura del puente es de 34 m, y la calzada se ha subdividido en dos direcciones de tráfico de 7,30 m cada una y, además, se han dejado dos espaldones laterales de 2,40 m de anchura. En planta se puede admitir que el puente tiene una alineación recta con una ligerísima curva, y que en el plano vertical presenta una pendiente de desagüe entre las pilas 9 y 10. Los estribos son de hormigón armado: tipo celular el del este y de hormigón en masa el del oeste. Los estribos se apoyan sobre pilotes hexagonales de hormigón armado cuya circunferencia circunscrita tiene 55 cm de radio y de 12 a 20 m de longitud. Cuando el firme se hallaba a profundidades inferiores a 6 m, los estribos se cimentaban directamente sobre el firme. Las pilas constituyen pórtico y tienen una altura variable de 9 a 30 m sobre el nivel del suelo. Los tramos de acceso forman una estructura continua simplemente apoyada. Cada tramo se compone de ocho vigas longitudinales de 30 a 41 m de longitud y de 190 toneladas cada una. Estas vigas son del tipo pretensado y prefabricado. El tramo central es del tipo cantilever, constituido por dos brazos, de 30 m de longitud, formados por vigas cajón. Cada una de estas vigas consta

  9. La aplicación de abono organo-mineral: una alternativa para la producción de maíz (Zea mays L., en suelos pardos con carbonatos.

    Directory of Open Access Journals (Sweden)

    Ignacio Corrales Garriga

    2013-04-01

    Full Text Available RESUMEN Durante tres años se condujo un experimento en áreas del Instituto de Investigaciones de Viandas Tropicales (INIVIT de Camagüey, empleando diferentes abonos organo-mineral, con el objetivo de conocer su influencia en el rendimiento del maíz (Zea maiz, L, sobre un suelo Pardo Sialítico Mullido Carbonatado de pH ligeramente ácido, bajo contenido de P2O5 y medio de K2O y materia orgánica. Para las mezclas organo-mineral se emplearon como abonos orgánicos el estiércol vacuno y la cachaza y como fertilizantes minerales, el superfosfato triple y el cloruro de potasio. El organo-mineral se aplicó en el momento de la siembra a una dosis de 745 kg ha1 de acuerdo a cada tratamiento, los que fueron replicados 4 veces en un diseño de bloques al azar. Se midió el rendimiento y sus componentes y se tomaron muestras de suelo para conocer la variación de sus propiedades. Los datos fueron evaluados por un análisis de varianza de clasificación doble y se aplicó la prueba de rango múltiple de Duncan para un nivel de significación del 5 %. Los resultados muestran que el empleo de los abonos organo-minerales favorece el rendimiento, reducen los fertilizantes químicos a emplear y mejoran las propiedades del suelo. ORGANO-MINERAL FERTILIZER APPLICATION: AN ALTERNATIVE FOR PRODUCTION OF CORN (Zea mays L., IN SIALYTIC BROWN CARBONATED SOIL. ABSTRACT. For three years, an experiment was conducted in areas of the Research Institute (INIVIT Camaguey , using different organo- mineral fertilizers , in order to study its influence on the performance of maize ( Zea mays , L on a Fluffy Sialytic Brown Carbonated soil slightly acidic pH , low P2O5 and K2O and medium organic matter. For organo- mineral mixtures were used as organic fertilizers and cow manure and cachaza and mineral fertilizer, triple superphosphate and potassium chloride. The organo- mineral was applied at the time of planting at a dose of 745 kg ha1 according to each treatment, which

  10. Comparisons on Forage Yield and Feeding Value Between Zea mexicana,Yucao2 and Chuandan14-Zea mexicana Hybrid%玉草2号、川单14×墨西哥大刍草和墨西哥大刍草产量和饲用价值比较

    Institute of Scientific and Technical Information of China (English)

    冯云超; 唐祈林; 荣廷昭

    2011-01-01

    To understand the forage yields in different planting density as well as their feeding value in the optimum density, a field experiment which Zea mexicana and Zea mays -Zea mexicana hybrids (Yucao2 and Chuan-danl4 × Zea mexicana) used as the materials were designed by random block split plot design investigated. The main results were that the fresh and dry matter yields of the three forages, which showed the change of "low-high-low" with the increase of planting density. The fresh and dry matter yields were the highest in the Yucao2 and the lowest in Zea mexicana among all planting density. The yields of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and ether extract(EE) in Yucao2 and chuandanl4× Zea Mexicana were higher than in Zea mexicana significantly or high significant, however, the content of CP and EE was the highest in Zea Mexicana. The relative feeding value(RFV) in Yucao2 had no significance with that in Zea mexicana and were higher than in chuandanl4 × Zea mexicana significantly.%采用裂区设计,对不同种植密度下玉草2号、川单14×墨西哥大刍草和墨西哥大刍草产量以及最适密度下饲用价值进行研究.结果表明,在试验设计的密度下,玉草2号鲜、干草产量均最高,川单14×墨西哥大刍草其次,墨西哥大刍草最低;3种饲草其鲜、干草产量随密度增加呈"低-高-低"的变化趋势.最适密度下饲用价值比较表明,玉草2号和川单14×墨西哥大刍草粗蛋白、酸性洗涤纤维、中性洗涤纤维和粗脂肪4种饲用成分产量均显著或极显著高于墨西哥大刍草,其粗蛋白和粗脂肪含量均低于墨西哥大刍草;玉草2号和墨西哥大刍草相对饲用价值差异不显著,均显著高于川单14×墨西哥大刍草.

  11. Vulnerabilidad del mercado nacional del maíz (Zea mays L.) ante cambios exógenos internacionales

    OpenAIRE

    González Rojas, Karina

    2010-01-01

    El aumento de las importaciones de maíz (Zea mays L.), la reciente liberación comercial y la actual crisis energética global, pone en situación de vulnerabilidad al mercado nacional del grano. Para cuantificar los efectos que pudieran tener cambios exógenos internacionales en el mercado de maíz en México se formuló un modelo Armington para el año promedio 2004/2006. Los resultados obtenidos indican que el mercado nacional de maíz es vulnerable a cambios en la oferta y demanda mundial. Una red...

  12. Structural organization of the Helicoverpa zea gene encoding the precursor protein for pheromone biosynthesis-activating neuropeptide and other neuropeptides.

    OpenAIRE

    Ma, P W; Knipple, D C; Roelofs, W.L.

    1994-01-01

    Sex pheromone biosynthesis in a number of moth species is induced by a conserved 33-amino acid amidated neuropeptide PBAN (pheromone biosynthesis-activating neuropeptide). We have isolated and characterized the Helicoverpa zea PBAN cDNA corresponding to a 766-nucleotide mRNA that is expressed in the subesophageal ganglion of adult moths. This mRNA is encoded on a transcription unit comprising 6 exons. The longest open reading frame of the cDNA encodes a 194-amino acid precursor protein that c...

  13. Influence of corn (Zea mays L) seed processing with a locally produced sheller on seed quality and their damage

    OpenAIRE

    Pratima Pandey; Jwala Bajrachrya; S. Pokharel

    2013-01-01

    Maize (Zea mays dis.L.) is one of the most important staple crops in the world. Sindhupalchok, Kavre and Nuwakot were the three districts selected for the maize CBSP groups under the respective Agriculture Development Offices identified by CDD for the present study. Altogether 2x6x3 samples for the study were collected. Seed damage as broken seeds, damages on embryo, seed quality assessments like seed moisture content, pure seed percentage, seed vigor measured by root and shoot length, seed g...

  14. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  15. Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

    Science.gov (United States)

    Reisig, Dominic D; Reay-Jones, Francis P F

    2015-08-01

    Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits.

  16. Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

    Science.gov (United States)

    Reisig, Dominic D; Reay-Jones, Francis P F

    2015-08-01

    Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits. PMID:26314074

  17. Puente sobre el Oosterschelde, Holanda

    Directory of Open Access Journals (Sweden)

    Hoving, H. T.

    1967-03-01

    Full Text Available This new bridge, forming part of the Delta project, is made of concrete, and was built by successive overhangs. Precast units were mainly used. The bridge is 5,000 m long, and is 11.85 m wide. The main spans are 95 m in length, except one, which can be opened up to sea traffic, which is 40 m long. The free height of the bridge over the sea is 15 m, which is insufficient for large ships. This required that one of the spans, in deep water, should open up, on hinges, and provide free passage to large ships. The intermediate bridge supports are of special interest. They rest on piles which go down to 38 m. They are hollow, cylindrical, of 4.35 m external diameter, and are driven into the ground in several stages, as they penetrate through the sands at the bottom of the Oosterschelde. To drive them in, an excavating device, inside the pile, was utilised, and also a dredging and suction mechanism, to clean out the bottom, and allow the piles to sink by gravity. But when external friction did not allow this to happen, the piles were weighed down with up to 500 tons of ballast. A series of three of these piles, in a row, makes up each bridge support. A cross member over the pile heads supports, in turn, the bridge deck. The bridge was built in successive sections, overhanging from each support, and then finally connected with a central portion. Use of precast units has been very extensive, so that the bridge can be justiaflably regarded as being prefabricated.Este nuevo puente, que forma parte del Plan de obras denominadas del Delta, es de hormigón y se ha construido por el procedimiento de voladizos sucesivos, utilizando, en su mayor parte, elementos prefabricados. Tiene una longitud total de 5.000 m; una anchura de 11,85 m; tramos principales de 95 m de luz, salvo uno, levadizo, que tiene 40 m. La altura libre sobre las ag^uas del mar es de 15 m, que es insuficiente para las naves de gran tonelaje; esto exigió que uno de sus tramos, en aguas

  18. Somos un envase : Discursos sobre el aborto

    OpenAIRE

    Löcher, Jennifer Irene

    2014-01-01

    No hay persona que no tenga opinión acerca del asunto y, cada vez más, la sociedad argentina debate sobre la pregunta de si se debe legalizar/despenalizar el aborto o no. Nunca antes se habló tanto sobre el tema públicamente: se publican artículos en los diarios, hay manifestaciones a favor y hay manifestaciones en contra de la legalización del aborto. El siguiente trabajo pretende relevar y analizar discursos que circulan socialmente alrededor del debate sobre el aborto. (Párrafo extraíd...

  19. Concepciones sobre la docencia universitaria de calidad

    OpenAIRE

    Arbeláez López, Ruby; Fortes del Valle, M. Carmen; Grau Rubio, Claudia

    2008-01-01

    Con esta investigación hemos querido participar en el proceso de búsqueda y construcción del sentido de calidad aplicado a la docencia universitaria, con el objetivo general de evidenciar las concepciones sobre docencia de calidad que pueden deducirse de los procesos de evaluación de los profesores universitarios. Nuestra meta final intenta propiciar la revisión de las políticas educativas y el enriquecimiento de la cultura sobre docencia y sobre evaluación docente. La mayor aportación de nue...

  20. Sobre a psicopatologia dos atos

    Directory of Open Access Journals (Sweden)

    Roberto Calazans

    2015-07-01

    Full Text Available Este artigo pretende apresentar a psicopatologia dos atos a partir do esquema de Jacques Lacan sobre a angústia. Diferenciamos os acting-out, a passagem ao ato, os sintomas, as inibições e a angústia fazendo uma duplicação do esquema de Lacan levando em consideração os registros do simbólico, do real e do imaginário. Esse esquema permite uma abordagem da questão dos atos do sujeito sem cair em uma perplexidade do clínico, nem na confusão entre os atos e a ação. Permite também uma melhor orientação do clínico em relação às diversas modalidades de respostas subjetivas que não se restringem à questão sintomática, que é o campo inaugural da clínica psicanalítica desde a sua fundação por Sigmund Freud. Acreditamos contribuir, assim, para um maior esclarecimento desse esquema no ensino de Lacan e para que ele possa servir de orientação para o tratamento dos atos do sujeito na clínica.

  1. Estudo multicasos sobre atividades inovativas

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    Sonia Regina Hierro Parolin

    2013-09-01

    Full Text Available Em estudos sobre competitividade argumenta-se que as empresas necessitam de estratégias baseadas em inovações e de capacidades internas em constantes e intensas transformações, não somente nos padrões tecnológicos, mas também no encadeamento do processo de gestão das atividades inovativas, como processos dinâmicos, não lineares e diversificados, em função de múltiplos fatores dos ambientes interno e externo. Para contribuir com essas discussões, neste artigo apresenta-se um estudo multicasos em quatro indústrias de médio e grande portes, de segmentos, densidades tecnológicas e históricos com inovações diferentes entre si. Como principais resultados, salientam-se o encadeamento das atividades inovativas como parte de uma estratégia organizacional para obter resultados com inovação e a afluência de todas as pessoas, e não somente as alocadas em pesquisa e desenvolvimento, para o cumprimento dessa estratégia.

  2. PERSPECTIVAS INFANTILES SOBRE LA TERRITORIALIDAD

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    Noelia Enriz

    2009-12-01

    Full Text Available En este trabajo nos proponemos un acercamiento a las diversas ideas infantiles sobre el territorio habitado, en el contexto particular de la población mbyá guaraní de Misiones. La fragilidad territorialidad a la que es expuesta la población indígena en Argentina se manifiestan cotidianamente en diversas áreas. La población mbyá, ha sido surcada por los límites de los estados nacionales de Paraguay, Brasil y Argentina. La sedentarización y los cercamientos de tierras en los diferentes estados, han impulsado transformaciones de las lógicas de subsistencia, de habitación y organización comunitaria. En el caso de la provincia de Misiones la acreditación burocrática de los títulos de tierras se encuentra aplazada, el estado no se compromete con la concreción de este derecho.

  3. Puente colgante sobre el Lillebaelt

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    Ostenfeld, Chr.

    1971-09-01

    Full Text Available This bridge, which was opened to traffic in October 1970 over the Lillebaelt, is the first of its kind in Denmark. It consists of a central span of 600 m, and two lateral ones of 240 m length each. The suspension cables, each 1,500 m, are the world's largest prefabricated cables. The bridge has original features, such as flaps on the main box girder, and new design of the anchorage blocks. These and other details are described in the article.Inaugurado en octubre de 1970, el puente colgante sobre el Lillebselt es el primer puente danés de este tipo. Consta de un tramo central de 600 m y dos tramos laterales de 240 m. Los cables sustentantes son, con sus 1.500 m de longitud, los mayores cables prefabricados del mundo. El puente presenta características origínales —empleo de «flaps» en la vigacajón de la superestructura, concepción nueva de los macizos de anclaje...— que, junto con el sistema de ejecución y las demás particularidades de la obra, son descritas en el artículo.

  4. Los derechos de autor sobre obtenciones vegetales

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    Rosario Silva Gilli

    2015-01-01

    Full Text Available Contenido: Las creaciones en la agricultura. Los derechos de autor sobre obtenciones vegetales. El Convenio Internacional para la protección de las obtenciones vegetales (París 1961 y sus revisiones de Ginebra 1972, 1978,1991 Objeto de la protección legal. Condiciones del cultivar. Alcance de la protección. La protección de obtenciones vegetales en el Mercosur. Los Derechos de autor en el Mercosur. El Protocolo de Armonización de normas sobre Propiedad Intelectual en el Mercosur. El Acuerdo de Cooperación y facilitación sobre la protección de las obtenciones vegetales en los Estados Partes del Mercosur.  Alcance de la normativa Mercosur. Los Derechos sobre cultivares en Uruguay. Los Derechos de autor como derechos humanos. ¿Derechos de autor vs. derecho de propiedad intelectual? Reflexión final

  5. Effect of Nitrogen Nutritional Stress on Some Growth Parameters of Zea mays L. and Vigna unguiculata (L. Walp.

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    Akinbode Foluso OLOGUNDUDU

    2013-02-01

    Full Text Available This study investigated the responses of maize (Zea mays L. and cowpea (Vigna unguiculata L. Walp. seedlings growth parameters to nitrogen nutritional stress. This was with a view to determining whether nitrogen nutritional stress would retard or enhance maize and cowpea growth, partly, wholly or not at all through its effect on biomass accumulation and some morphological parameters. Germination of seeds was done using treated sand in sixty plastic pots. A group of the seedlings was nutrient stressed by administering 200 ml of complete nutrient solution minus nitrogen (-N while the other groups were fed with five times (X5N and ten times (X10N the optimal concentration of nitrogen and the last regime was fed with full nutrient solution (FN. The effects of optimal concentration and nitrogen stress on the growth rates (as measured by their fresh and dry weight were studied. The result of the growth analysis showed that there was increase in shoot height with supraoptimal concentrations of nitrogen treatments (X10N and X5N while there was a decrease in shoot height with minus nitrogen (-N regimes. The observed higher biomass (dry matter yield under the FN regimes in both Zea mays and Vigna unguiculata were attributed to optimal nutrient assimilation rate.

  6. Presence of Zea luxurians (Durieu and Ascherson Bird in Southern Brazil: Implications for the Conservation of Wild Relatives of Maize.

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    Natália Carolina de Almeida Silva

    Full Text Available Records of the occurrence of wild relatives of maize in South American lowlands are unprecedented, especially in sympatric coexistence with landraces. This fact is relevant, because regions of occurrence of wild relatives of cultivated plants should be a priority for conservation, even if they do not correspond to the center of origin of the species. The aim of this study was to identify and characterize the wild relatives of maize in the Far West of Santa Catarina, southern Brazil. Therefore, phenotypic characterization was performed for five populations, based on 22 morphological traits deemed as fundamental for classifying the species of the genus Zea, and validated through the characterization of chromosomal knobs of two populations. The occurrence and distribution of teosinte populations were described through semi-structured interviews applied to a sample of 305 farmers. A total of 136 teosinte populations were identified; 75% of them occur spontaneously, 17% are cultivated populations, and 8% occur both ways, for the same farm. Populations that were characterized morphologically had trapezoidal fruits mostly, upright tassel branch (4-18, non-prominent main branch and glabrous glumes, with two protruding outer ribs and 8 inner ribs, on average. Cytogenetic analysis identified 10 pairs of homologous chromosomes (2n = 20 with 26 knobs, located in the terminal region of all chromosomes. The similarity of these results with the information reported in the literature indicates that the five populations of wild relatives of maize in this region of Santa Catarina belong to the botanical species Zea luxurians.

  7. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  8. Presence of Zea luxurians (Durieu and Ascherson) Bird in Southern Brazil: Implications for the Conservation of Wild Relatives of Maize

    Science.gov (United States)

    2015-01-01

    Records of the occurrence of wild relatives of maize in South American lowlands are unprecedented, especially in sympatric coexistence with landraces. This fact is relevant, because regions of occurrence of wild relatives of cultivated plants should be a priority for conservation, even if they do not correspond to the center of origin of the species. The aim of this study was to identify and characterize the wild relatives of maize in the Far West of Santa Catarina, southern Brazil. Therefore, phenotypic characterization was performed for five populations, based on 22 morphological traits deemed as fundamental for classifying the species of the genus Zea, and validated through the characterization of chromosomal knobs of two populations. The occurrence and distribution of teosinte populations were described through semi-structured interviews applied to a sample of 305 farmers. A total of 136 teosinte populations were identified; 75% of them occur spontaneously, 17% are cultivated populations, and 8% occur both ways, for the same farm. Populations that were characterized morphologically had trapezoidal fruits mostly, upright tassel branch (4–18), non-prominent main branch and glabrous glumes, with two protruding outer ribs and 8 inner ribs, on average. Cytogenetic analysis identified 10 pairs of homologous chromosomes (2n = 20) with 26 knobs, located in the terminal region of all chromosomes. The similarity of these results with the information reported in the literature indicates that the five populations of wild relatives of maize in this region of Santa Catarina belong to the botanical species Zea luxurians. PMID:26488577

  9. A morphometric analysis of the redistribution of organelles in columella cells of horizontally-oriented roots of Zea mays

    Science.gov (United States)

    Moore, R.

    1986-01-01

    In order to determine what structural changes in graviperceptive cells are associated with onset of root gravicurvature, the redistribution of organelles in columella cells of horizontally-oriented, graviresponding roots of Zea mays has been quantified. Root gravicurvature began by 15 min after reorientation, and did not involve significant changes in the (i) volume of individual columella cells or amyloplasts, (ii) relative volume of any cellular organelle, (iii) number of amyloplasts per columella cell, or (iv) surface area of cellular location of endoplasmic reticulum. Sedimentation of amyloplasts began within 1 to 2 min after reorientation, and was characterized by an intensely staining area of cytoplasm adjacent to the sedimenting amyloplasts. By 5 min after reorientation, amyloplasts were located in the lower distal corner of columella cells, and, by 15 min after reorientation, overlaid the entire length of the lower cell wall. No consistent contact between amyloplasts and any cellular structure was detected at any stage of gravicurvature. Centrally-located nuclei initially migrated upward in columella cells of horizontally-oriented roots, after which they moved to the proximal ends of the cells by 15 min after reorientation. No significant pattern of redistribution of vacuoles, mitochondria, dictyosomes, or hyaloplasm was detected that correlated with the onset of gravicurvature. These results indicate that amyloplasts and nuclei are the only organelles whose movements correlate positively with the onset of gravicurvature by primary roots of this cultivar of Zea mays.

  10. Effect of Nitrogen Nutritional Stress on some Mineral Nutrients and Photosynthetic Apparatus of Zea mays L. and Vigna unguiculata L.

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    Akinbode Foluso OLOGUNDUDU

    2013-08-01

    Full Text Available The study investigated the responses of maize (Zea mays L. and cowpea (Vigna unguiculata L. Walp. seedlings metabolic activities and photosynthetic apparatus to nitrogen nutritional stress. Germination of seeds was done using treated sand in sixty plastic pots and the seedlings were divided into four nutrient regimes. A group of the seedlings was nutrient stressed by administering 200 ml of complete nutrient solution minus nitrogen (-N while the other groups were fed with five times (X5N and ten times (X10N the optimal concentration of nitrogen and the last regime was fed with full nutrient solution (FN. The photosynthetic parameters studied included chlorophylls ‘a’ and ‘b’ respectively; carotenes and xanthophyll while the mineral elements investigated include potassium, calcium and magnesium. The result of the growth analysis showed that nitrogen deficiency promotes an increase in the content of abscisic acid (ABA, causing stomatal closure and a reduction in photosynthesis. This explains the higher rate of leaf abscission in -N plants. A comparison of calcium ion and magnesium ion concentrations in both optimal and stressed conditions reveals that the two ions show antagonism in uptake. There is a correlation between nitrogen and magnesium accumulation as magnesium ion plays a vital role in chlorophyll biosynthesis, protein synthesis and photosynthesis. The pattern of accumulation of photosynthetic apparatus in both maize and cowpea follow a similar pattern. Chlorophyll a dictated the growth pattern of other photosynthetic apparatus in both Zea mays and Vigna unguiculata.

  11. Lipid extracted microalgal biomass residue as a fertilizer substitute for Zea mays L

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    Rahulkumar eMaurya

    2016-01-01

    Full Text Available High volumes of lipid extracted microalgal biomass residues (LMBRs are expected to be produced upon commencement of biodiesel production on a large scale, thus necessitating its value addition for sustainable development. LMBRs of Chlorella variabilis and Lyngbya majuscula were employed to substitute the nitrogen content of recommended rate of fertilizer (RRF for Zea mays L. The pot experiment comprised of 10 treatments, i.e. T1 (No fertilizer; T2 (RRF-120 N: 60 P2O5: 40 K2O kg ha-1; T3 to T6 -100, 75, 50 and 25% N through LMBR of the Chlorella sp., respectively; T7 to T10 -100, 75, 50 and 25% N through LMBR of Lyngbya sp., respectively. It was found that all LMBR substitution treatments were at par to RRF with respect to grain yield production. T10 gave the highest grain yield (65.16 g plant-1, which was closely followed by that (63.48 g plant-1 under T5. T10 also recorded the highest phosphorus and potassium contents in grains. T4 was markedly superior over control in terms of dry matter accumulation (DMA as well as carbohydrate content, which was ascribed to higher pigment content and photosynthetic activity in leaves. Even though considerably lower DMA was obtained in Lyngbya treatments, which might have been due to the presence of some toxic factors, no reduction in grain yield was apparent. The length of the tassel was significantly higher in either of the LMBRs at any substitution rates over RRF, except T6 and T7. The ascorbate peroxidase activity decreased with decreasing dose of Chlorella LMBR, while all the Lyngbya LMBR treatments recorded lower activity, which were at par with each other. Among the Chlorella treatments, only T5 recorded significantly higher values of glutathione reductase activity over RRF, while the rest were at par. There were significant increases in carbohydrate and crude fat, respectively, only in T4 and T3 over RRF, while no change was observed in crude protein due to LMBR treatments. Apparently, there was no

  12. A comparison of canopy evapotranspiration between perennial rhizomatous grasses and Zea mays

    Science.gov (United States)

    Hickman, G.; Bernacchi, C.; Dohleman, F.

    2008-12-01

    Perennial rhizomatous C4 grasses are currently considered one of the most promising vegetation types to accommodate a cellulosic feedstock based liquid fuel economy. The current focus on using these vegetation types as a source of renewable fuel has sparked numerous concerns associated with environmental impacts. Of particular interest is the impact that altering the composition of vegetation at the landscape scale would have on local and regional hydrological cycles. We hypothesize that evapotranspiration, ET, will be higher for perennial grasses relative to maize as a result higher leaf area, higher above-ground biomass and prolonged growing seasons. To test this hypothesis, a technique in which ET is estimated as the residual in the energy balance equation from measurements of net radiation and sensible and latent heat fluxes was employed. Measurements were made during the 2007 growing season for three replicate plots of the perennial rhizomatous grasses Miscanthus giganteus and Panicum virgatum, as well as for Zea mays planted at the University of Illinois South Farms. When averaged across the entire growing season, ET for M. giganteus was double relative to Z. mays, and 130% of P. virgatum ET. When compared over the periods in which all three species experienced mature and closed canopies (from day of year 200 to 250), M. giganteus still showed higher rates of ET compared with Z. mays, however, the increase was only ~15%. We conclude that ET associated with perennial alternative energy crops are higher relative to annual row crop; with most ET disparity, particularly for P. virgatum, being driven by phenology, quicker canopy closure and a prolonged growing season. Physiological rates of ET were highest for M. giganteus, followed by Z. mays, followed P. virgatum. Differences in phenology were more important than those of physiology for ET overshadowing effects from increased biomass associated with M. giganteus and/or a physiological difference between these

  13. Stable isotope biogeochemistry of seabird guano fertilization: results from growth chamber studies with maize (Zea mays.

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    Paul Szpak

    Full Text Available BACKGROUND: Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ(15N. Animal excrement is known to impact plant δ(15N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint. METHODOLOGY/PRINCIPAL FINDINGS: This paper presents isotopic (δ(13C and δ(15N and vital data for maize (Zea mays fertilized with Peruvian seabird guano under controlled conditions. The level of (15N enrichment in fertilized plants is very large, with δ(15N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ(15N values ranged between -0.3 and 5.7‰. Intraplant and temporal variability in δ(15N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ(13C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk. CONCLUSIONS/SIGNIFICANCE: The results presented in this study demonstrate the very large impact of seabird guano on maize δ(15N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs. Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level

  14. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing.

    Science.gov (United States)

    Correa-Galeote, David; Bedmar, Eulogio J; Fernández-González, Antonio J; Fernández-López, Manuel; Arone, Gregorio J

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  15. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing

    Science.gov (United States)

    Correa-Galeote, David; Bedmar, Eulogio J.; Fernández-González, Antonio J.; Fernández-López, Manuel; Arone, Gregorio J.

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  16. Potentially toxic elements in foodcrops: Triticum aestivum L., Zea mays L.

    Science.gov (United States)

    Bini, Claudio; Fontana, Silvia; Squizzato, Stefania; Minello, Fabiola; Fornasier, Flavio; Wahsha, Mohammad

    2013-04-01

    Soil is the basis of the ecosystems and of our system of food production. Crops can uptake heavy metals and potentially toxic elements from the soil and store them in the roots or translocate them to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the food chain and food consumption, result in a potential hazard for human health. In this study soils and plants (spring wheat, Triticum aestivum L. and maize, Zea mays L.) from a tannery district in North-East Italy were analyzed to determine pedological characters, soil microbial indicators and the content of some major and micro-nutrients and potentially toxic elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn, V). The soils of the area are moderately polluted; Cr is the most important inorganic contaminant, followed by Ni, Cu and V. Factor analysis evidenced that the contaminants are in part anthropogenic and in part geogenic. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd (from agriculture practices). Biological Absorption Coefficient (BAC) from soil to plant roots and Translocation factor (TF) within the plant were calculated; major nutrients (K, P, S) and some micronutrients (Cu, Zn, Mg, Mn) are easily absorbed and translocated, whilst other nutrients (Ca, Fe) and potentially toxic elements or micronutrients (Al, Cd, Cr, Ni, Pb, V) are not accumulated in the seeds of the two considered species. However, the two edible species proved differently able to absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter to the food chain and to humans. Cr concentrations in seeds and other aerial parts (stem and leaves) of the examined plants are higher than the values found for the same species and for other cereals grown on unpolluted soils. Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources

  17. PERSPECTIVAS INFANTILES SOBRE LA TERRITORIALIDAD

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    NOELIA ENRIZ

    2009-12-01

    Full Text Available In this paper we propose a different approach to children's ideas about the geographical area in the particular context of the Mbyá Guarani population, from Misiones (Argentine. The territorial fragility, that is exposed to the indigenous people in Argentina aremanifested daily in several areas. Mbyá population, has been crossed by the boundaries of national states of Paraguay, Brazil and Argentina. The sedentary and enclosures land processes in different states, have prompted changes in the logic of subsistence, housing and community organization. In Misiones province case, bureaucratic accreditation of land titles is postponed, the state is not committed to the realization of this right.RESUMEN: En este trabajo nos proponemos un acercamiento a las diversas ideas infantiles sobre el territorio habitado, en el contexto particular de la población mbyá guaraní de Misiones. La fragilidad territorialidad a la que es expuesta la población indígena en Argentina se manifiestan cotidianamente en diversas áreas. La población mbyá, ha sido surcada por los límites de los estados nacionales de Paraguay, Brasil y Argentina. La sedentarización y los cercamientos de tierras en los diferentes estados, han impulsado transformaciones de las lógicas de subsistencia, de habitación y organización comunitaria. En el caso de la provincia de Misiones la acreditación burocrática de los títulos de tierras se encuentra aplazada, el estado no se compromete con la concreción de este derecho.

  18. Consideraciones preliminares sobre la credibilidad

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    Fernando Verdugo

    2004-01-01

    Full Text Available A modo de introducción al Seminario Interno de Profesores de la Facultad de Teología de la PUC, el autor recuerda, en primer lugar, lo que suele entenderse por "credibilidad" y, también, algunos de los criterios generales por los cuales algo o alguien adquiere la calidad de creíble (el que sea razonable, relevante o significativo, capaz de producir gozo estético, etc.. Luego, en la parte más extensa, el autor vuelve a llamar la atención sobre la necesidad de atender a los condicionamientos culturales de la fe cristiana. La fe, al igual que toda experiencia humana, está culturalmente mediada. Tomar conciencia de ese hecho y asumir las consecuencias metodológicas es indispensable para una teología que quiere poner atención a los desafíos actuales y contribuir así a la credibilidad del cristianismoThis article reprints the introductory session to the internal seminar of lecturers from the Faculty of Theology of the UC. In the first place, the author sums up what is usually understood by `credibility' and the general criteria through which something or someone gains credibility (being reasonable, relevant or significant, capable of producing aesthetic pleasure. Then the author deals at length with the need to take notice of the cultural conditionings of the Christian faith. The faith, the same as any other human experience, is culturally mediated. It is crucial for theology to become aware of this fact and come to terms with its methodological consequences, if it wants to face current challenges and so contribute to the credibility of Christianity

  19. Complete Genome Sequence of Spiroplasma kunkelii Strain CR2-3x, Causal Agent of Corn Stunt Disease in Zea mays L.

    Science.gov (United States)

    Davis, Robert E; Shao, Jonathan; Dally, Ellen L; Zhao, Yan; Gasparich, Gail E; Gaynor, Brady J; Athey, John C; Harrison, Nigel A; Donofrio, Nicole

    2015-01-01

    Spiroplasma kunkelii causes corn stunt disease of Zea mays L. in the Americas. Here, we report the nucleotide sequence of the 1,463,926-bp circular chromosome and four plasmids of strain CR2-3x. This information will facilitate studies of Spiroplasma pathogenicity and evolutionary adaptations to transkingdom parasitism in plants and insect vectors. PMID:26494665

  20. The Effect of Morphaction on the Kinetics of Indol-3yl-Acetic Acid-2-14C Transport in Zea Mays L. Coleoptile Segments

    DEFF Research Database (Denmark)

    Naqvi, S. M.

    1972-01-01

    This paper elucidates the effects of chloroflurenol (morphactin, IT 3456) treatment on the kinetics of 14C-IAA transport through Zea mays L. (cv. Orla-266) coleoptile segments. Maximum inhibition of transport was achieved when chloroflurenol remained in contact with the tissue segments for at least...

  1. Dynamics of phosphorus fractions in the rhizosphere of fababean (Phaseolus vulgaris L.) and maize (Zea mays L.) grown in calcareous and acid soils

    NARCIS (Netherlands)

    Li, G.; Li, Haigang; Leffelaar, P.A.; Shen, J.; Zhang, F.

    2015-01-01

    The dynamics of soil phosphorus (P) fractions were investigated, in the rhizosphere of fababean (Vicia faba L.) and maize (Zea mays L.) grown in calcareous and acid soils. Plants were grown in a mini-rhizotron with a thin (3 mm) soil layer, which was in contact with the root-mat, and considered as r

  2. Estela Restrepo Zea. El Hospital San Juan de Dios 1635-1895: una historia de la enfermedad, pobreza y muerte en Bogotá

    Directory of Open Access Journals (Sweden)

    María Angélica Ospina Martínez

    2012-09-01

    Full Text Available [...] Este libro de Estela Restrepo Zea, producto de su tesis doctoral, es una obra que traza, con gran minucia y rigurosidad,el devenir del Hospital San Juan de Dios en Bogotá, desde su creación, en el siglo XVII, hasta finales del siglo XIX. [...

  3. Estimation of long-terminal repeat element content in the Helicoverpa zea genome from next generation sequencing of reduced representation bacterial artificial chromosome (BAC) pools

    Science.gov (United States)

    The lepidopteran pest insect, Helicoverpa zea, feeds on cultivated corn and cotton crops in North America where control remains challenging due to evolution of resistance to chemical and transgenic insecticidal toxins, yet few genomic resources are available for this species. A bacterial artificial...

  4. Effects of water stress on the photosynthetic assimilation and distribution of 14C-photosynthate in maize (Zea mays L.) and bean (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    The relationship between photosynthesis and distribution of 14C-photosinthate as affected by water stress was evaluated. Corn (Zea mays L.) during the grain filling period and bean (Phaseolus vulgaris L.) during flowering, representing a C-4 and a C-3 photosynthetic type, respectively, were studied. (M.A.C.)

  5. The role of 2,4-D and auxin-binding proteins during the induction of embryogenic and non-embryogenic callus in Zea mays (L.).

    NARCIS (Netherlands)

    Bronsema, F.

    1998-01-01

    This thesis deals with the influence of the growth regulator 2,4-dichlorophenoxyacetic acid (2,4-D) on the induction of callus in cultured immature embryos of Zea mays (L). In maize, two types of embryogenic callus can be induced in immature zygotic embryos.Type I callus, which is compact in appeara

  6. Maternal and paternal transmission to offspring of B-chromosomes of Zea mays L. in the alien genetic background of Avena sativa L.

    Science.gov (United States)

    B-chromosomes are supernumerary dispensable chromosomes with highly host-specific organization, behavior, and mode of inheritance described in hundreds of animal, fungal, and plant species. We transferred native B chromosomes of maize (Zea mays L. ssp. mays cv. Black Mexican Sweet) to oats (Avena sa...

  7. Evaluation of the Allelopathic Influence of Selected Multi-purpose Tree Species on Maize (Zea mays) under a Simulated Field Condition

    OpenAIRE

    Adeorike, V.; Ogburia, MN; Anegbeh, P.

    2001-01-01

    Germination and growth response of maize (Zea mays) that was periodically watered with 200 ml of leaf leachates of three selected multipurpose tree species (MPTs) - Inga edulis, Anthonatha macrophylla and Dactyladenia barterii were evaluated under a simulated field condition to determine their allolepathic characteristics and suitability for alley cropping. There was a significant (P

  8. Reducción del colesterol y aumento de la capacidad antioxidante por el consumo crónico de maíz morado (Zea mays L en ratas hipercolesterolémicas

    Directory of Open Access Journals (Sweden)

    Jorge Arroyo

    2007-04-01

    Full Text Available Objetivos: Determinar la actividad hipocolesterolémica y antioxidante del consumo crónico del extracto hidroalcohólico atomizado del maíz morado (Zea mays L en ratas hipercolesterolémicas. Materiales y métodos: Se utilizaron cinco grupos de seis ratas Holtzmann cada uno, uno sin hipercolesterolemia (control negativo, y cuatro con hipercolesterolemia inducida por consumo de colesterol puro vía oral durante 60 días: control positivo y tres para las dosis de 250, 500 y 1000 mg/kg, respectivamente. En el día 60 se determinaron los niveles séricos de colesterol total, triglicéridos y colesterol HDL (mg/dL, así como de malondialdehido (mmol/L para determinar la actividad antioxidante. Se comparó la diferencias de medias con ANOVA y test de Tukey. Resultados: Se observó una disminución del colesterol total en las ratas hipercolesterolémicas que consumieron dosis de 250 y 500 mg/kg en relación con el grupo control positivo (reducción de 21,5 y 11,2% respectivamente, p<0,01. No se observaron diferencias significativas sobre los niveles de triglicéridos y colesterol HDL. A mayor dosis se maíz morado se encontró una mayor reducción de radicales libres, con la dosis de 1000 mg/kg se redujo en 56,4% los niveles de malondialdehido (p< 0,01. Conclusiones: En condiciones experimentales, el consumo crónico del extracto hidroalcohólico atomizado de maíz morado disminuye los niveles de colesterol total y aumenta la capacidad antioxidante.

  9. Controle de plantas daninhas na cultura do milho (Zea mays L. por meio de herbicidas Weed control in maize (Zea mays L. with herbicides

    Directory of Open Access Journals (Sweden)

    C. A. L. dos Santos

    1979-12-01

    Full Text Available Com o objetivo de se verificar a ação do butylate, aplicado isoladamente e em mistura com atrazine, no controle de plantas daninhas da cultura do milho, foi instalado um experimento de campo em solo fino areno-argiloso. Foram utilizados os seguintes tratamentos: butylate a 2,80; 3,60 e 4,32 kg/ha (p.p.i.; butylate + atrazine a 3,24 + 0,80; 3,24 + 1,20 e 3,60 + 0,96 kg/ha (p.p.i.; atrazine a 3,00 kg/ha e atrazine + metolachlor a 1,40 + 2,10 kg/ha, ambos aplicados em pré-emergência e empregados como herbicidas padrão para a cultura. As plantas daninhas encontradas foram: tiririca - Cyperus rotundus L., carurú comum - .:maranthus viridis L., capim de colchão - Digitaria sanguinalis (L. Scop. e capim pé-de-galinha Eleusine indica (L. Gaertn. Butylate nas três doses apresentou-se bem contra C. rotundus e E. indica; nas doses de 3,60 e 4,32 kg foram obtidos bons resultados sobre D. sanguinalis. Butylate + atrazine controlou, nas três doses, todas as espécies incidentes, o mesmo ocorrendo com a mistura atrazine + metolachlor. Atrazine foi mais eficiente para A. viridis e E. indica. Nas condições em que foi conduzido o experimento nenhum dos herbicidas foi prejudicial para a cultura.Butylate at 2.80; 3.60 and 4.32 kg/ha and butylate + atrazine at. 3.24 + 0.80; 3.24 + 1.20 and 3.60 + 0.96 kg, were applied in preplant incorporated; atrazine at 3.00 kg and atrazine + metolachlor at 1.40 + 2.10 kg were applied in preemergence on corn. The weeds were represented by Cyperus rotundus L., Amaranthus viridis L., Digitaria sanguinalis (L. Scop. and Eleusine indica (L. Gaertn. Butylate + atrazine, in all rates, atrazine + metolachlor and atrazine gave good control of the weeds in general. Butylate, in the three rates, controlled C. rotundus and E. indica; at 3.60 and 4.32 kg/ha controlled well D. sanguinalis. The herbicides did not cause injuries to the crop.

  10. Substituição do milho Zea mays por milheto Pennisetum americanum em rações para alevinos de carpa-capim Ctenopharyngodon idella - DOI: 10.4025/actascibiolsci.v27i1.1365 Replacement of corn Zea mays by millet Pennisetum americanum in grass carp Ctenopharyngodon idella fingerlings diets - DOI: 10.4025/actascibiolsci.v27i1.1365

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Figueiredo Lacerda

    2005-03-01

    Full Text Available O presente experimento com duração de 45 dias foi conduzido com o objetivo de avaliar o efeito da substituição do milho Zea mays (0,00%; 33,00%; 66,67% e 100,00% pelo milheto Pennisetum americanum, em rações sobre o desempenho de alevinos de carpa-capim Ctenopharyngodon idella. Foram utilizados 112 alevinos de carpa-capim (0,75 g, distribuídos em 16 tanques-rede (160 L, em um delineamento em blocos casualizados, com 4 tratamentos e 4 repetições. Cada bloco correspondeu a uma caixa de fibrocimento (1.000 L com 4 tanques-rede, onde cada um deles contendo 7 alevinos foi considerado uma unidade experimental. As variáveis avaliadas foram peso final médio, ganho de peso, comprimento final médio, conversão alimentar aparente, fator de condição e taxa de sobrevivência. Não foram observados efeitos da utilização do milheto sobre os parâmetros de desempenho produtivo analisados (p > 0,01. Os valores médios de temperatura, pH, condutividade elétrica e oxigênio dissolvido durante o período experimental foram de 24,5 ± 1,39ºC; 7,51 ± 0,32; 0,16 ± 0,01 µS/cm e 6,04 ± 1,28 mg/L, respectivamente. Conclui-se que o milheto pode ser incluído na ração para alevinos de C. idella em até 33,7%, substituindo totalmente o milho sem afetar o desempenho dos animaisThe present experiment was carried out to evaluate the effects of the replacement of corn Zea. Mays (0.00%; 33.00%; 66.67% e 100.00% by millet P. americanum in grass carp Ctenopharyngodon idella fingerlings diets, during a 45 days period. One hundred and twelve carp grass fingerlings (0.75 g were used, distributed in 16 net ponds (160 L, in randomized blocks with four treatments and four replicates. Each block corresponded to one fiber cement tank (1000 L with four net ponds. Each net pond containing seven grass carp fingerlings was considered one experimental unit. The variables evaluated were: mean weight, mean weight gain, mean length, outward feed conversion, condition

  11. DISERTACIÓN SOBRE JUSTICIA Y EQUIDAD

    Directory of Open Access Journals (Sweden)

    Sayuri P. Tamura M.

    2001-01-01

    Full Text Available «Disertación sobre equidad y justicia» es básicamente una respuesta a una inquietud en particular que yo tenía sobre las distintas posiciones que existen sobre estos dos temas y cómo definir cuál es la más acertada. Hice una descripción del punto de vista de Amartya Sen –la violación de los derechos sobre la propiedad privada es justificable si evitan las hambrunas2– frente al de Robert Nozick –la propiedad privada es un derecho fundamental y como tal debe ser respetado3–, sin embargo, aunque ambos enfoques son totalmente contrarios tienen mucho sentido, por lo cual es bastante difícil decidirse por uno en particular. Fue de esta forma, enfrentando sus opiniones, que yo logré desarrollar una posición frente a estas dos perspectivas, y así dar mi opinión al DISERTACIÓN SOBRE JUSTICIA Y EQUIDAD SAYURI P. TAMURA M. Estudiante de Economía y Negocios Internacionales de la Universidad ICESI. respecto. Al final, llegué a una conclusión, que aunque no es la más original y tampoco es la única, tiene mucho sentido y seguramente de ser posible, la situación del país podría cambiar para bien.

  12. PENGARUH PENAMBAHAN PUPUK NPK TERHADAP PRODUKSI BEBERAPA AKSESI TANAMAN JAGUNG (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Danny Pratikta

    2013-11-01

    Split Plot dengan tiga ulangan. Petak utama adalah Pupuk NPK (200, 300, 400 kg NPK ha-1 dan sub-plot adalah aksesi jagung (V1 = Srikandi Kuning x Manado Merah, V2 = Bisma x Srikandi Kuning, V3 = Srikandi Kuning x Bisma, dan V4 = Bisma x Manado Merah. Hasil percobaan dianalisis dengan menggunakan analisis varian (ANOVA dan Duncan Multiple Range Test (DMRT pada taraf α 5% (Hanafiah, 2005 dengan menggunakan program excel. Parameter pengamatan meliputi tinggi tanaman, jumlah daun atas dan dibawah tongkol jagung, umur berbunga jantan, umur berbungan betina, umur masak fisiologis, berat tongkol per petak (kg, berat pipilan per petak (kg, berat tongkol per tanaman (g, panjang tongkol isi (cm, lingkar tongkol (cm, berat 100 biji per tanaman (g, dan kandungan protein biji jagung (mg g-1. Hasil penelitian menunjukkan bahwa tidak ada perbedaan yang nyata antar perlakuan yang dicobakan pada parameter yang diamati. Perlakuan penambahan pupuk NPK tidak menunjukkan pengaruh yang nyata pada semua parameter. Berdasarkan pemilihan karakter, semua aksesi terpilih lebih tinggi dibanding varietas Bisma. Kandungan protein rata-rata aksesi yang diuji yaitu 11,14 ; 10,25 ; 10,95 ; dan 10,10 mg g-1 masing-masing untuk V1, V2, V3, dan V4. Kata Kunci: Pupuk NPK; Aksesi Jagung; Produksi How to citate: Pratikta D, S Hartatik, KA Wijaya. 2013. Pengaruh penambahan pupuk NPK terhadap produksi beberapa aksesi tanaman jagung (Zea mays L.. Berkala Ilmiah Pertanian 1(2: 19-21.

  13. Processes of ammonia air–surface exchange in a fertilized Zea mays canopy

    Directory of Open Access Journals (Sweden)

    E. Nemitz

    2013-02-01

    Full Text Available Recent incorporation of coupled soil biogeochemical and bi-directional NH3 air–surface exchange algorithms into regional air quality models holds promise for further reducing uncertainty in estimates of NH3 emissions from fertilized soils. While this represents a significant advancement over previous approaches, the evaluation and improvement of such modeling systems for fertilized crops requires process-level field measurements over extended periods of time that capture the range of soil, vegetation, and atmospheric conditions that drive short-term (i.e., post-fertilization and total growing season NH3 fluxes. This study examines the processes of NH3 air–surface exchange in a fertilized corn (Zea mays canopy over the majority of a growing season to characterize soil emissions after fertilization and investigate soil–canopy interactions. Micrometeorological flux measurements above the canopy, measurements of soil, leaf apoplast and dew/guttation chemistry, and a combination of in-canopy measurements, inverse source/sink, and resistance modeling were employed. Over a period of approximately 10 weeks following fertilization, daily mean and median net canopy-scale fluxes yielded cumulative total N losses of 8.4% and 6.1%, respectively, of the 134 kg N ha−1 surface applied to the soil as urea ammonium nitrate (UAN. During the first month after fertilization, daily mean emission fluxes were positively correlated with soil temperature and soil volumetric water. Diurnally, maximum hourly average fluxes of ≈ 700 ng N m−2 s−1 occurred near mid-day, coincident with the daily maximum in friction velocity. Net emission was still observed 5 to 10 weeks after fertilization, although mid-day peak fluxes had declined to ≈ 125 ng N m−2 s−1. A key finding of the surface chemistry measurements was the observation of high pH (7.0–8.5 in leaf dew/guttation, which reduced the ability of the canopy to recapture soil emissions during wet periods

  14. Processes of ammonia air-surface exchange in a fertilized Zea mays canopy

    Directory of Open Access Journals (Sweden)

    E. Nemitz

    2012-06-01

    Full Text Available Recent incorporation of coupled soil biogeochemical and bi-directional NH3 air-surface exchange algorithms into regional air quality models holds promise for further reducing uncertainty in estimates of NH3 emissions from fertilized soils. While this represents a significant advancement over previous approaches, the evaluation and improvement of such modeling systems for fertilized crops requires process level field measurements over extended periods of time that capture the range of soil, vegetation, and atmospheric conditions that drive short term (i.e., post fertilization and total growing seasonNH3 fluxes. This study examines the processes of NH3 air-surface exchange in a fertilized corn (Zea mays canopy over the majority of a growing season to characterize soil emissions after fertilization and investigate soil-canopy interactions. Micrometeorological flux measurements above the canopy, measurements of soil, leaf apoplast and dew/guttation chemistry, and a combination of in-canopy measurements, inverse source/sink, and resistance modeling were employed. Over a period of approximately 10 weeks following fertilization, daily mean and median net canopy-scale fluxes yielded cumulative total N losses of 8.4% and 6.1%, respectively, of the 134 kg N ha−1 surface applied to the soil as urea ammonium nitrate (UAN. During the first month after fertilization, daily mean emission fluxes were positively correlated with soil temperature and soil volumetric water. Diurnally, maximum hourly average fluxes of ≈700 ng N m−2 s−1 occurred near mid-day, coincident with the daily maximum in friction velocity. Net emission was still observed 5 to 10 weeks after fertilization, although mid-day peak fluxes had declined to ≈125 ng N m−2 s−1 A key finding of the surface chemistry measurements was the observation of high pH (7.0 – 8.5 in leaf dew/guttation, which reduced the ability of the canopy to recapture soil emissions during wet periods. In

  15. Development of genetic and molecular indices for drought tolerance in some inbred and hybrids of maize (Zea mays L.)

    International Nuclear Information System (INIS)

    From eighteen zea mays inbred lines, two were chosen as drought tolerant and drought sensitive genotypes (G621W and G603W, respectively). They were evaluated along with their F1 and F2 for their relative drought tolerance for some yield traits. The physiological markers cations (Na, K, Ca and Mg) and their ratios (K/Na, Ca/K and Ca/Mg) showed differential association with drought tolerance was observed.SDS-protein profiles indicated the presence of two bands in the tolerant group associated with drought tolerance. Western blotting analysis didn't give polymorphism patterns such as esterase, peroxidase and acid phosphatase showed differential responses with respect to drought tolerance

  16. Rate and timing effect of CGA-136872 for postemergence Johnsongrass Sorghum halepense L. control in corn Zea mays L

    Directory of Open Access Journals (Sweden)

    Ngouajio, M.

    1992-01-01

    Full Text Available Field experiments were conducted in Virginia in 1988-89 to evaluate CGA-136872 activity for postemergence control of johnsongrass Sorghum halepense (L. Pers in field corn Zea mays L. grown under conventional tillage system. CGA-136872activity on johnsongrass was dependent on the application timing. Applications at three weeks after planting (WAP were more effective than early or late applications. Five weeks after treatment, these applications provided 90 % control of the weed with 30 and 40 g ai (active ingredient/ha of the herbicide. Early applications resulted in less than 70 % control at with all rates due to regrowth from rhizomes. Sequential applications with low rates resulted in more activity than a single high rate applied early or late in the season. Corn yield was improved with applications at three weeks after planting and sequential applications, compared to early or late applications. Johnsongrass competition with corn in untreated plots resulted in very low yield (174 kg/ha.

  17. Activity of Acetolactate Synthase from Maize (Zea mays L. ) as Influenced by Chlorsulfuron and Tribenuron-methyl

    Institute of Scientific and Technical Information of China (English)

    FAN Zhi-jin; CHEN Jun-peng; HU Ji-ye; QIAN Chuan-fan; LI Zheng-ming

    2003-01-01

    Study on relative sensitivity of maize (Zea mays L. ) Nongda108 and Nongda3138 to sulfonylurea herbicide chlorsulfuron and tribenuron-methyl using maize taproot length by sand bioassy indicated that, Nongda3138 had higher tolerance to chlorsulfuron and tribenuron-methyl than Nongda108 did. Chlorsulfuron had stronger growth inhibition to maize Nongda108 and Nongda3138 than tribenuron-methyl did. Study on target enzyme of sulfonylurea herbicide acetolactate synthase (ALS) showed that, chlorsulfuron and tribenuron-methyl inhibited ALS in vitro strongly, and non-competitively. In the same concentration of inhibitors,chlorsuifuron had stronger ALS activity inhibition than tribenuron-methyl did. Lower level of chlorsulfuron and tribenuron-methyl has no ALS activity inhibition in vivo, the ALS inhibition only occurred in the condition of high concentration of chlorsulfuron and tribenuron-methyl in vivo.

  18. Influence of electrical fields and asymmetric application of mucilage on curvature of primary roots of Zea mays

    Science.gov (United States)

    Marcum, H.; Moore, R.

    1990-01-01

    Primary roots of Zea mays cv. Yellow Dent growing in an electric field curve towards the anode. Roots treated with EDTA and growing in electric field do not curve. When root cap mucilage is applied asymmetrically to tips of vertically-oriented roots, the roots curve toward the mucilage. Roots treated with EDTA curve toward the side receiving mucilage and toward blocks containing 10 mM CaCl2, but not toward "empty" agar blocks or the cut surfaces of severed root tips. These results suggest that 1) free calcium (Ca) is necessary for root electrotropism, 2) mucilage contains effector(s) that induce gravitropiclike curvature, and 3) mucilage can replace gravitropic effectors chelated by EDTA. These results are consistent with the hypothesis that the downward movement of gravitropic effectors to the lower sides of tips of horizontally-oriented roots occurs at least partially in the apoplast.

  19. Callose deposition during gravitropism of Zea mays and Pisum sativum and its inhibition by 2-deoxy-D-glucose

    Science.gov (United States)

    Jaffe, M. J.; Leopold, A. C.

    1984-01-01

    In etiolated corn (Zea mays L.) and etiolated pea (Pisum sativum L.) seedlings, a gravitropic stimulation induces the deposition of callose. In the corn coleoptiles this occurs within 5 min of gravity stimulation, and prior to the beginning of curvature. Both gravitropic curvature and callose deposition reach their maxima by 12 h. Within the first 2 h more callose is deposited on the upper (concave) side, but after 2-3 h, this deposition pattern is reversed. An inhibitor of protein glycosylation, 2-deoxy-D-glucose (DDG), inhibits callose production and considerably retards gravitropic bending in both species of plants. Mannose can relieve the inhibition of gravitropic bending by DDG. The pea mutant "Ageotropum", which does not respond to gravity when etiolated, also fails to produce callose in response to a gravitic stimulus. These correlations indicate that callose deposition may be a biochemical component of gravitropism in plant shoots.

  20. Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

    Science.gov (United States)

    Chisnell, J. R.

    1984-01-01

    Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

  1. Rastros: dizendo sobre os fazeres/dizeres

    OpenAIRE

    MELLO MARISOL BARENCO CORRÊA DE

    2001-01-01

    Com vistas ao aclaramento de noções erroneamente herdadas do contexto social e histórico da cultura moderna ocidental, que teve/tem como um de seus projetos o "apagamento" do sujeito, ou o distanciamento entre os sujeitos e suas formas de fazer, dizer, pensar, este artigo pretende contribuir com elementos para a construção de um outro paradigma nas ciências humanas. Trata-se de um relato sobre o processo de construção de nossa própria pesquisa, articulado à reflexão sobre as diversas formas d...

  2. Sobre la esclavitud: libro de artista

    OpenAIRE

    MACHADO JIMÉNEZ, ALBERTO

    2015-01-01

    Sobre la esclavitud es un libro de artista, donde encontraremos imágenes acompañadas de breves frases que hacen referencia al tema propuesto en cada ilustración para que así se pueda comprender mejor la intención de este trabajo, reflexionar sobre la manera que tenemos de ver las cosas, en este caso, con respecto a la esclavitud. Dar a conocer distintas formas de ser esclavo en este sistema sería uno de los objetivos principales. Hacer litografías, dibujos con el uso de acua...

  3. Consideraciones sobre diferentes procesos productivos y sus consecuencias sobre el medio ambiente

    OpenAIRE

    Caridad Ramos Alvariño

    2004-01-01

    En el presente trabajo se exponen algunas consideraciones sobre diferentes procesos productivos y sus consecuencias sobre el medio ambiente. La disminución del impacto negativo de algunas producciones sobre el medio ambiente es favorable, pero el problema va más allá y de lo que se trata es de la necesidad de una transformación sostenible de las producciones que puedan conducir a una vida agradable y una naturaleza conservada entre otras muchas cuestiones que agobian hoy al mundo. La solución...

  4. Respiration and Energy Turnover During the Seedling Development of Triticum aestivum L., Zea mays L., Helianthus annuus L., and Phaseolus vulgaris L.

    Science.gov (United States)

    Bolhàr-Nordenkampf, H R; Zahrl, J

    1984-08-01

    Seedling length, CO(2) output, dry weight and energy content of the seeds and seedling organs of Triticum, Zea, Helianthus and Phaseolus were determined in order to study the efficiency of storage substance utilization and energy turnover during seedling development up to 108 h. The respiration rate is lower in the large seeds of Zea and Phaseolus (2.2 and 2.0 mgCO(2)·gDW(-1)·h(-1)) than in the small seeds of Triticum and Helianthus (3.1 and 4.2 mgCO(2)·gDW(-1)·h(-1)). CO(2) output during the synthesis of seedling organs reaches a maximum value in Triticum, Zea and Helianthus after 36 h (1.0, 1.7 and 1.3 gCO(2)·gDW(n)(-1), resp.) and in Phaseolus after 60 h (3.0 gCO(2)·gDW(n)(-1)). This high CO(2) evolution is caused by the lag phase of growth at the beginning of germination, as indicated in the RGR course. The loss of mobilized storage substances caused by CO(2) evolution amounts to 46% in Phaseolus and is less (av. 30%) in the other seeds. The energy loss in relation to the energy of the ungerminated seed is relatively high in the small and energy-rich seeds of Triticum (19%) and Helianthus (21 %) compared with the large seeds of Zea (8 %) and Phaseolus (13 %). The efficiency of energy utilization corresponding to the energy stored in the newly formed seedling organs is low in Helianthus (40%) and Phaseolus (43%) and relatively high in Triticum (55%) and Zea (6 %). The calorific equivalent of the CO(2) amount evolved differs widely (11 to 24 kJ·gCO(2)(-1)). With the exception of Zea these values are much higher than the calorific equivalent of the dry weight loss. The latter may be explained by energy losses without CO(2) evolution, as well as by CO(2) refixation by PEPC and by energy dissipation in the maintenance metabolism. PMID:23194792

  5. Las fuentes cristianas sobre Jesús

    Directory of Open Access Journals (Sweden)

    Melero Martínez, J.M.

    2010-01-01

    Full Text Available El artículo es una presentación de las fuentes históricas sobre Jesús de Nazaret: fuentes sinópticas, fuente Q, fuentes afines a la gnosis, fragmentos de evangelio con material sinóptico o joánico, evangelios judeocristianos y otras fuentes.

  6. Sobre un sistema no lineal de epidemias

    OpenAIRE

    Ortega S., Luis

    2012-01-01

    Un modelo sobre epidemias que describe la población infectada y la población susceptible de ser infectada en el cual se toma en consideraci6n el efecto de difusión es el siguiente: [Formula Matemática].

  7. Puente pretensado sobre el Guadarrama. Villalba

    Directory of Open Access Journals (Sweden)

    Páez, A.

    1958-12-01

    Full Text Available En este artículo se describe y comenta la solución dada al puente de hormigón pretensado sobre el río Guadarrama, primero de los construidos mediante dovelas prefabricadas y solidarizadas después, mediante el pretensado de la armadura longitudinal.

  8. Sobre o natural e o actor

    OpenAIRE

    Tavares, Margarida

    2010-01-01

    Neste artigo, procura-se reflectir sobre o conceito de natural quando aplicado ao trabalho do actor. Parte-se de quatro relevantes textos da dramaturgia ocidental, a saber: Hamlet, de Shakespeare; Crítica da ‘Escola das mulheres’ e O improviso de Versalhes, de Molière; e O teatro cómico, de Goldoni.

  9. Differences on Pb accumulation among plant tissues of 25 varieties of maize (Zea mays)

    Institute of Scientific and Technical Information of China (English)

    DAI Quanlin; YUAN Jiangang; FANG Wei; YANG Zhongyi

    2007-01-01

    Pollution of agricultural land by heavy metals has imposed an increasingly serious risk to environmental and human health in recent years.Heavy metal pollutants may enter the human food chain through agricultural products and groundwater from the polluted soils.Progress has been made in the past decade on phytoremediation,a safe and inexpensive approach to remove contaminants from soil and water using plants.However,in most cases,agricultural land in China cannot afford to grow phytoremediator plants instead of growing crops due to food supply for the great population.Therefore,new and effective methods to decrease the risk of heavy metal pollution in crops and to clean the contaminated soils are urgently needed.If we can find crop germplasms (including species and varieties) that accumulate heavy metals in their edible parts,such as the leaves of vegetables or grains of cereals,at a level low enough for safe consumption,then we can grow these selected species or varieties in the lands contaminated or potentially contaminated by heavy metals.If we can find crop germplasms that take in low concentrations of heavy metals in their edible parts and high content of the metals in their inedible parts,then we can use these selected species or varieties for soil remediation.In this study,the feasibility of the method is assessed by analyzing Pb concentrations in edible and inedible parts of 25 varieties of maize (Zea mays) grown in Pb-contaminated soils.The soil concentrations of Pb were 595.55 mg/kg in the high Pb exposed treatment and 195.55 mg/kg in the control.The results showed that the Pb concentrations in different tissues were in the order of root > shoot ≌ leaf> grain.Compared with the control,the Pb concentrations in root,shoot and leaf were greatly increased under the high Pb exposed condition,while the increments of Pb concentration in grain were relatively lower.Under the high Pb exposure,the grain Pb concentrations of 12 varieties exceeded the maximal

  10. Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

    Science.gov (United States)

    Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

    2016-10-01

    The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry. PMID:27391049

  11. Effect of compost and slow-release fertilizers addition on soil biochemistry and yield of maize (Zea mays L.) in Oaxaca, Mexico

    OpenAIRE

    Angélica Bautista-Cruz; Gricel Cruz Domínguez; María de las Nieves Rodríguez Mendoza; Rafael Pérez Pacheco; Celerino Robles

    2014-01-01

    The effect of Bokashi (B, a fermented compost), slow-release fertilizers (SRFs) and their combined application on mycorrhizal colonization (MC), soil invertase, cellulase, acid (AcP) and alkaline (AlP) phosphatases activities and maize ( Zea mays L.) yield was investigated in terrace (TS) and valley (VS) soils in Oaxaca, Mexico. A complete randomized design, seven fertilizer treatments and four replications were used: unamended control (C); conventional fertilization (90-46-00 NPK...

  12. An improved methodology for the recovery of Zea mays and other large crop pollen, with implications for environmental archaeology in the Neotropics

    OpenAIRE

    Whitney, Bronwen S.; Rushton, Elizabeth A.C.; Carson, John F.; Iriarte, José; Mayle, Francis E

    2012-01-01

    We present a simple sieving methodology to aid the recovery of large cultigen pollen grains, such as maize (Zea mays L.), manioc (Manihot esculenta Crantz), and sweet potato (Ipomoea batatas L.), among others, for the detection of food production using fossil pollen analysis of lake sediments in the tropical Americas. The new methodology was tested on three large study lakes located next to known and/or excavated pre-Columbian archaeological sites in South and Central America. Five paired sam...

  13. Ketersediaan Hara-P Dan Respon Tanaman Jagung (Zea Mays L) Pada Tanah Ultisol Tambunan-A Akibat Pemberian Guano Dan Mikroorganisme Pelarut Fosfat (MPF)

    OpenAIRE

    Wahid Ramadan S. Nasution

    2009-01-01

    Ketersediaan Hara P dan Respon Tanaman Jagung (Zea mays L) pada Tanah Ultisol Tambunan A akibat Pemberian Guano dan Mikroorganisme Pelarut Fosfat (MPF). Penelitian ini dilaksanakan di Laboratorium Biologi Tanah, Laboratorium Sentral, Rumah Kaca Fakultas Pertanian, USU Medan dan bulan Juni sampai September 2005. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian guano dan mikroorganisme pelarut Fosfat (MPF) terhadap ketersediaan hara P dan respon tanaman jagung pada ultisol Tambunan ...

  14. Purple Corn (Zea mays L.) Phenolic Compounds Profile and Its Assessment as an Agent Against Oxidative Stress in Isolated Mouse Organs

    OpenAIRE

    Ramos-Escudero, Fernando; Muñoz, Ana María; Alvarado-Ortíz, Carlos; Alvarado, Ángel; Yáñez, Jaime A.

    2012-01-01

    This study was designed to determine the contents of total polyphenols, flavonoids, flavonols, flavanols, and anthocyanins of purple corn (Zea mays L.) extracts obtained with different methanol:water concentrations, acidified with 1% HCl (1 N). Another objective was to determine the antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and deoxyribose assay, individual phenolic comp...

  15. Identification of a G protein-coupled receptor for pheromone biosynthesis activating neuropeptide from pheromone glands of the moth Helicoverpa zea

    OpenAIRE

    Choi, Man-Yeon; Fuerst, Emily-Jean; Rafaeli, Ada; Jurenka, Russell

    2003-01-01

    Pheromone biosynthesis-activating neuropeptide (PBAN), a peptide produced by the subesophageal ganglion, is used by a variety of moths to regulate pheromone production. PBAN acts directly on pheromone gland cells by using calcium and cAMP as second messengers. We have identified a gene encoding a G protein-coupled receptor (GPCR) from pheromone glands of the female moth Helicoverpa zea. The gene was identified based on sequence identity to a group of GPCRs from Drosoph...

  16. Allelopathic Effect of Lantana camara L. Leaf Powder on Germination and Growth Behaviour of Maize, Zea mays Linn. and Wheat, Triticum turgidum Linn. Cultivars

    OpenAIRE

    Abiyu Enyew; Nagappan Raja

    2015-01-01

    Aim of the present study was to evaluate allelopathic effect of Lantana camara leaf powder on germination and growth behaviour of Zea mays and Triticum turgidum. The pot culture experiments were conducted at Botany laboratory, Tewodros campus, University of Gondar, Ethiopia from November 2012 to April 2013. The experimental design was Completely Randomized Block Design (CRBD) with three treatments and one control. The soil without adding L. camara leaf powder was considered as control (T0) an...

  17. Ketersediaan Hara-P dan Respon Tanaman Jagung (Zea maysL)pada Tanah Ultisol Tambunan A Akibat Pemberian Guano dan Mikroorganisme Pelarut Fosfat (MPF)

    OpenAIRE

    S, Wahid Ramadan

    2012-01-01

    Availability of P Nutrition and Respons of Maize (Zea mays L) on Ultisol soil for the Application of Guano and Phophate Solvent Microorganism. This research was conducted at soil biology laboratory, central laboratory and greenhouse of Agricultural faculty of USU Medan since June up to sebtember 2005. This research aims to study the influence of Guano and Phosphate solvent microorganism to the availability of P-Nutrition and respons of maize on ultisol soil. This research applies Factorial...

  18. Isolation and Identification of Indigenous Plant Growth Promoting Rhizobacteria from Himalayan Region of Kashmir and their Effect on Improving Growth and Nutrient Contents of Maize (Zea Mays L.)

    OpenAIRE

    Mahwish eZahid

    2015-01-01

    IIntroduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant-microbes interactions that may affect ecosystems sustainability, agricultural productivity and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of one hundred isolates were isolated from these sites, out of ...

  19. Isolation and identification of indigenous plant growth promoting rhizobacteria from Himalayan region of Kashmir and their effect on improving growth and nutrient contents of maize (Zea mays L.)

    OpenAIRE

    Zahid, Mahwish; Abbasi, M. Kaleem; Hameed, Sohail; Rahim, Nasir

    2015-01-01

    Introduction and exploitation of plant growth promoting rhizobacteria (PGPR) in agro-ecosystems enhance plant–microbes interactions that may affect ecosystems sustainability, agricultural productivity, and environmental quality. The present study was conducted to isolate and identify PGPRs associated with maize (Zea mays L.) from twenty sites of Himalayan region of Hajira-Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. A total of 100 isolates were isolated from these sites, out of which ei...

  20. Tanggap Pertumbuhan dan Produksi Jagung (Zea mays L.) Varietas Pioneer-23 Terhadap Berbagai Komposisi Vermikompos dengan Pupuk Anorganik (N,P,K)

    OpenAIRE

    Nasution, Efrida Sari

    2013-01-01

    EFRIDA SARI NASUTION: The Response of Growth and Yield of Maize (Zea mays L.) Pioneer 23 Variety on Some Compotition of Vermicompost and Anorganic Fertilizer (N,P,K), supervised by MARIATI SINURAYA and ASIL BARUS. The research has been conducted to investigate the response of growth and yield of maize on some compotition of organic (vermicompost) and anorganic (N,P,K) fertilizer at Bunga Terompet street, Sempakata village chief, Medan Selayang subdistrict head, with a height...

  1. Bioactivity of a water extract of boldus (Peumus boldus Molina against Spodoptera frugiperda (J.E. Smith and Helicoverpa zea Boddie (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Gonzalo Silva

    2013-06-01

    Full Text Available The insecticidal properties of water-extract of Peumus boldus Molina and its effect on the development cycle and feeding habits of Spodoptera frugiperda J.E. Smith and Helicoverpa zea Boddie were evaluated under laboratory conditions in concentrations of 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0% (w/w. Spodoptera frugiperda was the most susceptible with 75% mortality at 7 d at 8% P. boldus concentration, while H. zea had only 30% mortality. LC50 was 2.31 mL kg-1 for S. frugiperda and 16.05 mL kg¹ for H. zea. When the extract concentration increased in the diet, larval size and weight, percentage of pupation and number of adults decreased, and the time required to reach those states was greater. Neonate larvae fed primarily on the diet with the lower extract concentration and the control was preferred by more than 50% of larvae. Inhibition of feeding, growth, weight gain of 3rd instar larvae as well as new biomass production decreased with concentration of the extract.

  2. Observaciones sobre didáctica

    Directory of Open Access Journals (Sweden)

    Alfonso Tamayo Valencia

    2014-02-01

    Full Text Available  En el presente artículo, a partir de la conceptualización sobre didáctica y enseñanza, se plantean sus posibilidades en la educación superior, especialmente cuando reflexionamos en las prácticas de enseñanza desde un saber hacer que supere el hacer de esquemas tácitos y espontáneos que caracteriza en buena parte docencia universitaria. Desde esta perspectiva se aboga por la renovación de la concepción de la didáctica desde una postura epistemológica y psicológica sobre la manera como se construye el conocimiento.

  3. Consideraciones sobre la motricidad del violinista

    OpenAIRE

    Allende, Pablo

    2009-01-01

    Comienza la exposición hablando de que intenta prevenir las patologías en los violinistas mediante secuencias de ejercicios específicos, de diferentes técnicas corporales y fisioterapéuticas. Presenta datos estadísticos sobre el índice de patologías que se encuentran entre estos intérpretes para por último presentar tablas de ejercicios propiamente dichas para intentar paliar estas dolencias

  4. Productos derivados sobre bienes de consumo

    OpenAIRE

    Francisco Venegas Martinez; Salvador Cruz Ake

    2010-01-01

    Este trabajo de investigacion desarrolla un modelo de equilibrio general con expectativas racionales en tiempo continuo util para la determinacion de precios de contratos forward, contratos futuros, bonos cupon cero y opciones europeas (de compra y venta) sobre bienes de consumo. Para ello, el modelo considera un individuo representativo en una economia con dos bienes, los cuales son producidos con tecnologias estocasticas. Por ultimo, el modelo propuesto permite examinar estrategias para obt...

  5. Reflexiones sobre el concepto de justicia

    Directory of Open Access Journals (Sweden)

    Víctor C. Pascual Planchuelo

    2005-06-01

    Full Text Available Este ensayo constituye una reflexión sobre el concepto de Justicia. No se centra, como tantos estudios al respecto, en el plano teórico y metafísico, sino que atiende problemas de mayor actualidad: la opinión de los ciudadanos, la postura de los profesionales y otros asuntos controvertidos del ámbito del Derecho.

  6. Neopolares de problemas de empaquetamiento sobre semigrupos

    OpenAIRE

    Aráoz Durand, Julián Arturo

    1982-01-01

    Los neopolares permiten caracterizar las caras de un poliedro combinatorio como vértices de poliedros altamente estructurados. Esto sirve para generar planos de cortes y para obtener propiedades duales en problemas de programación entera. Gomory caracterizó neopolares para problemas sobre grupos, Aráoz en "Polyhedral Neopolarities" extendió estos resultados a semigrupos de cubrimiento. En este trabajo se caracterizan neopolares importantes de semigrupos de empaquetamiento que incluyen los pro...

  7. Effect of Soil Aging on the Phytoremediation Potential of Zea mays in Chromium and Benzo[a]Pyrene Contaminated Soils.

    Science.gov (United States)

    Chigbo, Chibuike

    2015-06-01

    This study compared the phytoremediation potential of Zea mays in soil either aged or freshly amended with chromium (Cr) and benzo[a]pyrene (B[a]P). Z. mays showed increased shoot biomass in aged soils than in freshly spiked soils. The shoot biomass in contaminated soils increased by over 50% in aged soil when compared to freshly amended soils, and over 29% more Cr was accumulated in the shoot of Z. mays in aged soil than in freshly amended soil. Planting Z. mays in aged soil helped in the dissipation of more than 31% B[a]P than in freshly spiked soil, but in the absence of plants, there seemed to be no difference between the dissipation rates of B[a]P in freshly and aged co-contaminated soil. Z. mays seemed to enhance the simultaneous removal of Cr and B[a]P in aged soil than in freshly spiked soil and hence can be a good plant choice for phytoremediation of co-contaminated soils.

  8. Weed Control and Corn (Zea mays Response to Planting Pattern and Herbicide Program with High Seeding Rates in North Carolina

    Directory of Open Access Journals (Sweden)

    Mitchell K. Williams

    2014-01-01

    Full Text Available Effective weed control in corn (Zea mays L. is important to optimize yield. Concern over environmental impact of atrazine and selection for glyphosate resistance has increased the need to develop alternative strategies that use herbicides other than atrazine and glyphosate and appropriate cultural practices to control weeds. Research was conducted during 2011 and 2012 to determine weed and corn response to herbicide programs containing dicamba, glufosinate, and glyphosate applied postemergence alone or with atrazine in single- and twin-row planting patterns. Planting pattern had no effect on common ragweed (Ambrosia artemisiifolia L. and Texas panicum (Panicum texanum L. population and did not interact with herbicide program. Effective weed control hastened maturity in some but not all instances. Under weed-free conditions, corn grain yield was higher in 5 of 7 trials when planted in twin rows versus single rows at equivalent corn populations (141,000 plants ha−1. These results suggest that while planting pattern may not impact weed control dramatically, planting corn in twin rows may be an effective alternative to single-row planting patterns because of increased yield under high corn populations.

  9. Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

    Science.gov (United States)

    Nakamoto, T

    1995-03-01

    The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction.

  10. Potassium Management for Improving Growth and Grain Yield of Maize (Zea mays L.) under Moisture Stress Condition

    Science.gov (United States)

    Amanullah; Iqbal, Asif; Irfanullah; Hidayat, Zeeshan

    2016-01-01

    Potassium (K) fertilizer management is beneficial for improving growth, yield and yield components of field crops under moisture stress condition in semiarid climates. Field experiments were conducted to study the response of maize (Zea mays L., cv. Azam) to foliar and soil applied K during summer 2013 and 2014. The experiments were carried out at the Agronomy Research Farm of The University of Agriculture Peshawar, Northwest Pakistan under limited irrigation (moisture stress) condition. It was concluded from the results that application of foliar K at the rate of 1–3% and foliar Zn at the rate of 0.1–0.2% was more beneficial in terms of better growth, higher yield and yield components of maize under moisture stress condition. Early spray (vegetative stage) resulted in better growth and higher yield than late spray (reproductive stage). Soil K treated plots (rest) plots performed better than control (K not applied) in terms of improved growth, higher yield and yield components of maize crop. The results further demonstrated that increasing the rate of soil applied K up to 90 kg P ha−1 in two equal splits (50% each at sowing and knee height) improve growth and maize productivity under semiarid climates. PMID:27694964

  11. Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As)uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment. Non-mycorrhizal and zero-P addition controls were included. Plant biomass and concentrations and uptake of As, P, and other nutrients, AM colonization, root lengths, and hyphal length densities were determined. The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium. Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments, but shoot and root biomass of AM plants was depressed by P application. AM fungal inoculation decreased shoot As concentrations when no P was added, and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition, respectively. Shoot and root uptake of P, Mn, Cu, and Zn increased, but shoot Fe uptake decreased by 44.6%, with inoculation,when P was added. P addition reduced shoot P, Fe, Mn, Cu, and Zn uptake of AM plants, but increased root Fe and Mn uptake of the nonmycorrhizal ones. AM colonization therefore appeared to enhance plant tolerance to As in low P soil, and have some potential for the phytostabilization of As-contaminated soil, however, P application may introduce additional environmental risk by increasing soil As mobility.

  12. Effects of Liquid Organic Fertilizer on Time of Tasselling, Time of Silking and Grain Yield of Maize (Zea mays

    Directory of Open Access Journals (Sweden)

    Enujeke, E. C. and Ojeifo, I. M.

    2013-04-01

    Full Text Available A study was carried out in the Teaching and Research Farm of Delta State University, Asaba Campus from August to December in 2005 and repeated between March and July, 2006 to evaluate the response of maize (Zea mays to liquid organic fertilizer. The study was conducted using a split plot fitted into randomized complete block design. Liquid organic fertilizer was diluted at the rate of 60 ml of the product to 15 litres of water and applied to maize foliage, topsoil, foliage and topsoil at the rates of 5l/ha, 10l/ha, 151/ha, l8l/ha, 201/ha and 251/ha. The result obtained indicated a positive influence of liquid organic fertilizer on time of tasselling, time of silking and grain yield of maize. Liquid organic fertilizer significantly reduced the times of tasselling and silking, and increased grain yield of maize. Based on this study, it is recommended that 151/ha of liquid organic fertilizer which produced 5.6tha’ in 2005 and 6.1tha’ of dry grain yield 2006 be applied on the topsoil of maize plant with a view to maximally exploit the great economic potentials of the crop.

  13. Comparison of Three Methods for Determination of Root Hydraulic Conductivity of Maize (Zea mays L.) Root System

    Institute of Scientific and Technical Information of China (English)

    LI Qing-ming; LIU Bin-bin

    2010-01-01

    Three techniques of root pressure probe,pressure chamber and high pressure flow meter were used to measure the hydraulic conduetivities (Lp,) of whole root systems of young maize (Zea mays L.) seedlings grown hydroponically under either drought or normal water conditions.Compared to normal water conditions,drought stress simulated by polyethylene glycol 6 000 (osmotic potential=-0.2 MPa) reduced Lp,in the root system by over 50%.It indicated that water permeability in the roots decreased significantly when plants suffered from water shortages.Moreover,there was no significant difference (P<0.05) on the Lpr values in the root systems developed under a given water stress regime among the three techniques used.Therefore,all three methods are acceptable to study the hydraulic conductivity of maize seedling root systems.We have also highlighted some of the technical limitations of each method.It can be inferred that the root pressure probe is preferable for young maize seedlings because it is subtle and has the additional ability to determine solute transport properties,but the method is time consuming.Other advantages and disadvantages of each technique are discussed in order to acquaint researchers with basic information that could contribute to their choice of an appropriate technique for future studies.

  14. Enhancing the urea-N use efficiency in maize (Zea mays) cultivation on acid soils amended with zeolite and TSP.

    Science.gov (United States)

    Ahmed, Osumanu H; Hussin, Aminuddin; Ahmad, Husni M H; Rahim, Anuar A; Majid, Nik Muhamad Abd

    2008-01-01

    Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP) and zeolite (Clinoptilolite) on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays) cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives) did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf) production of Swan (test crop). All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea. PMID:18454247

  15. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Yu Tian

    2014-01-01

    Full Text Available A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.. Results indicated that the seeds primed by gibberellins (GA, NaCl, and polyethylene glycol (PEG reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P<0.05. The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM, or PEG (15% significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

  16. Isolation and Characterization of Fipronil Degrading Acinetobacter calcoaceticus and Acinetobacter oleivorans from Rhizospheric Zone of Zea mays.

    Science.gov (United States)

    Uniyal, Shivani; Paliwal, Rashmi; Verma, Megha; Sharma, R K; Rai, J P N

    2016-06-01

    An enrichment culture technique was used for the isolation of bacteria capable of utilizing fipronil as a sole source of carbon and energy. Based on morphological, biochemical characteristics and phylogenetic analysis of 16S rRNA sequence, the bacterial strains were identified as Acinetobacter calcoaceticus and Acinetobacter oleivorans. Biodegradation experiments were conducted in loamy sand soil samples fortified with fipronil (50 µg kg(-1)) and inoculated with Acinetobacter sp. cells (45 × 10(7) CFU mL(-1)) for 90 days. Soil samples were periodically analyzed by gas liquid chromatography equipped with electron capture detector. Biodegradation of fipronil fitted well with the pseudo first-order kinetics, with rate constant value between 0.041 and 0.051 days(-1). In pot experiments, fipronil and its metabolites fipronil sulfide, fipronil sulfone and fipronil amide were found below quantifiable limit in soil and root, shoot and leaves of Zea mays. These results demonstrated that A. calcoaceticus and A. oleivorans may serve as promising strains in the bioremediation of fipronil-contaminated soils. PMID:27084098

  17. Breeding for culinary and nutritional quality of common bean (Phaseolus vulgaris L. in intercropping systems with maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Rodino A.P.

    1999-01-01

    Full Text Available Common bean (Phaseolus vulgaris L. is widely intercropped with maize (Zea mays L. in the North of Spain. Breeding beans for multiple cropping systems is important for the development of a productive and sustainable agriculture, and is mainly oriented to minimize intercrop competition and to stabilize complementarity with maize. Most agricultural research on intercropping to date has focused on the agronomic and overall yield effects of the different species, but characters related with socio-economic and food quality aspects are also important. The effect of intercropping beans with maize on food seed quality traits was studied for thirty-five bush bean varieties under different environments in Galicia (Northwestern Spain. Parameters determining Asturian (Northern Spain white bean commercial and culinary quality have also been evaluated in fifteen accessions. There are significant differences between varieties in the selected cropping systems (sole crop, intercrop with field maize and intercrop with sweet maize for dry and soaked seed weight, coat proportion, crude protein, crude fat and moisture. Different white bean accessions have been chosen according to their culinary quality. Under these environmental conditions it appears that intercropping systems with sweet maize give higher returns than sole cropping system. It is also suggested that the culinary and nutritional quality potential of some white bean accessions could be the base material in a breeding programme the objectives of which are to develop varieties giving seeds with high food quality.

  18. Allelopathic effects of aqueous extracts of sunflower on wheat (triticum aestivum l.) and maize (zea mays l.)

    International Nuclear Information System (INIS)

    Sunflower is a potent allelopathic plant which possesses important allelochemicals with known allelopathic activity on other plants. In this study, allelopathic effects of fresh aqueous extracts (FAE) and air dried aqueous extracts (DAE) of root, shoot and leaves of sunflower (Halianthus annuus L.) were investigated on germination and seedling growth of wheat (Triticum aestivum L.) and maize (Zea mays L.) in seed bioassay experiments carried out at Botany Department of Peshawar University during 2010. Results showed significantly inhibitory effects of aqueous extracts on seed germination, growth and dry biomass of seedlings of wheat and maize. In wheat seedlings, significant germination inhibition (15.21%), increased mean germination time (MGT) (57.76%), reduced plumule and radical growth (21.66 and 28.44%) and lowered seedlings dry biomass (31.05%) were recorded under dry aqueous extracts of leaf when compared to control. Germination percentage of maize was inhibited by dry aqueous extracts of leaf by 7.81%, germination index by 16.51%, increased MGT by 25.53%, decreased plumule and radical lengths by 29.00 and 36.12% respectively, and lowered maize seedling dry biomass by 34.02 %. In both experiments, dry aqueous extracts (DAE) were more phytotoxic than fresh aqueous extracts (FAE). Similarly, inhibitory effects of aqueous extracts of different parts of sunflower were recorded in the order leaf > shoot > root for both tested plants. (author)

  19. Introgression of genetic material from Zea mays ssp. Mexicana into cultivated maize was facilitated by tissue culture

    International Nuclear Information System (INIS)

    Zea mays ssp. mexicana, a wild relative of cultivated maize (Z. mays ssp. mays), is a useful gene resource for maize breeding. In this study, two populations were generated by conventional breeding scheme (population I) or tissue culture regime (population II), respectively, to introgress genetic material of Z. mays ssp. mexicana into maize. Karyotype analysis showed that the arm ratios of 10 pairs of chromosomes in parent maize Ye515 and derivative lines from 2 different populations with 26% and 38% chromosome variation frequencies, respectively. Alien chromatin was detected in the root tip cells of progeny plants through genomic in situ hybridization (GISH). There were 3.3 chromosomes carrying alien chromatin on average in population I and 6.5 in population II. The hybridization signals were located mainly at the terminal or sub terminal regions of the chromosomes and the sizes were notably variant among lines. Based on those results, it is concluded that the introgression of genetic material from Z. mays ssp. mexicana into cultivated maize was facilitated by tissue culture, and subsequently some excellent materials for maize breeding were created. (author)

  20. The maize (Zea mays ssp. mays var. B73 genome encodes 33 members of the purple acid phosphatase gene family

    Directory of Open Access Journals (Sweden)

    Eliécer eGonzález Muñoz

    2015-05-01

    Full Text Available Purple acid phosphatases (PAPs play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73 reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members.

  1. Genetic characterization and linkage disequilibrium mapping of resistance to gray leaf spot in maize(Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    Liyu; Shi; Xiangling; Lv; Jianfeng; Weng; Hanyong; Zhu; Changlin; Liu; Zhuanfang; Hao; Yu; Zhou; Degui; Zhang; Mingshun; Li; Xiaoke; Ci; Xinhai; Li; Shihuang; Zhang

    2014-01-01

    Gray leaf spot(GLS),caused by Cercospora zeae-maydis,is an important foliar disease of maize(Zea mays L.)worldwide,resistance to which is controlled by multiple quantitative trait loci(QTL).To gain insights into the genetic architecture underlying the resistance to this disease,an association mapping population consisting of 161 inbred lines was evaluated for resistance to GLS in a plant pathology nursery at Shenyang in 2010 and 2011.Subsequently,a genome-wide association study,using 41,101 single-nucleotide polymorphisms(SNPs),identified 51 SNPs significantly(P<0.001)associated with GLS resistance,which could be converted into 31 QTL.In addition,three candidate genes related to plant defense were identified,including nucleotidebinding-site/leucine-rich repeat,receptor-like kinase genes similar to those involved in basal defense.Two genic SNPs,PZE-103142893 and PZE-109119001,associated with GLS resistance in chromosome bins 3.07 and 9.07,can be used for marker-assisted selection(MAS)of GLS resistance.These results provide an important resource for developing molecular markers closely linked with the target trait,enhancing breeding efficiency.

  2. Enhancing the Urea-N Use Efficiency in Maize (Zea mays Cultivation on Acid Soils Amended with Zeolite and TSP

    Directory of Open Access Journals (Sweden)

    Osumanu H. Ahmed

    2008-01-01

    Full Text Available Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP and zeolite (Clinoptilolite on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf production of Swan (test crop. All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea.

  3. Phosphorus and compost management influence maize (Zea mays productivity under semiarid condition with and without phosphate solubilizing bacteria

    Directory of Open Access Journals (Sweden)

    Amanullah eAmanullah

    2015-12-01

    Full Text Available Phosphorus (P unavailability and lack of organic matter in the soils under semiarid climates are the two major constraints for low crop productivity. Field trial was conducted to study the effects of P levels, compost application times and seed inoculation with phosphate solubilizing bacteria (PSB on the yield and yield components of maize (Zea mays L., cv. Azam. The experiment was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar-Pakistan during summer 2014. The experiment was laid out in randomized complete block design with split plot arrangement using three replications. The two PSB levels [(1 inoculated seed with PSB (+ and (2 seed not inoculated with PSB (- or control] and three compost application times [(30, 15 and 0 days before sowing (DBS] combination (six treatments were used as main plot factor, while four P levels (25, 50, 75 and 100 kg P ha-1 used as subplot factor. The results confirmed that compost applied at sowing time and P applied at the two higher rates (75 and 100 kg P ha-1 had significantly increased yield and yield components of maize under semiarid condition. Maize seed inoculated with PSB (+ had tremendously increased yield and yield components of maize over PSB-control plots (- under semiarid condition.

  4. Study of effects of Bt maize (Zea mays) events on Lepidoptera Ostrinia nubilalis, Sesamia nonagrioidesin southwestern France.

    Science.gov (United States)

    Folcher, L; Eychenne, N; Weissenberger, A; Jarry, M; Regnault-Roger, C; Delos, M

    2006-01-01

    Crops of maize (Zea mays L.) were conducted in southwestern France with GMO (Genetic Modified Organism) vs isogenetic varieties in order to verify the control of European Corn Borer (ECB) Ostrinia nubilalis (Hübner) and the Corn Stalk Borer (CBS) Sesamia nonagrioides (Lefevbre) by GMO in field conditions. The bioassays were carried out in 1998 and 1999 before moratorium, then in 2005. Experiments involved respectively 18, 12 and 19 fields cultivated with Furio/Furio cb (GMO), Cecilia/ Elgina (GMO) and PR33P66/PR33P67 (GMO) varieties. These transgenic events expressed Cry1A(b) protein (Bt maize). Plants were noted for insect infestation assessment (number of larvae in stalks and ears per plant). Statistical tests used t-test on couple of plots. Results showed a significant difference in the density of both ECB and CBS between control and the two transgenic events. The two transgenic events acted differently. The control of the two Bt events on the two pests were differentiated and discussed. These experiments underlined the importance of field evaluation for testing real effects of transgenic events on crop according the environmental context.

  5. Interactions between Fusarium verticillioides, Ustilago maydis, and Zea mays: an endophyte, a pathogen, and their shared plant host.

    Science.gov (United States)

    Rodriguez Estrada, Alma E; Jonkers, Wilfried; Kistler, H Corby; May, Georgiana

    2012-07-01

    Highly diverse communities of microbial symbionts occupy eukaryotic organisms, including plants. While many well-studied symbionts may be characterized as either parasites or as mutualists, the prevalent but cryptic endophytic fungi are less easily qualified because they do not cause observable symptoms of their presence within their host. Here, we investigate the interactions of an endophytic fungus, Fusarium verticillioides with a pathogen, Ustilago maydis, as they occur within maize (Zea mays). We used experimental inoculations to evaluate metabolic mechanisms by which these three organisms might interact. We assessed the impacts of fungal-fungal interactions on endophyte and pathogen growth within the plant, and on plant growth. We find that F. verticillioides modulates the growth of U. maydis and thus decreases the pathogen's aggressiveness toward the plant. With co-inoculation of the endophyte with the pathogen, plant growth is similar to that which would be gained without the pathogen present. However, the endophyte may also break down plant compounds that limit U. maydis growth, and obtains a growth benefit from the presence of the pathogen. Thus, an endophyte such as F. verticillioides may function as both a defensive mutualist and a parasite, and express nutritional modes that depend on ecological context.

  6. Alternative Splicing and Differential Expression of Two Transcripts of Nicotine Adenine Dinucleotide Phosphate Oxidase B Gene from Zea mays

    Institute of Scientific and Technical Information of China (English)

    Fan Lin; Yun Zhang; Ming-Yi Jiang

    2009-01-01

    With the exception of rice, little is known about the existence of respiratory burst oxidase homolog (rboh) gene in cereals. The present study reports the cloning and analysis of a novel rboh gene, termed ZmrbohB, from maize (Zea mays L.). The full-length cDNA of ZmrbohB encodes a 942 amino acid protein containing all of the respiratory burst oxidase homolog catalytically critical motifs.Altemative splicing of ZmrbohB has generated two transcript isoforms, ZmrbohB-α and -β. Spliced transcript ZmrbohB-β retains an unspliced intron 11 that carries a premature termination codon and probably leads to nonsense-mediated mRNA decay. Expression analysis showed that two splice isoforms were differentially expressed in various tissues and at different developmental stages, and the major product was ZmrbohB-α. The transcripts of ZmrbohB-α accumulated markedly when the maize seedlings were subjected to various abiotic stimuli, such as wounding, cold (4℃), heat (40℃), UV and salinity stress. In addition, several abiotic stimuli also affected the alternative splicing pattern of ZmrbohB except wounding. These results provide new insight into roles in the expression regulation of plant rboh genes and suggest that ZmrbohB gene may play a role in response to environmental stresses.

  7. Phytoextraction of cadmium by rice (Oryza sativa L.), soybean (Glycine max (L.) Merr.), and maize (Zea mays L.)

    International Nuclear Information System (INIS)

    Selecting a phytoextraction plant with high Cd-accumulating ability based on the plant's compatibility with mechanized cultivation techniques may yield more immediately practical results than selection based on high tolerance to Cd. Rice (Oryza sativa L., cv. Nipponbare and Milyang 23), soybean (Glycine max [L.] Merr., cv. Enrei and Suzuyutaka), and maize (Zea mays L., cv. Gold Dent) were grown on one Andosol and two Fluvisols with low concentration of Cd contamination ranging from 0.83 to 4.29 mg Cd kg-1, during 60 days in pots (550 mL) placed in a greenhouse. Shoot Cd uptake was as follows: Gold Dent < Enrei and Nipponbare < Suzuyutaka and Milyang 23. Several soil Cd fractions after Milyang 23 harvesting decreased most. Milyang 23 accumulated 10-15% of the total soil Cd in its shoot. The Milyang 23 rice is thus promising for phytoextraction of Cd from paddy soils with low contamination level. - Milyang 23 rice (Oryza sativa L.) accumulated 10-15% of the total soil Cd in its shoot

  8. Study of effects of Bt maize (Zea mays) events on Lepidoptera Ostrinia nubilalis, Sesamia nonagrioidesin southwestern France.

    Science.gov (United States)

    Folcher, L; Eychenne, N; Weissenberger, A; Jarry, M; Regnault-Roger, C; Delos, M

    2006-01-01

    Crops of maize (Zea mays L.) were conducted in southwestern France with GMO (Genetic Modified Organism) vs isogenetic varieties in order to verify the control of European Corn Borer (ECB) Ostrinia nubilalis (Hübner) and the Corn Stalk Borer (CBS) Sesamia nonagrioides (Lefevbre) by GMO in field conditions. The bioassays were carried out in 1998 and 1999 before moratorium, then in 2005. Experiments involved respectively 18, 12 and 19 fields cultivated with Furio/Furio cb (GMO), Cecilia/ Elgina (GMO) and PR33P66/PR33P67 (GMO) varieties. These transgenic events expressed Cry1A(b) protein (Bt maize). Plants were noted for insect infestation assessment (number of larvae in stalks and ears per plant). Statistical tests used t-test on couple of plots. Results showed a significant difference in the density of both ECB and CBS between control and the two transgenic events. The two transgenic events acted differently. The control of the two Bt events on the two pests were differentiated and discussed. These experiments underlined the importance of field evaluation for testing real effects of transgenic events on crop according the environmental context. PMID:17390797

  9. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    Science.gov (United States)

    Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method. PMID:25093210

  10. Iron fractions in the apoplast of intact root tips of Zea mays L. seedlings affected by nitrogen form

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effects of ammonium (NH+4- N ) and ni trate (NO-3- N ) Were examined on Fe fractions and FeCN (ferricyanide) reductase activity in intact root tips (0-3 em)of young maize (Zea mays L. cv. Lenz) in solution culture by using short-term experiment under controlled Fe deficiency conditions (containing high HCO-3 concentration in preculture solution). The results showed that Fe( II ) concentrations in root tip apoplast of maize were only 20-40 nmol/g FW which accounted for 7%-13% of total Fe. Most of Fe in root tips existed as Fe(Ⅲ) compounds. Imposition of the roots to NH+4 - N or NO-3 - N for 60 min led to an increase of Fe( II ) in root tip apoplast. NH+4 - N led to an increased concentration of Fe( II ) and exchangeable Fe (Fe( II ) and Fe (III)) in root tips, while NO-3 - N increased FeCN reductaseactivity. The relationship between pH and Fe fractions,FeCN reductase activity was also discussed.``

  11. [3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

    Science.gov (United States)

    Hall, P. J.; Bandurski, R. S.

    1986-01-01

    [3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37 degrees C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as alpha-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in only slight purification with large losses of activity. Chromatography over hydroxylapatite allowed separation of two enzymically active fractions, one of which catalyzed the hydrolysis of both indole-3-acetyl-myo-inositol and esterase substrates. With the other enzymic hydrolysis of esterase substrates was readily demonstrated, but no hydrolysis of indole-3-acetyl-myo-inositol was ever detected.

  12. Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity

    Science.gov (United States)

    Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

    1992-01-01

    Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

  13. Influence of microgravity on root-cap regeneration and the structure of columella cells in Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.; Fondren, W. M.; Wang, C. L.

    1987-01-01

    We launched imbibed seeds and seedlings of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on 1) root-cap regeneration, and 2) the distribution of amyloplasts and endoplasmic reticulum (ER) in the putative statocytes (i.e., columella cells) of roots. Decapped roots grown on Earth completely regenerated their caps within 4.8 days after decapping, while those grown in microgravity did not regenerate caps. In Earth-grown seedlings, the ER was localized primarily along the periphery of columella cells, and amyloplasts sedimented in response to gravity to the lower sides of the cells. Seeds germinated on Earth and subsequently launched into outer space had a distribution of ER in columella cells similar to that of Earth-grown controls, but amyloplasts were distributed throughout the cells. Seeds germinated in outer space were characterized by the presence of spherical and ellipsoidal masses of ER and randomly distributed amyloplasts in their columella cells. These results indicate that 1) gravity is necessary for regeneration of the root cap, 2) columella cells can maintain their characteristic distribution of ER in microgravity only if they are exposed previously to gravity, and 3) gravity is necessary to distribute the ER in columella cells of this cultivar of Z. mays.

  14. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Science.gov (United States)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  15. Growth and graviresponsiveness of primary roots of Zea mays seedlings deficient in abscisic acid and gibberellic acid

    Science.gov (United States)

    Moore, R.; Dickey, K.

    1985-01-01

    The objective of this research was to determine if gibberellic acid (GA) and/or abscisic acid (ABA) are necessary for graviresponsiveness by primary roots of Zea mays. To accomplish this objective we measured the growth and graviresponsiveness of primary roots of seedlings in which the synthesis of ABA and GA was inhibited collectively and individually by genetic and chemical means. Roots of seedlings treated with Fluridone (an inhibitor of ABA biosynthesis) and Ancymidol (an inhibitor of GA biosynthesis) were characterized by slower growth rates but not significantly different gravicultures as compared to untreated controls. Gravicurvatures of primary roots of d-5 mutants (having undetectable levels of GA) and vp-9 mutants (having undectable levels of ABA) were not significantly different from those of wild-type seedlings. Roots of seedlings in which the biosynthesis of ABA and GA was collectively inhibited were characterized by gravicurvatures not significantly different for those of controls. These results (1) indicate that drastic reductions in the amount of ABA and GA in Z. mays seedlings do not significantly alter root graviresponsiveness, (2) suggest that neither ABA nor GA is necessary for root gravicurvature, and (3) indicate that root gravicurvature is not necessarily proportional to root elongation.

  16. Study of Maize ((Zea mays L.) Varieties Comparison Test%玉米品种比较试验研究

    Institute of Scientific and Technical Information of China (English)

    岳明强; 阎旭东; 徐育鹏; 刘艳昆; 王秀领; 芮松青; 刘振敏; 陈善义

    2014-01-01

    [目的]确定玉米(Zea mays L.)品种在沦州地区的适应性、丰产性.[方法]对13个玉米品种进行品种比较试验.[结果]平玉8号、承玉23、大玉3号、中单909、张玉1355、蠡玉18产量表现较好,各产量性状优良,其中承玉23、张玉1355、蠡玉18生育期较长,适合沧州地区春播大面积示范推广,平玉8号、大玉3号、中单909生育期较短适合沧州地区夏播大面积示范推广.[结论]该研究可为沧州地区推广优良的玉米品种提供可靠依据.

  17. Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

    Energy Technology Data Exchange (ETDEWEB)

    Bi Xiangyang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Key Laboratory of Biogeology and Environmental Geology, Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: fengxinbin@vip.skleg.cn; Yang Yuangen [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Li Xiangdong; Shin, Grace P.Y. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Li Feili [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Qiu Guangle; Li Guanghui; Liu Taoze; Fu Zhiyou [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)

    2009-03-15

    Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake. - The sources and pathways of Pb and Cd accumulated in maize were assessed using Pb isotopes and Pb/Cd ratios.

  18. Cysteine- and glutathione-mediated uptake of lead and cadmium into Zea mays and Brassica napus roots

    Energy Technology Data Exchange (ETDEWEB)

    Vadas, Timothy M., E-mail: tvadas@umbc.ed [Department of Biological and Environmental Engineering, Cornell University, 320 Riley-Robb Hall, Ithaca, NY 14853 (United States); Ahner, Beth A., E-mail: baa7@cornell.ed [Department of Biological and Environmental Engineering, Cornell University, 320 Riley-Robb Hall, Ithaca, NY 14853 (United States)

    2009-08-15

    This study examines a new mechanism for the uptake of Pb and Cd into Brassica napus and Zea mays roots. During hydroponic experiments, the uptake of Pb and Cd was enhanced in the presence of cysteine and glutathione, whereas no or very low uptake was observed in EDTA and penicillamine controls. Uptake rates were also enhanced after pre-exposure to cysteine or glutathione and inhibited in the presence of vanadate, suggesting a biological mechanism of uptake. Increasing concentrations of glutathione in solution resulted in decreasing Pb uptake rates, indicating competition for transport between free-glutathione and Pb-glutathione species. Pb uptake in the presence of increasing cysteine concentrations resulted in decreased uptake initially but linearly increasing uptake at higher concentrations. Experimentation showed concentration dependent Pb uptake rates. We speculate that there are specific transporters for these thiol ligands and describe what barriers remain for application of this novel transport mechanism in chelator-assisted phytoremediation. - Cysteine and glutathione mediate the transport of lead and cadmium into plant roots.

  19. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila

    Energy Technology Data Exchange (ETDEWEB)

    Li, T.; Liu, M.J.; Zhang, X.T. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Zhang, H.B. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Department of Biology, Yunnan University, Kunming, 650091 Yunnan (China); Sha, T. [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China); Zhao, Z.W., E-mail: zhaozhw@ynu.edu.cn [Key Laboratory of Conservation and Utilization for Bioresources, Yunnan University, Kunming, 650091 Yunnan (China)

    2011-02-15

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. - Research Highlights: {yields}Effect of DSE (E. pisciphila) on heavy metal tolerance of maize host was studied. {yields}DSE alleviated the deleterious effect of excessive heavy metals on maize. {yields}DSE restricted the transfer of heavy metals from the roots to shoots in maize. {yields}DSE colonization improved the tolerance of their host plants to heavy metals.

  20. Molecular evolution and gene expression differences within the HD-Zip transcription factor family of Zea mays L.

    Science.gov (United States)

    Mao, Hude; Yu, Lijuan; Li, Zhanjie; Liu, Hui; Han, Ran

    2016-04-01

    Homeodomain-leucine zipper (HD-Zip) transcription factors regulate developmental processes and stress responses in plants, and they vary widely in gene number and family structure. In this study, 55 predicted maize HD-Zip genes were systematically analyzed with respect to their phylogenetic relationships, molecular evolution, and gene expression in order to understand the functional diversification within the family. Phylogenetic analysis of HD-Zip proteins from Zea mays, Oryza sativa, Arabidopsis thaliana, Vitis vinifera, and Physcomitrella patens showed that they group into four classes. We inferred that the copy numbers of classes I and III genes were relatively conserved in all five species. The 55 maize HD-Zip genes are distributed randomly on the ten chromosomes, with 15 segmental duplication and 4 tandem duplication events, suggesting that segmental duplications were the major contributors in the expansion of the maize HD-Zip gene family. Expression analysis of the 55 maize HD-Zip genes in different tissues and drought conditions revealed differences in the expression levels and patterns between the four classes. Promoter analysis revealed that a number of stress response-, hormone response-, light response-, and development-related cis-acting elements were present in their promoters. Our results provide novel insights into the molecular evolution and gene expression within the HD-Zip gene family in maize, and provide a solid foundation for future functional study of the HD-Zip genes in maize.

  1. Gravity induced, asymmetric unloading of indole-3-acetic acid from the stele of Zea mays into the mesocotyl cortex

    International Nuclear Information System (INIS)

    Previous studies from this laboratory have demonstrated an increase within 3 min in both free and ester indole-3-acetic acid (IAA) on the lower side of the mesocotyl cortex of a gravity stimulated Zea mays seedling. Since both free and ester IAA are being transported from endosperm to shoot through the stele these results suggest that the gravity stimulus affects movement of IAA and/or its esters from stele to cortex. To test this postulate they injected 5-(3H)-IAA into the endosperm and, after a 30 min period with the plants held vertically, severed the kernel from the shoot and placed the plants in a horizontal position. After 60 min the distribution of radioactivity in the mesocotyl cortex was 55 + 3% in the lower half and 45 + 3% in the upper half. These results support the working theory that a target for the gravity stimulus is the gating mechanism for the movement of hormone from stele to cortex

  2. [3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

    International Nuclear Information System (INIS)

    [3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 370C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as α-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in only slight purification with large losses of activity. Chromatography over hydroxylapatite allowed separation of two enzymically active fractions, one of which catalyzed the hydrolysis of both indole-3-acetyl-myo-inositol and esterase substrates. With the other fraction enzymic hydrolysis of esterase substrates was readily demonstrated, but no hydrolysis of indole-3-acetyl-myo-inositol was ever detected

  3. The effect of triazole induced photosynthetic pigments and biochemical constituents of Zea mays L. (Maize) under drought stress

    Science.gov (United States)

    Rajasekar, Mahalingam; Rabert, Gabriel Amalan; Manivannan, Paramasivam

    2016-06-01

    In this investigation, pot culture experiment was carried out to estimate the ameliorating effect of triazole compounds, namely Triadimefon (TDM), Tebuconazole (TBZ), and Propiconazole (PCZ) on drought stress, photosynthetic pigments, and biochemical constituents of Zea mays L. (Maize). From 30 days after sowing (DAS), the plants were subjected to 4 days interval drought (DID) stress and drought with TDM at 15 mg l-1, TBZ at 10 mg l-1, and PCZ at 15 mg l-1. Irrigation at 1-day interval was kept as control. Irrigation performed on alternative day. The plant samples were collected on 40, 50, and 60 DAS and separated into root, stem, and leaf for estimating the photosynthetic pigments and biochemical constituents. Drought and drought with triazole compounds treatment increased the biochemical glycine betaine content, whereas the protein and the pigments contents chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, and anthocyanin decreased when compared to control. The triazole treatment mitigated the adverse effects of drought stress by increasing the biochemical potentials and paved the way to overcome drought stress in corn plant.

  4. Changes in the distribution of plastids and endoplasmic reticulum during cellular differentiation in root caps of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1985-01-01

    In calyptrogen cells of Zea mays, proplastids are distributed randomly throughout the cell, and the endoplasmic reticulum (ER) is distributed parallel to the cell walls. The differentiation of calyptrogen cells into columella statocytes is characterized by the following sequential events: (1) formation of ER complexes at the distal and proximal ends of the cell, (2) differentiation of proplastids into amyloplasts, (3) sedimentation of amyloplasts onto the distal ER complex, (4) breakdown of the distal ER complex and sedimentation of amyloplasts to the bottom of the cell, and (5) formation of sheets of ER parallel to the longitudinal cell walls. Columella statocytes located in the centre of the cap each possess 4530 +/- 780 micrometers2 of ER surface area, an increase of 670 per cent over that of calyptrogen cells. The differentiation of peripheral cells correlates positively with (1) the ER becoming arranged in concentric sheets, (2) amyloplasts and ER becoming randomly distributed, and (3) a 280 per cent increase in ER surface area over that of columella statocytes. These results are discussed relative to graviperception and mucilage secretion, which are functions of columella and peripheral cells, respectively.

  5. Agrobacterium-mediated transformation of maize (Zea mays) with Cre-lox site specific recombination cassettes in BIBAC vectors.

    Science.gov (United States)

    Vega, Juan M; Yu, Weichang; Han, Fangpu; Kato, Akio; Peters, Eric M; Zhang, Zhanyuan J; Birchler, James A

    2008-04-01

    The Cre/loxP site-specific recombination system has been applied in various plant species including maize (Zea mays) for marker gene removal, gene targeting, and functional genomics. A BIBAC vector system was adapted for maize transformation with a large fragment of genetic material including a herbicide resistance marker gene, a 30 kb yeast genomic fragment as a marker for fluorescence in situ hybridization (FISH), and a 35S-lox-cre recombination cassette. Seventy-five transgenic lines were generated from Agrobacterium-mediated transformation of a maize Hi II line with multiple B chromosomes. Eighty-four inserts have been localized among all 10 A chromosome pairs by FISH using the yeast DNA probe together with a karyotyping cocktail. No inserts were found on the B chromosomes; thus a bias against the B chromosomes by the Agrobacterium-mediated transformation was revealed. The expression of a cre gene was confirmed in 68 of the 75 transgenic lines by a reporter construct for cre/lox mediated recombination. The placement of the cre/lox site-specific recombination system in many locations in the maize genome will be valuable materials for gene targeting and chromosome engineering.

  6. In vitro oxidation of indoleacetic acid by soluble auxin-oxidases and peroxidases from maize roots. [Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Beffa, R.; Martin, H.V.; Pilet, P.E. (Institute of Plant Biology and Physiology of the University, Lausanne (Switzerland))

    1990-10-01

    Soluble auxin-oxidases were extracted from Zea mays L. cv LG11 apical root segments and partially separated from peroxidases (EC 1.11.1.7) by size-exclusion chromatography. Auxin-oxidases were resolved into one main peak corresponding to a molecular mass of 32.5 kilodaltons and a minor peak at 54.5 kilodaltons. Peroxidases were separated into at least four peaks, with molecular masses from 32.5 to 78 kilodaltons. In vitro activity of indoleacetic acid-oxidases was dependent on the presence of MnCl{sub 2} and p-coumaric acid. Compound(s) present in the crude extract and several synthetic auxin transport inhibitors (including 2,3,5-triiodobenzoic acid and N-1-naphthylphthalamic acid) inhibited auxin-oxidase activity, but had no effect on peroxidases. The products resulting from the in vitro enzymatic oxidation of ({sup 3}H)indoleacetic acid were separated by HPLC and the major metabolite was found to cochromatograph with indol-3yl-methanol.

  7. Optimasi Konsentrasi Ekstrak Alang-Alang (Imperata cylindrica L. untuk Memacu Pertumbuhan dan Produksi Jagung Manis (Zea mays Saccharata Sturt

    Directory of Open Access Journals (Sweden)

    Mayta Novaliza Isda

    2016-03-01

    Full Text Available Sweet corn (Zea mays saccharata Struts a type of corn of high economic value, not only used for consumption also used to make syrup. Imperata is one of the weeds that interfere with crop cultivation, but efforts continue to be made use of weeds as an addition to soil organic matter. The study was conducted to determine the concentration of the extract Imperata (Imperata cylindrica L. appropriate in the sweet corn growth and determine the concentration of extract proper Imperata in the growth and production. The research method is a Completely Randomized Design (CRD with 9 treatments and 3 replicates. The results showed that treatment of Imperata extracts with varying concentrations significantly influenced the growth of plant height and leaf number. But not significantly to the growth of the leaf length, leaf width, stem diameter, number of rows per cob, number of seeds per row and plant dry weight. At a concentration of 200 g / 250 ml was able to reduce the vegetative and generative growth of sweet corn.

  8. SOWING AND PLANTING PERIOD ON YIELD AND EAR QUALITY OF SWEET CORN (Zea mays L. var. saccharata

    Directory of Open Access Journals (Sweden)

    Atnan Ugur

    2015-02-01

    Full Text Available Sweet corn (Zea mays L. var. saccharata attracts people with its amazing flavour. Adverse environmental factors decrease plant's cob yield and quality. A more effective production can be made by using resistant varieties and adjusting the sowing and plating periods. In this study, the effect of direct seed sowing and cultivating with seedlings in three different times (5, 15 and 25 May on the sweet corn's cob yield and certain quality features have been investigated. In the research hybrid sweet corn varieties; 2201, Challenger, Merit, Sunshine and Yellow Baby were used. Ear weight, ear yield, ear length, ear diameter, sequence in ear, kernel numbers in the sequence, dry weight, TSS, chroma and hue values have been identified in the study. The values obtained from cultivation with seedling have been found higher in all of the parameters except for TSS. With the progress of cultivation period while TSS and hue values in kernels have increased (9.72 to 20.94 chroma values have decreased. Husked ear weight values have changed between 184.69 to 224.11 g in varieties. The highest ear yield (3594.33 kg da-1 has been obtained from Merit by seedling planting cultivation on 15 May.

  9. Comentario sobre levantar la mano sobre uno mismo, de jean améry

    OpenAIRE

    Pilar González Rivera

    2010-01-01

    Resumen En el libro de Jean Améry (seudónimo de Hans Mayer), Levantar la mano sobre uno mismo. Discurso sobre la muerte voluntaria, el autor utiliza argumentos de orden filosófico y suministra algunos escasos datos autobiográficos (como la aterradora experiencia sufrida por él al haber sido víctima de la persecución y tortura nazis en dos ocasiones, debido a su condición de hijo de padre judío) para justificar la “muerte voluntaria”, como llama al sui...

  10. EVALUACIÓN MORFOAGRONÓMICA DE UNA POBLACIÓN DE MAÍZ (Zea mays, L. EN CONDICIONES DE POLINIZACIÓN ABIERTA EN EL MUNICIPIO BATABANÓ, PROVINCIA MAYABEQUE

    Directory of Open Access Journals (Sweden)

    Rosa Acosta Roca

    2013-01-01

    Full Text Available La variabilidad genética del maíz (Zea mays, L. es debida a los mismos mecanismos que operan en las poblaciones de los organismos en el proceso evolutivo, tanto en aquellas naturales como en las que están sometidas a domesticación; así como a los numerosos nichos ecológicos y los efectos ambientales que cada condición climática ejerce sobre las poblaciones en su adaptación. Sin embargo, han sido poco documentadas las experiencias de los programas de mejora genética desarrollado por productores en este cultivo. El presente trabajo muestra evidencias acerca de las ventajas de un programa de mejoramiento desarrollado en Cuba, para obtener poblaciones de maíz adaptadas a las condiciones de bajos insumos en Batabanó, provincia Mayabeque. La evaluación morfoagronómica de la población en estudio evidenció que la misma se caracteriza por presentar plantas altas, con tallos de mediano grosor, hojas de ancho medio y una tendencia a tener de 1 a 2 mazorcas. Estas tienen buena cobertura, son largas y delgadas de forma cónica-cilíndrica, con pocas hileras dispuestas ligeramente en espiral y granos numerosos semidentados de color naranja. Se comprobó que los caracteres cuantitativos del grano y la mazorca fueron en los que se ejerció mayor presión de selección, influyendo en la determinación de las características morfológicas de la población final, coincidiendo con los patrones genéticos del tipo Canilla. Los mayores resultados de la población «RAUL» con respecto al testigo en el rendimiento, validan la selección efectuada por el productor, siendo un indicador de las ventajas de los procesos de fitomejoramiento participativo en plantas alógamas.

  11. 玉米苞叶中新黄酮类化合物的分离和鉴定%Isolation and Identification of Novel Flavonoids from the Bract of Zea mays L

    Institute of Scientific and Technical Information of China (English)

    张沐新; 刘银燕; 孙薇; 杨晓虹; 王广树

    2011-01-01

    从玉米(Zea maysL)苞叶乙醇提取物中分离得到了4个黄酮类化合物,采用UV,IR,MS,1D NMR和2D NMR方法对化合物的结构进行了鉴定,它们分别为苜蓿素(1)、苜蓿素-5-O-β-D-吡喃葡萄糖苷(2)、苜蓿素-7-O-β-D-吡喃葡萄糖苷(3)和苜蓿素-7-O-[β-D-呋喃芹糖基-(1-2)]β-D-吡喃葡萄糖苷(4).其中,化合物4为新化合物,化合物1~3为首次从该植物中分离得到.%Zea mays ( maize) , a member of the Poaceae, is the most economically important crop in China,about 24 million hectares of Zea mays has been cultivated each year in China, there is about 600 kg of the bract of Zea mays per hectare, and thus the resources of the bract of Zea mays is extremely rich. Although there are some pharmacological activity researches about radical scavenging activity against hydroxyl radical and superoxide anion radical, reducing blood lipid and inhibiting arteriosclerosis, the studies on phytochemical constituents of the bract of Zea mays have not been reported. In order to utilize the resources of the bract ofZea mays, we investigated the chemical constituents of the bract of Zea mays. The air-dried bract ol Zea mays was extracted with 95% ethanol at room temperature, the extract was subjected to Diaion AB-8 column chro-matography eluated with ethanol-H2O, and the eluate was further chromatographed on silica gel and Sephadex LH-20 columns repeatedly to yield 4 flavonoid compounds. Their structures were identified as tricin( 1) , tricin 5-0-β-D-glucopyranoside(2) , tricin 7-O-/M>-glucopyranoside(3) , tricin 7-0-[β-D-apifuranosyl( 1-+2) ]-β-D-glucopyranoside(4) by spectral analysis(UV, IR, MS and ID, 2D NMR) , respectively. Among them, compound 4 is a new flavonoid compound, compounds 1, 2 and 3 are firstly isolated from this plant.

  12. 玉蜀黍叶中氨基酸及无机元素的含量测定%Determination of Amino Acids and Inorganic Elements in the leaves of Zea mays L.

    Institute of Scientific and Technical Information of China (English)

    刘银燕; 杨晓虹; 陈滴; 王文娜; 孙琦; 杨锦竹

    2012-01-01

    对玉蜀黍叶中氨基酸和无机元素进行研究.采用日立835-50型氨基酸分析仪和ICP - AES法对玉蜀黍叶中氨基酸和无机元素进行了研究.结果表明,玉蜀黍叶中含有17种氨基酸和12种人体必需的无机元素.本研究为玉蜀黍叶的药用开发提供了参考依据.%To determine amino acids and inorganic elements in the leaves of zea mays L., amino acids in leaves of zea mays L. Were determined by the amino acid analyzer, and inorganic elements in leaves of zea mays L. Were determined by ICP-AES. The result showed thai there were 17 amino acids and 12 kind of inorganic elements in leaves of zea mays L., and it provide a basis for the medical exploitation oi the leaves of zea mays L..

  13. ESTUDO SOBRE O IMPACTO DOS PROCESSADORES HOSPEDEIROS

    Directory of Open Access Journals (Sweden)

    Alba S. B. Lopes

    2008-05-01

    Full Text Available Arquiteturas reconfiguráveis são dispositivos de hardware capazes de modificar sua estrutura de hardware de acordo com a aplicação a ser executada. Tais dispositivos surgiram como uma alternativa às soluções de hardware tradicionais na tentativa de equilibrar flexibilidade e desempenho. Uma das principais formas de utilização de arquiteturas reconfiguráveis corresponde a um bloco reconfigurável anexado a um processador hospedeiro. Esse processador é responsável por executar diversas tarefas críticas, incluindo o particionamento hardware/software e indicar o momento do bloco reconfigurável executar. Apesar de existirem diversas propostas de arquiteturas reconfiguráveis na literatura, pouco se estudou sobre o impacto do processador hospedeiro na arquitetura. Nesse contexto, esse artigo apresenta um estudo sobre o impacto do processador hospedeiro no desempenho da arquitetura reconfigurável híbrida. Como estudo de caso foi realizada uma avaliação sobre o uso dos processadores SPARC V8 da Sun Microsystems e Nios II da Altera como processadores hospedeiros da arquitetura reconfigurável híbrida RoSA. O objetivo deste estudo é realizar a comparação entre o desempenho desses processadores e identificar qual deles é o mais adequado para anexar a arquitetura em questão. Os resultados mostraram que foi possível alcançar até 47% de ganho de desempenho com o uso do processador Nios II em comparação ao SPARC V8, indicando o primeiro como mais adequado para a arquitetura RoSA. PALAVRAS-CHAVE: arquiteturas reconfiguráveis, processador hospedeiro, desempenho.

  14. Literatura infantil sobre problemas infantiles: la diabetes

    OpenAIRE

    Lázaro Fernández, Patricia

    2015-01-01

    Debido al creciente número de casos de diabetes infantil que se está dando en la sociedad actual, no es raro encontrarse en las aulas cada vez más casos de esta enfermedad. Por esta razón, he decidido analizar dos libros sobre esta temática, para hacer un acercamiento del material seleccionado a las aulas y poder desarrollar junto con los niños un aprendizaje colectivo y cooperativo. En este trabajo se expone la importancia de la literatura y la literatura infantil como una ...

  15. Claves sobre el poder de las mujeres

    OpenAIRE

    García de León Álvarez, María Antonia

    2012-01-01

    El objeto de este texto es esbozar una síntesis sobre algunos nudos de mi obra en el área de Género y Poder. El estudio del poder es un punto de partida ineludible para abordar todo tema de Género, es decir, es necesario arrancar desde la comprensión del fenómeno social del poder, ya que el Patriarcado es un sistema estructurado de poder por género. Este punto de partida indica la relevancia del tema (nada más ni nada menos que el poder, tema clave en las Ciencias Sociales).

  16. Mapping sobre arquitecturas heterogéneas

    OpenAIRE

    De Giusti, Laura Cristina

    2008-01-01

    La programación de algoritmos paralelos, a diferencia de los algoritmos secuenciales, no cuenta para su representación con un único modelo. Esa carencia ocasiona que su aplicación sobre una arquitectura heterogénea, a través de modelos existentes, no halle el resultado que se ambiciona. La computación paralela ha propuesto, como pocas, significativos quiebres en el ámbito de la Ciencia de la Computación, al provocar la reformulación y generación de nuevos conceptos. El desarrollo de nuevos mo...

  17. Apuntes Sobre el Cultivo del Cacao.

    Directory of Open Access Journals (Sweden)

    Ochoa Horacio Ochoa

    1940-12-01

    Full Text Available En el presente artículo se hablara del proceso de fermentación del cacao, pero antes de entrar a detallar este proceso, es conveniente dar algunas anotaciones sobre los sistemas de recolección o “cosecha” empleados en distintos lugares, pues ellos tienen sus diferencias y en ocasiones no se efectúan con todo el cuidado necesario tanto para el árbol como para el producto que irá a los depósitos de fermentación.

  18. Futuros: estudo de caso sobre futuros cambiais

    OpenAIRE

    Santo, Paula Cristina Rosa da Silva Espírito

    2010-01-01

    Mestrado em Contabilidade A presente dissertação foi realizada com vista à obtenção do grau de mestre em Contabilidade pelo Instituto Superior de Contabilidade e Administração de Lisboa. Para o desenvolvimento desta dissertação foi escolhido o tema “Contratos de Futuros”. Em termos estruturais esta monografia divide-se em duas partes. Na primeira parte faz-se uma exposição sobre o tema os “Futuros”. Na segunda parte é apresentado o trabalho de investigação que foi desenvolvido. Na...

  19. Algunas reflexiones sobre la supervivencia empresarial

    OpenAIRE

    Sarabia Alzaga, José María

    1995-01-01

    Dos bloques-tópico, bien conocidos, configuran el esquema lógico de las reflexiones que se proponen. El primero de ellos se centra en nuestra realidad global: el entorno; el segundo, en los impactos que éste ha generado en la empresa, exponiendo una síntesis contrastada -y hoy día vigente- sobre cómo las empresas de éxito están consiguiendo sobrevivir. Como conclusión, se sintetizan algunas ideas o lineas generales de actuación que pudieran ayudar a mejorar o reforzar las propias experiencias...

  20. Sentencias Constitucionales sobre la muerte digna

    OpenAIRE

    Serrano, J. M.

    2006-01-01

    La sentencia comentada ha sido considerada como relevante en la discusión sobre el derecho a la vida en relación con la eutanasia. Sin embargo, las peculiaridades del caso qeu le dio origen y la propia argumentación del tribunal la alejan d euna interpretación relevante en torno a los dos tópicos del derecho a la vida y a la dignidad. Por el contrario la sentencia resulta decepcionate en su argumentación más propia. Primero respecto a la propia huelga de hambre que condena sin matices en rela...

  1. Consideraciones sobre de la ética

    OpenAIRE

    Enrique Cantolla Bernal

    2005-01-01

    El presente ensayo muestra como el hombre, a través de la historia, a estado constantemente buscando beneficios para su vida y ha debido cumplir con varias tareas, que con el tiempo han dado origen a costumbres y comportamientos que han llevado a constituir la moral y la ética. Esta última, nos permite definir y determinar los principales fines de la vida del hombre y cuales son los principios y normas que lo rigen. Así, el estudio de la ética nos plantea la interrogante sobre "los fines de l...

  2. Puntualizaciones sobre el concepto de latencia

    OpenAIRE

    Bortolazzo, Antonela

    2007-01-01

    El presente escrito revisa un concepto elaborado por Freud, como es la noción de Período de latencia sexual. Antes de hacer explícito el enfoque desde el cual será abordado quisiera mencionar que, lo que a continuación se desarrolla se enmarca en el trabajo de investigación que sobre el concepto de Latencia realiza, desde hace catorce años, la Cátedra de Psicología Evolutiva I, de la cual formo parte. En esta oportunidad me propongo indagar el concepto de latencia en el marco de la teoría ...

  3. Notas sobre envidia, equilibrio y optimalidad

    OpenAIRE

    Cristini, Marcela; Chisari, Omar Osvaldo

    1980-01-01

    Demostramos aquí -aún para coeficientes de producción distintos de la unidad- la suficiencia de las características del equilibrio para determinar el efecto aludido sobre la situación de ambos agentes. Damos otra condición suficiente, que no supone necesariamente el equilibrio; generalizamos los resultados a un número mayor de consumidores y deducimos propiedades del óptimo de Pareto, definido como aquella situación en la que no es posible mejorar el nivel de utilidad de un agente sin reducir...

  4. Efecto de masticar chicle sobre la halitosis

    OpenAIRE

    De Luca Monasterios, Fiorella; Chimenos Küstner, Eduardo; López López, José

    2014-01-01

    Fundamento y objetivo: Este estudio pretende estimar la prevalencia de halitosis oral en una población joven y mostrar el efecto del chicle sobre el aliento. Pacientes y método: Estudio prospectivo de campo descriptivo correlacional, de corte transversal. Se seleccionaron a conveniencia 121 jóvenes, de los que 98 concluyeron el estudio, el cual se realizó en el Hospital Odontológico Universitario-Universidad de Barcelona. El protocolo consistió en: cuestionario, evaluación clínica oral, prueb...

  5. El tullido. Un cuento sobre los cuentos

    OpenAIRE

    Fernández-Urtasun, R. (Rosa)

    2005-01-01

    Este artículo realiza una lectura literaria y simbólica de El tullido, uno de los cuentos de Christian Andersen que pasó desapercibido entre los relatos que se publicaron tras su muerte. El relato del argumento va acompañado de una reflexión sobre los temas que aparecen recogidos en el texto: las tradiciones orales, la belleza del arte, la esperanza, la creación, la importancia de la escritura y de la lectura, la esencia de la literatura.

  6. Ensayo sobre la melancolía

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    Marta Chacón Salinas

    2013-07-01

    Full Text Available Este trabajo es un intento de delimitar la melancolía del conjunto de los trastornos depresivos y de reflexionar sobre sus características tal como aparecen en el discurso de los melancólicos. Se consideran algunas hipótesis en la línea psicoanalítica freudiana y lacaniana (Lambottc, Kristeva para entender cómo se va constituyendo en sus características principales: la intolerancia a la pérdida del objeto y el desfallecimiento del símbolo que le impide elaborar este duelo.

  7. Recursos sobre propiedad intelectual en internet

    OpenAIRE

    Sorli Rojo, Ángela; Merlo Vega, José Antonio

    2001-01-01

    El concepto de propiedad intelectual, entendido en su sentido más amplio, englobaría todos los aspectos relacionados con los derechos que se obtienen de una creación, tanto en su forma original, como de sus posibles reproducciones y transformaciones. En este trabajo se recopilan y analizan una serie de fuentes de información accesibles en Internet sobre este tema. No obstante, la idea de propiedad intelectual no coincide plenamente con la de propiedad industrial, que es mucho m...

  8. Productos derivados sobre bienes de consumo

    OpenAIRE

    Francisco Venegas Martínez; Salvador Cruz Ake

    2010-01-01

    Este trabajo de investigación desarrolla un modelo de equilibrio general con expectativas racionales en tiempo continuo útil para la determinación de precios de contratos forward , contratos futuros, bonos cupón cero y opciones europeas (de compra y venta) sobre bienes de consumo. Para ello, el modelo considera un individuo representativo en una economía con dos bienes, los cuales son producidos con tecnologías estocásticas. Por último, el modelo propuesto permite examinar estrategias para o...

  9. Avances sobre bases de datos no convencionales

    OpenAIRE

    Arroyuelo, Jorge; Esquivel, Susana Cecilia; Grosso, Alejandro; Ludueña, Verónica; Reyes, Nora Susana; Chávez, Edgar; Navarro, Gonzalo

    2014-01-01

    En la actualidad han surgido, debido a los avances alcanzados en tecnologías de información y comunicación, aplicaciones no tradicionales sobre bases de datos de todo tipo de datos, valga la redundancia. Éstos pueden ser imágenes, texto libre, secuencias de ADN, audio, video, etc., pueden estar o no estructurados y provenir de diversas fuentes (satélites, telescopios, revistas, fotografías, música, etc.), como también ser de diferentes tamaños, generalmente muy grandes. Por otro lado, las con...

  10. Soportes apoyados sobre vigas pretensadas (EE. UU.

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1965-12-01

    Full Text Available This work has been awarded a prize by the Prestreesed Concrete Institute. It refers to a number of flyovers on the Arroyo Seco, of California. This river has been canalized, to help drainage in case of heavy rainfall. The canal runs through a highly populated zone, and a motor road and accessory ramps had to cross the canal. The resulting design involves three prestressed girders, lightly arched in a parabolic outline, resting on each river shore, running along the line of the bridge, over the canal. It was decided that the bridge piles should not rest on the river bed, in order not to reduce its flow capacity. The girders of a maximum length of 39 ms, are box shaped, and stiffened with thin diaphragms. The cylindrical pile, 1.50 m in diameter, is an integral part of the girder, and applies to it a concentrated load of about 4000 tons. The girders rest on reinforced concrete cubes, which in turn are supported by concrete slabs and piles driven into the soil.Esta obra ha sido premiada por el Prestressed Concrete Institute y se refiere a una serie de pasos superiores sobre el Arroyo Seco, en California, que se ha canalizado para servir de desagüe en el caso de avenidas torrenciales. El canal se halla en una zona de edificación densa y se trata del paso—sobre aquél—de una autopista y rampas de acceso. La solución adoptada consistió en tres vigas pretensadas, ligeramente arqueadas con perfil parabólico, apoyadas en las dos márgenes y situadas en correspondencia con los tres soportes, sobre el propio canal, ya que ninguno de aquéllos debía apoyarse en el lecho de este último al objeto de no disminuir su capacidad de desagüe. Las vigas—de unos 39 m de longitud la mayor—son del tipo cajón, rigidizadas con unos diafragmas de pequeño espesor. El soporte cilíndrico, de 1,50 m de diámetro, se solidariza con la viga y le transmite una notable carga concentrada, del orden de 4.000 toneladas. Los apoyos de estas vigas son simples dados

  11. Reflexiones sobre contabilidad privada y contabilidad nacional

    OpenAIRE

    José Arturo Gutiérrez

    1995-01-01

    Se discuten las interrelaciones de la contabilidad privada y la contabilidad nacional, insistiendo en sus condicionantes internos contradictorios en relación con la sobredeterminación de la formación económico-social vigente. En relación con ello se introduce la reflexión sobre la unidad contradictoria entre empresa y capital, esto es, la base técnica frente a su determinante socioeconómico, conflicto que la propia contabilidad privada expresa: al describir el capital aporta necesariamente el...

  12. Técnica de amostragem para comparar o dano causado pela lagarta-da-espiga, Heliothis zea (Boddie, em cultivares de milho Sampling techniques to compare the damage by Heliothis zea (Boddie in corn varieties

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    Violeta Nagai

    1986-01-01

    Full Text Available Neste trabalho, realizado no Instituto Agronômico, determinou-se o tamanho da amostra para estudos de danos causados pela lagarta-da-espiga, Heliothis zea (Boddie, avaliados pelo método de Widstrom. Foram utilizados dados de dois experimentos de campo, com um cultivar resistente (Asteca Prolífico VRPE VII, um suscetível (híbrido duplo IAC Hmd 7974, o 'Maya XVI' e o híbrido simples HS 7777, em 1978/79 e 1979/80. O critério para estimar o tamanho da amostra foi de que esse tamanho permitisse detectar uma diferença de 10 ou de 20% da média geral entre médias de danos, em cultivares de milho, e avaliar o dano médio por cultivar com erro-padrão de 10 ou de 20% da média. Para definir o processo de amostragem, utilizou-se o método de componentes de variância, estimados a partir de dois modelos matemáticos. O tamanho da amostra foi bastante variável entre cultivares, sendo maior no resistente. Entre os possíveis tamanhos mínimos de amostra para detectar uma diferença de 10% da média geral entre médias de danos de tratamentos, podem ser utilizados seis blocos com quatro linhas de 24 plantas; para uma diferença de 20% de média, cinco blocos com três linhas de seis plantas são suficientes. Para estimar a média de danos por cultivar, com erro-padrão de 10% de média, são necessários sete blocos com quatro linhas de 30 plantas, no cultivar Asteca, e cinco blocos com duas linhas de 24 plantas nos cultivares Hmd 7974, HS 7777 e Maya e, com erro-padrão de 20% de média, cinco blocos de três linhas com doze plantas, no 'Asteca', e cinco blocos com duas linhas de seis plantas nos demais cultivares.A study was made to determine the sample size for research on corn resistance to corn ear worm Heliothis zea (Boddie. The damage was measured using the Widstrom centimeter scale. The criteria used to select the sample sizes were such that a difference between two treatments of ten percent or twenty percent of the overall mean should be

  13. Tributos sobre a folha ou sobre o faturamento? Efeitos quantitativos para o Brasil

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    Tiago V Cavalcanti

    2008-09-01

    Full Text Available Este artigo estuda os impactos alocativos e de bem-estar de uma reforma tributária que substitui os impostos sobre a folha de salários por outro que incide sobre a receita. Para isso, desenvolve-se um modelo neoclássico de crescimento econômico com impostos sobre a receita e sobre a folha de salários. As simulações com parâmetros da economia brasileira mostram que tal reforma tributária tem um efeito negativo no bem-estar, no estoque de capital de longo prazo e consequentemente no produto per capita de longo prazo. Contudo, o emprego aumenta.This paper studies the impacts of a tax reform which substitutes taxes on labor income by taxes on total revenue. In order to accomplish that, we construct and solve a general equilibrium neoclassical growth model with taxes on labor income and total revenue. The numerical simulations with Brazilian parameters show that such tax reforms would negatively affect welfare, the capital stock, and consequently per capita output. However, employment would increase. Such effects are quantitatively important.

  14. Consideraciones criminológicas sobre las bandas juveniles

    OpenAIRE

    Medina, Juanjo, Ralphs, Robert, Aldridge, Judith

    2010-01-01

    Este artículo ofrece una serie de reflexiones originales sobre la definición de las bandas juveniles y resume algunos de los debates claves en el campo de investigación sobre bandas. En particular, se presta especial atención a los estudios sobre la relación entre bandas y delincuencia, las teorías que explican la formación de las bandas y los factores que empujan a los jóvenes a vincularse a las mismas, los estudios sobre respuestas de política criminal a este fenómeno, ...

  15. Milk line as an indicator of the harvesting time of three hybrid seeds of corn (Zea mays L.

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    Célio Trzeciak dos Santos

    2005-03-01

    Full Text Available The experiment was carried out to evaluate the time for harvesting seeds of three hybrids of corn (Zea mays L. at their best physiological quality and the use of the milk line as an indicator of the physiological seed maturity. Single hybrids CD 1723 and CD 5501 and double hybrid OC 705 seeds were collected for 59 days, every four days, starting 23 days after female flowering. Seed dry weight, moisture content, germination, vigour (cold and accelerated aging tests, black layer formation and seed milk line development were analysed. The harvesting time started 47 days after female flowering with high physiological quality of the seeds identified by a joint analysis of those seven characteristics of them. The milk line at stage 4 proved to be the best indicator of the time to harvest corn seeds for maximum physiological quality, because different stages of milk line development in corn seeds could be easily identified in the filed without any special equipment.O experimento foi conduzido durante o ano agrícola de 1996/97 em área experimental da Cooperativa de Desenvolvimento Econômico e Tecnológico (Coodetec, em Cascavel, Paraná, com o objetivo de avaliar o efeito da época de colheita de três híbridos de milho (Zea mays L. na qualidade fisiológica das sementes e o uso da linha de solidificação do endosperma como indicativo da maturidade fisiológica das sementes. O plantio foi realizado em 30 de setembro de 1996. Amostras de sementes dos híbridos simples CD 1723 e CD 5501, bem como do híbrido duplo OC 705, foram colhidas em intervalos de quatro dias, durante 59 dias, iniciando-se a colheita no vigésimo terceiro dia após o florescimento feminino. As características avaliadas nas sementes foram o acúmulo de matéria seca, o conteúdo de umidade, a germinação, o vigor (pelos testes de frio e de envelhecimento acelerado, a formação da camada preta e o desenvolvimento da linha de solidificação do endosperma. A colheita dos tr

  16. Sobre los límites

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    Walter Cabrera-Febola

    2014-10-01

    Full Text Available El intercambio de información entre entes naturales se produce a través de los boundaries [límites], este hecho reclama un estudio sistemático de ellos, lo cual hasta el momento no se ha realizado. En el presente trabajo, establecemos el concepto general de boundary, para luego identificar ciertos tipos de boundaries como interface, límite, borde y algunos de sus tipos, y barrera son identificados y conceptualizados. Luego realizamos un estudio parcial de algunos de los boundaries conceptualizados, tratando de analizarlos lo más posible. Finalmente, se da una discusión general sobre la existencia e importancia de los boundaries remarcando la generalidad y robustez del concepto de boundary y sus diferentes tipos, de aquí su utilidad en la ciencia y la tecnología es posible de apreciarse. Por último se comenta sobre su perspectiva en ciencia y tecnología.

  17. Efeitos de citocininas sobre a anatomia foliar e o crescimento de Annona glabra L. durante o cultivo in vitro e ex vitro Effects of cytokinins on the leaf anatomy and growth of Annona glabra L. during in vitro and ex vitro culture

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    Lenaldo Muniz de Oliveira

    2008-08-01

    Full Text Available O efeito de diferentes fontes de citocininas durante o cultivo in vitro de A. glabra sobre características anatômicas de folhas e crescimento das plantas foi avaliado neste trabalho. BAP (6-benzilaminopurina e KIN (cinetina induziram aumento na espessura do mesofilo, enquanto que ZEA (zeatina promoveu aumento na densidade e no índice estomático e no desenvolvimento do sistema vascular de folhas. A utilização de KIN e BAP proporcionou maior desenvolvimento e taxa de sobrevivência das plantas durante as fases de enraizamento e aclimatização.The effect of different sources of cytokinins during the in vitro cultivation of A. glabra on anatomical characteristics of leaves and plant growth was evaluated in this work. BAP (6-benzilaminopurine and KIN (kinetin induced an increase in leaf mesophyll thickness, while the ZEA (zeatin promoted an increase in density and stomatic index and development of leaves vascular system. The utilization of KIN and BAP improved higher plant development and survival rate during the acclimatization and rooting phases.

  18. Abscisic acid refines the synthesis of chloroplast proteins in maize (Zea mays in response to drought and light.

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    Xiuli Hu

    Full Text Available To better understand abscisic acid (ABA regulation of the synthesis of chloroplast proteins in maize (Zea mays L. in response to drought and light, we compared leaf proteome differences between maize ABA-deficient mutant vp5 and corresponding wild-type Vp5 green and etiolated seedlings exposed to drought stress. Proteins extracted from the leaves of Vp5 and vp5 seedlings were used for two-dimensional electrophoresis (2-DE and subsequent matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF mass spectrometry (MS. After Coomassie brilliant blue staining, approximately 450 protein spots were reproducibly detected on 2-DE gels. A total of 36 differentially expressed protein spots in response to drought and light were identified using MALDI-TOF MS and their subcellular localization was determined based on the annotation of reviewed accession in UniProt Knowledgebase and the software prediction. As a result, corresponding 13 proteins of the 24 differentially expressed protein spots were definitely localized in chloroplasts and their expression was in an ABA-dependent way, including 6 up-regulated by both drought and light, 5 up-regulated by drought but down-regulated by light, 5 up-regulated by light but down-regulated by drought; 5 proteins down-regulated by drought were mainly those involved in photosynthesis and ATP synthesis. Thus, the results in the present study supported the vital role of ABA in regulating the synthesis of drought- and/or light-induced proteins in maize chloroplasts and would facilitate the functional characterization of ABA-induced chloroplast proteins in C(4 plants.

  19. Zea mays Taxilin protein negatively regulates opaque-2 transcriptional activity by causing a change in its sub-cellular distribution.

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    Nan Zhang

    Full Text Available Zea mays (maize Opaque-2 (ZmO2 protein is an important bZIP transcription factor that regulates the expression of major storage proteins (22-kD zeins and other important genes during maize seed development. ZmO2 is subject to functional regulation through protein-protein interactions. To unveil the potential regulatory network associated with ZmO2, a protein-protein interaction study was carried out using the truncated version of ZmO2 (O2-2 as bait in a yeast two-hybrid screen with a maize seed cDNA library. A protein with homology to Taxilin was found to have stable interaction with ZmO2 in yeast and was designated as ZmTaxilin. Sequence analysis indicated that ZmTaxilin has a long coiled-coil domain containing three conserved zipper motifs. Each of the three zipper motifs is individually able to interact with ZmO2 in yeast. A GST pull-down assay demonstrated the interaction between GST-fused ZmTaxilin and ZmO2 extracted from developing maize seeds. Using onion epidermal cells as in vivo assay system, we found that ZmTaxilin could change the sub-cellular distribution of ZmO2. We also demonstrated that this change significantly repressed the transcriptional activity of ZmO2 on the 22-kD zein promoter. Our study suggests that a Taxilin-mediated change in sub-cellular distribution of ZmO2 may have important functional consequences for ZmO2 activity.

  20. Deciphering the role of NADPH oxidase in complex interactions between maize (Zea mays L.) genotypes and cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert

    2016-07-22

    Plant NADPH oxidases (NOXs) encompass a group of membrane-bound enzymes participating in formation of reactive oxygen species (ROS) under physiological conditions as well as in response to environmental stressors. The purpose of the survey was to unveil the role of NADPH oxidase in pro-oxidative responses of maize (Zea mays L.) seedling leaves exposed to cereal aphids' infestation. The impact of apteral females of bird cherry-oat aphid (Rhopalosiphum padi L.) and grain aphid (Sitobion avenae F.) feeding on expression levels of all four NADPH oxidase genes (rbohA, rbohB, rbohC, rbohD) and total activity of NOX enzyme in maize plants were investigated. In addition, inhibitory effect of diphenylene iodonium (DPI) pre-treatment on NOX activity and hydrogen peroxide content in aphid-stressed maize seedlings was studied. Leaf infestation biotests were accomplished on 14-day-old seedlings representing two aphid-resistant varieties (Ambrozja and Waza) and two aphid-susceptible ones (Tasty Sweet and Złota Karłowa). Insects' attack led to profound upregulation of rbohA and rbohD genes in tested host plants, lower elevations were noted in level of rbohB mRNA, whereas abundance of rbohC transcript was not significantly altered. It was uncovered aphid-induced enhancement of NOX activity in examined plants. Higher increases in expression of all investigated rboh genes and activity of NADPH oxidase occurred in tissues of more resistant maize cultivars than in susceptible ones. Furthermore, DPI treatment resulted in strong reduction of NOX activity and H2O2 accumulation in aphid-infested Z. mays plants, thus evidencing circumstantial role of the enzyme in insect-elicited ROS generation. PMID:27178208

  1. Deliberate ROS production and auxin synergistically trigger the asymmetrical division generating the subsidiary cells in Zea mays stomatal complexes.

    Science.gov (United States)

    Livanos, Pantelis; Galatis, Basil; Apostolakos, Panagiotis

    2016-07-01

    Subsidiary cell generation in Poaceae is an outstanding example of local intercellular stimulation. An inductive stimulus emanates from the guard cell mother cells (GMCs) towards their laterally adjacent subsidiary cell mother cells (SMCs) and triggers the asymmetrical division of the latter. Indole-3-acetic acid (IAA) immunolocalization in Zea mays protoderm confirmed that the GMCs function as local sources of auxin and revealed that auxin is polarly accumulated between GMCs and SMCs in a timely-dependent manner. Besides, staining techniques showed that reactive oxygen species (ROS) exhibit a closely similar, also time-dependent, pattern of appearance suggesting ROS implication in subsidiary cell formation. This phenomenon was further investigated by using the specific NADPH-oxidase inhibitor diphenylene iodonium, the ROS scavenger N-acetyl-cysteine, menadione which leads to ROS overproduction, and H2O2. Treatments with diphenylene iodonium, N-acetyl-cysteine, and menadione specifically blocked SMC polarization and asymmetrical division. In contrast, H2O2 promoted the establishment of SMC polarity and subsequently subsidiary cell formation in "younger" protodermal areas. Surprisingly, H2O2 favored the asymmetrical division of the intervening cells of the stomatal rows leading to the creation of extra apical subsidiary cells. Moreover, H2O2 altered IAA localization, whereas synthetic auxin analogue 1-napthaleneacetic acid enhanced ROS accumulation. Combined treatments with ROS modulators along with 1-napthaleneacetic acid or 2,3,5-triiodobenzoic acid, an auxin efflux inhibitor, confirmed the crosstalk between ROS and auxin functioning during subsidiary cell generation. Collectively, our results demonstrate that ROS are critical partners of auxin during development of Z. mays stomatal complexes. The interplay between auxin and ROS seems to be spatially and temporarily regulated. PMID:26250135

  2. Uptake and effects of a mixture of widely used therapeutic drugs in Eruca sativa L. and Zea mays L. plants.

    Science.gov (United States)

    Marsoni, Milena; De Mattia, Fabrizio; Labra, Massimo; Bruno, Antonia; Bruno, Antonella; Bracale, Marcella; Vannini, Candida

    2014-10-01

    Pharmaceutically active compounds (PACs) are continuously dispersed into the environment due to human and veterinary use, giving rise to their potential accumulation in edible plants. In this study, Eruca sativa L. and Zea mays L. were selected to determine the potential uptake and accumulation of eight different PACs (Salbutamol, Atenolol, Lincomycin, Cyclophosphamide, Carbamazepine, Bezafibrate, Ofloxacin and Ranitidine) designed for human use. To mimic environmental conditions, the plants were grown in pots and irrigated with water spiked with a mixture of PACs at concentrations found in Italian wastewaters and rivers. Moreover, 10× and 100× concentrations of these pharmaceuticals were also tested. The presence of the pharmaceuticals was tested in the edible parts of the plants, namely leaves for E. sativa and grains for Z. mays. Quantification was performed by liquid chromatography mass spectroscopy (LC/MS/MS). In the grains of 100× treated Z. mays, only atenolol, lincomycin and carbamazepine were above the limit of detection (LOD). At the same concentration in E. sativa plants the uptake of all PACs was >LOD. Lincomycin and oflaxacin were above the limit of quantitation in all conditions tested in E. sativa. The results suggest that uptake of some pharmaceuticals from the soil may indeed be a potential transport route to plants and that these environmental pollutants can reach different edible parts of the selected crops. Measurements of the concentrations of these pharmaceuticals in plant materials were used to model potential adult human exposure to these compounds. The results indicate that under the current experimental conditions, crops exposed to the selected pharmaceutical mixture would not have any negative effects on human health. Moreover, no significant differences in the growth of E. sativa or Z. mays plants irrigated with PAC-spiked vs. non-spiked water were observed. PMID:25042244

  3. Compost and crude humic substances produced from selected wastes and their effects on Zea mays L. nutrient uptake and growth.

    Science.gov (United States)

    Palanivell, Perumal; Susilawati, Kasim; Ahmed, Osumanu Haruna; Majid, Nik Muhamad

    2013-01-01

    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation. PMID:24319353

  4. Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

    Directory of Open Access Journals (Sweden)

    Perumal Palanivell

    2013-01-01

    Full Text Available Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA, crude fulvic acids (CFA, crude humin (CH, soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants’ diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation.

  5. Growth and yield of maize (Zea mays L. in response to herbicide application in the coastal savannah ecozone of Ghana

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    E. Larbi

    2013-09-01

    Full Text Available Field studies were conducted at the University of Ghana, Legon farm from June to September 2005 to investigate the growth and yield of maize (Zea mays in response to herbicide application. Four groups of herbicides; 2,4-D (Bextra and Calliherbe, glyphosate (Kalach 360SL, Fire and Weed Out, Atrazine (Callitraz 500SC and Trazine 500SC and Paraquat (Gramoxone Super and Benaxone were used. Each of the named herbicides constituted a treatment, with hand weeding as the control. In all, there were ten treatments and four replicates arranged in a randomized complete block design. Paraquat and gyphosate treatments were applied before sowing; Atrazine and 2,4-D were applied two days after sowing. The compound fertilizer 15-15-15 (N-P-K at the rate of 250 kg/ha was applied as side dressing 2 WAP. Top dressing with sulphate of ammonia at rate of 125 kg/ha was applied 6 WAP. Analysis of variance (ANOVA for the data was carried out using (Genstat 5 statistical package, 1997. Significant differences between means were estimated by the Least Significant Difference at 5% level of significance. Results revealed that dry matter accumulation, leaf area were similar in all treatments across the sample period. Glyphosate, Paraquat and Atrazine treatment had dry matter accumulation similar to the control. 2,4-D treatment however had higher dry matter at 2 WAP. Although there was no difference in the number of kernels per plant among the various treatments 2,4-D treatment plots produced 33 to 41% less as compared to the control in yield per hectare.

  6. Effects of citrate-coated silver nanoparticles on interactions between soil bacteria and the major crop plant Zea mays

    Science.gov (United States)

    Doody, Michael; Bais, Harsh; Jin, Yan

    2014-05-01

    The increasing use of silver nanoparticles (AgNPs) in commercial antimicrobial products presents an opportunity for increased environmental exposures. While the behavior of AgNPs in surface waters is becoming increasingly understood, little research has been conducted on the effects of these, or any nanoparticles, on soil-dwelling bacteria and major crop plants. Because of the importance of soil bacteria to the overall health of natural and agricultural soils, it is necessary to better understand how AgNPs interact with common bacterial species such as Bacillus subtilis and Escherichia coli. It is further necessary to quantify the effect of AgNPs on major crop plants, including Zea mays, a staple crop for much of the world. Finally, research is needed on how complex plant-microbe interactions that originate in the rhizosphere may be disrupted by AgNPs. Our preliminary data show highly statistically significant growth inhibition near 30% for both species of bacteria exposed to 1.0 mg L-1 citrate-coated AgNPs (c-AgNPs). Growth curves compiled from absorbance data show a similar dose-response for both species. Treatment with aqueous Ag as AgNO3 slightly inhibits E. coli (90 ± 5 %), but enhances growth of B. subtilis to 127 ± 23% of control. These results indicate that toxicity may be related to specific nano-scale properties of the c-AgNPs. On-going experiments measure potential growth inhibition, root development and morphology of Z. mays exposed to c-AgNPs, and resulting changes in plant-microbe interactions.

  7. Risk assessment for Helicoverpa zea (Lepidoptera: Noctuidae) resistance on dual-gene versus single-gene corn.

    Science.gov (United States)

    Edwards, Kristine T; Caprio, Michael A; Allen, K Clint; Musser, Fred R

    2013-02-01

    Recent Environmental Protection Agency (EPA) decisions regarding resistance management in Bt-cropping systems have prompted concern in some experts that dual-gene Bt-corn (CrylA.105 and Cry2Ab2 toxins) may result in more rapid selection for resistance in Helicoverpa zea (Boddie) than single-gene Bacillus thuringiensis (Bt)-corn (CrylAb toxin). The concern is that Bt-toxin longevity could be significantly reduced with recent adoption of a natural refuge for dual-gene Bt-cotton (CrylAc and Cry2Ab2 toxins) and concurrent reduction in dual-gene corn refuge from 50 to 20%. A population genetics framework that simulates complex landscapes was applied to risk assessment. Expert opinions on effectiveness of several transgenic corn and cotton varieties were captured and used to assign probabilities to different scenarios in the assessment. At least 350 replicate simulations with randomly drawn parameters were completed for each of four risk assessments. Resistance evolved within 30 yr in 22.5% of simulations with single-gene corn and cotton with no volunteer corn. When volunteer corn was added to this assessment, risk of resistance evolving within 30 yr declined to 13.8%. When dual-gene Bt-cotton planted with a natural refuge and single-gene corn planted with a 50% structured refuge was simulated, simultaneous resistance to both toxins never occurred within 30 yr, but in 38.5% of simulations, resistance evolved to toxin present in single-gene Bt-corn (CrylAb). When both corn and cotton were simulated as dual-gene products, cotton with a natural refuge and corn with a 20% refuge, 3% of simulations evolved resistance to both toxins simultaneously within 30 yr, while 10.4% of simulations evolved resistance to CrylAb/c toxin.

  8. Uptake and effects of a mixture of widely used therapeutic drugs in Eruca sativa L. and Zea mays L. plants.

    Science.gov (United States)

    Marsoni, Milena; De Mattia, Fabrizio; Labra, Massimo; Bruno, Antonia; Bruno, Antonella; Bracale, Marcella; Vannini, Candida

    2014-10-01

    Pharmaceutically active compounds (PACs) are continuously dispersed into the environment due to human and veterinary use, giving rise to their potential accumulation in edible plants. In this study, Eruca sativa L. and Zea mays L. were selected to determine the potential uptake and accumulation of eight different PACs (Salbutamol, Atenolol, Lincomycin, Cyclophosphamide, Carbamazepine, Bezafibrate, Ofloxacin and Ranitidine) designed for human use. To mimic environmental conditions, the plants were grown in pots and irrigated with water spiked with a mixture of PACs at concentrations found in Italian wastewaters and rivers. Moreover, 10× and 100× concentrations of these pharmaceuticals were also tested. The presence of the pharmaceuticals was tested in the edible parts of the plants, namely leaves for E. sativa and grains for Z. mays. Quantification was performed by liquid chromatography mass spectroscopy (LC/MS/MS). In the grains of 100× treated Z. mays, only atenolol, lincomycin and carbamazepine were above the limit of detection (LOD). At the same concentration in E. sativa plants the uptake of all PACs was >LOD. Lincomycin and oflaxacin were above the limit of quantitation in all conditions tested in E. sativa. The results suggest that uptake of some pharmaceuticals from the soil may indeed be a potential transport route to plants and that these environmental pollutants can reach different edible parts of the selected crops. Measurements of the concentrations of these pharmaceuticals in plant materials were used to model potential adult human exposure to these compounds. The results indicate that under the current experimental conditions, crops exposed to the selected pharmaceutical mixture would not have any negative effects on human health. Moreover, no significant differences in the growth of E. sativa or Z. mays plants irrigated with PAC-spiked vs. non-spiked water were observed.

  9. Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

    Science.gov (United States)

    Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

    2014-05-01

    Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses.

  10. Influence of corn (Zea mays L seed processing with a locally produced sheller on seed quality and their damage

    Directory of Open Access Journals (Sweden)

    Pratima Pandey

    2013-06-01

    Full Text Available Maize (Zea mays dis.L. is one of the most important staple crops in the world. Sindhupalchok, Kavre and Nuwakot were the three districts selected for the maize CBSP groups under the respective Agriculture Development Offices identified by CDD for the present study. Altogether 2x6x3 samples for the study were collected. Seed damage as broken seeds, damages on embryo, seed quality assessments like seed moisture content, pure seed percentage, seed vigor measured by root and shoot length, seed germination, and embryo damages were carried in seed testing laboratory in Seed Science & Technology Division (SSTD Khumaltar following the ISTA Rules, 2007. For the embryo damage test, tetrazolium salt test (TZ was conducted following the procedures prescribed for maize seed in ISTA Rules, 2007. All the samples possessed of 99 % of pure seed. It ranged from 99.51 % in Nuwakot to 99.96 % in Kavre for samples using corn sheller. They were found within the standards for pure seed and were of acceptable range. The corn sheller was found as efficient as that of hand shelling. There was not found the effect on the quality of seed that they were within the standard values. The germination percentage decreased from initial 96 to 85 (Kavre; 94 to 87 (Sindhupalchwok and 91 to 83 (Nuwakot. This study concludes that the corn sheller techniques offer Wooden corn sheller is a simple but traditional device made locally for shelling the maize kernels and distributed to Community based seed production (CBSP farmers contribute to minimizing the impacts of hand sheller on agricultural systems.

  11. Yields and Yield Components of Maize (Zea Mays L. and Soybean (Glycine Max as Affected by Different Tillage Methods

    Directory of Open Access Journals (Sweden)

    Kvaternjak Ivka

    2015-12-01

    Full Text Available At the experiment station of the Krizevci College of Agriculture, yield and yield components of maize (Zea mays L. and soybean (Glycine max grown in rotation under five different methods of tillage were investigated. The aim of this study was to determine the effect of different tillage methods on yield and yield components of maize and soybean. The results and the determined number of plants per hectare of maize and soybean show that more favorable conditions for germination are in variants where ploughing performed in the autumn (variants C, D and E. During a four-year study, the minimum number of plants per hectare of maize and soybean was found in variant A. The dry season in panicle stage of maize in 2006 has lowered yields compared to 2008, and the drought in 2007 during the seed-filling period reduced the yield and the 1000 kernel weight of soybean compared with 2009 in all variants of tillage methods. The highest grain yield of maize was recorded in variant B. During 2006, with the unfavorable weather conditions, the lowest grain yield of maize was recorded in variant E with intensive tillage treatment. The highest yield of soybean was recorded in variant E, but there were no statistically significant differences compared to variants with the reduction of additional tillage interventions (variant B, C and D. With respect to maize grain and soybean seed yield, variant A was the lowest. Considering the achieved yields of maize grain, there is a possibility of reducing additional tillage interventions, whilst for achieving higher yield of soybean seed intensive tillage is recommended.

  12. A novel beta-glucosidase from the cell wall of maize (Zea mays L.): rapid purification and partial characterization

    Science.gov (United States)

    Nematollahi, W. P.; Roux, S. J.

    1999-01-01

    Plants have a variety of glycosidic conjugates of hormones, defense compounds, and other molecules that are hydrolyzed by beta-glucosidases (beta-D-glucoside glucohydrolases, E.C. 3.2.1.21). Workers have reported several beta-glucosidases from maize (Zea mays L.; Poaceae), but have localized them mostly by indirect means. We have purified and partly characterized a 58-Ku beta-glucosidase from maize, which we conclude from a partial sequence analysis, from kinetic data, and from its localization is not identical to any of those already reported. A monoclonal antibody, mWP 19, binds this enzyme, and localizes it in the cell walls of maize coleoptiles. An earlier report showed that mWP19 inhibits peroxidase activity in crude cell wall extracts and can immunoprecipitate peroxidase activity from these extracts, yet purified preparations of the 58 Ku protein had little or no peroxidase activity. The level of sequence similarity between beta-glucosidases and peroxidases makes it unlikely that these enzymes share epitopes in common. Contrary to a previous conclusion, these results suggest that the enzyme recognized by mWP19 is not a peroxidase, but there is a wall peroxidase closely associated with the 58 Ku beta-glucosidase in crude preparations. Other workers also have co-purified distinct proteins with beta-glucosidases. We found no significant charge in the level of immunodetectable beta-glucosidase in mesocotyls or coleoptiles that precedes the red light-induced changes in the growth rate of these tissues.

  13. Effects of ethylene on the kinetics of curvature and auxin redistribution in gravistimulated roots of Zea mays

    Science.gov (United States)

    Lee, J. S.; Evans, M. L.

    1990-01-01

    We tested the involvement of ethylene in maize (Zea mays L.) root gravitropism by measuring the kinetics of curvature and lateral auxin movement in roots treated with ethylene, inhibitors of ethylene synthesis, or inhibitors of ethylene action. In the presence of ethylene the latent period of gravitropic curvature appeared to be increased somewhat. However, ethylene-treated roots continued to curve after control roots had reached their final angle of curvature. Consequently, maximum curvature in the presence of ethylene was much greater in ethylene-treated roots than in controls. Inhibitors of ethylene biosynthesis or action had effects on the kinetics of curvature opposite to that of ethylene, i.e. the latent period appeared to be shortened somewhat while total curvature was reduced relative to that of controls. Label from applied 3H-indole-3-acetic acid was preferentially transported toward the lower side of stimulated roots. In parallel with effects on curvature, ethylene treatment delayed the development of gravity-induced asymmetric auxin movement across the root but extended its duration once initiated. The auxin transport inhibitor, 1-N-naphthylphthalamic acid reduced both gravitropic curvature and the effect of ethylene on curvature. Since neither ethylene nor inhibitors of ethylene biosynthesis or action prevented curvature, we conclude that ethylene does not mediate the primary differential growth response causing curvature. Because ethylene affects curvature and auxin transport in parallel, we suggest that ethylene modifies curvature by affecting gravity-induced lateral transport of auxin, perhaps by interfering with adaptation of the auxin transport system to the gravistimulus.

  14. Helicoverpa zea (Lepidoptera: Noctuidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Responses to Sorghum bicolor (Poales: Poaceae) Tissues From Lowered Lignin Lines.

    Science.gov (United States)

    Dowd, Patrick F; Sattler, Scott E

    2015-01-01

    The presence of lignin within biomass impedes the production of liquid fuels. Plants with altered lignin content and composition are more amenable to lignocellulosic conversion to ethanol and other biofuels but may be more susceptible to insect damage where lignin is an important resistance factor. However, reduced lignin lines of switchgrasses still retained insect resistance in prior studies. Therefore, we hypothesized that sorghum lines with lowered lignin content will also retain insect resistance. Sorghum excised leaves and stalk pith Sorghum bicolor (L.) Moench (Poales: Poaceae) from near isogenic brown midrib (bmr) 6 and 12 mutants lines, which have lowered lignin content and increased lignocellulosic ethanol conversion efficiency, were examined for insect resistance relative to wild-type (normal BTx623). Greenhouse and growth chamber grown plant tissues were fed to first-instar larvae of corn earworms, Helicoverpa zea (Boddie) and fall armyworms Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), two sorghum major pests. Younger bmr leaves had significantly greater feeding damage in some assays than wild-type leaves, but older bmr6 leaves generally had significantly less damage than wild-type leaves. Caterpillars feeding on the bmr6 leaves often weighed significantly less than those feeding on wild-type leaves, especially in the S. frugiperda assays. Larvae fed the pith from bmr stalks had significantly higher mortality compared with those larvae fed on wild-type pith, which suggested that bmr pith was more toxic. Thus, reducing lignin content or changing subunit composition of bioenergy grasses does not necessarily increase their susceptibility to insects and may result in increased resistance, which would contribute to sustainable production. PMID:25601946

  15. Impacts of industrial waste resources on maize (Zea mays L.) growth, yield, nutrients uptake and soil properties.

    Science.gov (United States)

    Singh, Satnam; Young, Li-Sen; Shen, Fo-Ting; Young, Chiu-Chung

    2014-10-01

    Discharging untreated highly acidic (pH4.0), organic and nutrients rich monosodium glutamate wastewater (MW), and highly alkaline (pH>10.0) paper-mill wastewater (PW) causes environmental pollution. When acidity of MW neutralized (pH 6.5±0.1) with PW and lime (treatments represented as MW+PW and MW+Lime), then MW may be utilized as a potential source of nutrients and organic carbon for sustainable food production. Objectives of this study were to compare the effects of PW and lime neutralized MW and chemical fertilizers on maize (Zea mays L. cv. Snow Jean) plant growth, yield, nutrients uptake, soil organic matter and humic substances. The field experiment was carried out on maize using MW at 6000 L ha(-1). Impacts of the MW application on maize crop and soil properties were evaluated at different stages. At harvest, plant height, and plant N and K uptake were higher in MW treatment. Leaf area index at 60 days after sowing, plant dry matter accumulation at harvest, and kernels ear(-1) and 100-kernel weight were higher in MW+Lime treatment. Kernel N, P, K, Mn, Fe and Zn, and plant Zn uptake were highest in MW+Lime. Plant Fe uptake, and soil organic matter and humic substances were highest in MW+PW. The MW+PW and MW+Lime treatments exhibited comparable results with chemically fertilized treatment. The MW acidity neutralized with lime showed positive impacts on growth, yield and nutrients uptake; nevertheless, when MW pH neutralized with PW has an additional benefit on increase in soil organic matter and humic substances.

  16. Location of transported auxin in etiolated maize shoots using 5-azidoindole-3-acetic acid. [Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A.M. (Univ. of North Carolina, Chapel Hill (USA))

    1990-07-01

    A study was undertaken using the photoaffinity labeling agent, tritiated 5-azidoindole-3-acetic acid (({sup 3}H),5-N{sub 3}IAA), to identify cells in the etiolated maize (Zea mays L.) shoot which transport auxin. Transport of ({sup 3}H),5-N{sub 3}IAA was shown to be polar, inhibited by 2,3,5-triiodobenzoic acid (TIBA) and essentially freely mobile. There was no detectable radiodecomposition of ({sup 3}H),5-N{sub 3}IAA within tissue kept in darkness for 4 hours. Shoot tissue which had taken up ({sup 3}H),5-N{sub 3}IAA was irradiated with ultraviolet light to covalently fix the photoaffinity labeling agent within cells that contained it at the time of photolysis. Subsequent microautoradiography showed that all cells contained radioactivity; however, the amount of radioactivity varied among different cell types. Epidermal cells contained the most radioactivity per area, approximately twofold more than other cells. Parenchyma cells in the mature stelar region contained the next largest amount and cortical cells, sieve tube cells, tracheary cells, and all cells in the leaf base contained the least amount of the radioactive label. Two observations suggest that the auxin within the epidermal cells is transported in a polar manner: (a) the amount of auxin in the epidermal cells is greatly reduced in the presence of TIBA, and (b) auxin accumulates on the apical side of a wound in the epidermis and is absent on the basal side. While these results indicate that auxin in the epidermis is polarly transported, this tissue cannot be the only pathway since the epidermis is only a small fraction of the shoot volume.

  17. Combining Tpi and CO1 Genetic Markers to Discriminate Invasive Helicoverpa armigera From Local Helicoverpa zea (Lepidoptera: Noctuidae) Populations in the Southeastern United States.

    Science.gov (United States)

    Nagoshi, Rodney N; Gilligan, Todd M; Brambila, Julieta

    2016-10-01

    The recent establishment of the Old World pest Helicoverpa armigera (Hübner) into South America has had significant economic consequences and places the rest of the hemisphere at risk, emphasizing the need for improved methods of monitoring. A major complication is that a sibling species endemic to the New World, Helicoverpa zea (Boddie), is morphologically very similar, with the two species capable of producing fertile hybrids in the laboratory. The consequences of such hybridization in the field are uncertain, but could result in significant and unpredictable changes in the timing, range, and pesticide susceptibilities of Helicoverpa infestations. The objective here is to provide new genetic resources applicable to Helicoverpa populations in northern Florida and neighboring states (a region at risk for H. armigera) that can distinguish the two species and possible hybrids. The genetic variability in segments of the mitochondrial cytochrome oxidase 1 (CO1) and the Z-linked triosephosphate isomerase (Tpi) genes were determined for H. zea from the southeastern United States. These were compared to DNA sequences from H. armigera specimens from Morocco, Australia, and Europe. Phylogenetic network analysis showed a clear demarcation between the two species for all gene segments. These results extend earlier studies establishing CO1 as marker for discriminating the Helicoverpa species complex and introduce a new sex-linked genomic marker. The CO1 and Tpi markers in combination provide a more accurate and sensitive method than existing techniques for identifying hybridization between H. zea and H. armigera and could potentially be used to extrapolate the likely source of invasive H. armigera populations.

  18. A Multiplex Real-Time PCR Assay to Diagnose and Separate Helicoverpa armigera and H. zea (Lepidoptera: Noctuidae in the New World.

    Directory of Open Access Journals (Sweden)

    Todd M Gilligan

    Full Text Available The Old World bollworm, Helicoverpa armigera (Hübner, and the corn earworm, H. zea (Boddie, are two of the most important agricultural pests in the world. Diagnosing these two species is difficult-adults can only be separated with a complex dissection, and larvae cannot be identified to species using morphology, necessitating the use of geographic origin for identification in most instances. With the discovery of H. armigera in the New World, identification of immature Helicoverpa based on origin is no longer possible because H. zea also occurs in all of the geographic regions where H. armigera has been discovered. DNA barcoding and restriction fragment length polymorphism (RFLP analyses have been reported in publications to distinguish these species, but these methods both require post-PCR processing (i.e., DNA sequencing or restriction digestion to complete. We report the first real-time PCR assay to distinguish these pests based on two hydrolysis probes that bind to a segment of the internal transcribed spacer region 2 (ITS2 amplified using a single primer pair. One probe targets H. armigera, the second probe targets H. zea, and a third probe that targets a conserved segment of 18S rDNA is used as a control of DNA quality. The assay can be completed in 50 minutes when using isolated DNA and is successfully tested on larvae intercepted at ports of entry and adults captured during domestic surveys. We demonstrate that the assay can be run in triplex with no negative effects on sensitivity, can be run using alternative real-time PCR reagents and instruments, and does not cross react with other New World Heliothinae.

  19. Effect of zinc and phosphorus on dry matter yield, uptake and utilization of 65Zn on Maize (Zea Mays L.) grown in a molli-soil

    International Nuclear Information System (INIS)

    Zinc uptake and its utilization by Maize (Zea mays L.) variety Pragati using radiotracer 65Zn technique along with varying levels of phosphorus treatments on dry matter yield was studied. The gamma activity was measured by calibrated NaI(Tl) gamma ray spectrometer. It was observed that zinc uptake in treatment T2 found to be higher. However, treatment T6 showed good growth parameters and dry matter yield. The 65Zn activity was found maximum in roots and minimum in the leaves of maize plant. (author)

  20. Studies on the individual and combined diuretic effects of four Vietnamese traditional herbal remedies (Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus).

    Science.gov (United States)

    Doan, D D; Nguyen, N H; Doan, H K; Nguyen, T L; Phan, T S; van Dau, N; Grabe, M; Johansson, R; Lindgren, G; Stjernström, N E

    1992-06-01

    Herbal remedies are widely used in Vietnam alongside modern drugs. We assessed the diuretic effect of four traditional Vietnamese herbal remedies from Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus, all claimed to produce an increase of diuresis. No influence was recorded for the 12- and 24-h urine output or on the sodium excretion for any of the drugs when tested under standardized conditions in a placebo controlled double-blind crossover model. The present study indicates the need for critical review of the present recommendations regarding therapy with plant materials in countries relying on empiric traditions. PMID:1434681

  1. GENOTIPOS DE MAÍZ ( Zea mays L.) CON DIFERENTE CONTENIDO DE ACEITE Y SU RELACIÓN CON LA CALIDAD Y TEXTURA DE LA TORTILLA

    OpenAIRE

    María G. Vázquez-Carrillo; David Santiago-Ramos; Yolanda Salinas-Moreno; Julio López-Cruz; Ma Carmen Ybarra-Moncada; Alejandro Ortega-Corona

    2014-01-01

    La textura de las tortillas es un indicador fundamental de su calidad. La relación entre el contenido de aceite del gra - no de maíz ( Zea mays L.) y la textura de las tortillas es poco conocida; sin embargo, la presencia del aceite mejora signi - ficativamente la firmeza y masticabilidad de este alimento. El objetivo del presente estudio fue evaluar la composición química del grano de maíces con contenido diferente de aceite y determinar la relación entre el contenido de aceite y la calidad ...

  2. Movement and leaching losses of N-CO(15NH2)2 fertilizer in a alfisol under a corn crop (Zea mays, L.)

    International Nuclear Information System (INIS)

    In an oxid Paleudalf (Terra Roxa Estruturada) the nitrogen leaching losses are studied in a corn crop (Zea mays, L.) during one growing cycle (from 1979 October to 1980 February), through the study of soil water dynamics. The complete crop water balance is established using Hg manometer tensiometers. The variations of the NO-3-N concentration with the time and soil depth (60, 90 and 120cm) were followed by ceramic porous cup samples, some suggestions about the use of tensiometers and oil solutions samplers are presented, as well as, an apendice methodology used to determine the soil water conduction coefficients. (M.A.C.)

  3. Cell-wall properties contributing to improved deconstruction by alkaline pre-treatment and enzymatic hydrolysis in diverse maize (Zea mays L.) lines

    OpenAIRE

    Li, Muyang; Heckwolf, Marlies; Crowe, Jacob D.; Williams, Daniel L.; Magee, Timothy D.; Shawn M Kaeppler; Leon, Natalia de; Hodge, David B

    2015-01-01

    A maize (Zea mays L. subsp. mays) diversity panel consisting of 26 maize lines exhibiting a wide range of cell-wall properties and responses to hydrolysis by cellulolytic enzymes was employed to investigate the relationship between cell-wall properties, cell-wall responses to mild NaOH pre-treatment, and enzymatic hydrolysis yields. Enzymatic hydrolysis of the cellulose in the untreated maize was found to be positively correlated with the water retention value, which is a measure of cell-wall...

  4. Pyramiding the disease resistant genes to southern rust and stalk rot in maize(Zea mays L.) with marker-assisted selection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Southern corn rust(SCR) caused by Puccinia polysora Underw and maize stalk rot caused by Pythium inflatum Matthews(MSR-2) are two destructive diseases of maize(Zea mays L.) in China.Our previous studies indicated that maize inbred line Qi319 is highly resistant to SCR but susceptible to MSR-2,while inbred line 1145 is highly resistant to MSR-2 but susceptible to SCR.The SCR resistant gene(RppQ) in Qi319 and MSR-2 resistant gene(Rpi1) in 1145 have been mapped on chromosome 10 and 4 respectively.In this resea...

  5. Competencia entre Zea mays y Sorghum halepense por agua edáfica y su incidencia en el intercambio gaseoso foliar

    OpenAIRE

    Acciaresi, Horacio A.; Zuluaga, María S.; Yanniccari, Marcos E.; Guiamet, Juan J.

    2012-01-01

    La alta estabilidad productiva en ambientes con restricciones hídricas se ha vinculado a la habilidad de conservación del agua por parte de los cultivos. Sin embargo, diferentes especies de malezas, bajo competencia hídrica realizan un uso ineficiente de la misma. Con el objetivo de determinar la estrategia de consumo de agua que poseen Zea mays y Sorghum halepense bajo dos situaciones de disponibilidad hídrica edáfica y trabajando con plantas en contenedores, se estudió la evolución de los p...

  6. The effects of selenium and other micronutrients on the antioxidant activities and yield of corn (Zea mays L.) under drought stress

    OpenAIRE

    Sajedi, Nour Ali; Ardakani, Mohammad Reza; Madani, hamid; Naderi, Ahmad; Miransari, Mohammad

    2011-01-01

    The effects of selenium (Se) on plant growth under drought stress and in the presence of micronutrients are yet to be investigated. Hence, in a field experiment in 2007 the effects of Se and micronutrients including iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), boron (B) and molybdenum (Mo) were evaluated on corn (Zea mays L.) grain yield under drought stress. Main- and sub-plots were devoted to irrigation (control and water stressed at the eight-leaf, blister and grain filling stages) a...

  7. Soil water capture trends over 50 years of single-cross maize (Zea mays L.) breeding in the US corn-belt

    OpenAIRE

    Reyes, Andres; Messina, Carlos D.; Hammer, Graeme L.; Liu, Lu; van Oosterom, Erik; Lafitte, Renee; Cooper, Mark

    2015-01-01

    Breeders have successfully improved maize (Zea mays L.) grain yield for the conditions of the US corn-belt over the past 80 years, with the past 50 years utilizing single-cross hybrids. Long-term improvement for grain yield under water-limited conditions has also been reported. Grain yield under water-limited conditions depends on water use, water use efficiency, and harvest index. It has been hypothesized that long-term genetic gain for yield could be due, in part, to increased water capture...

  8. Peningkatan Bahan Organik Tanah dan pH tanah Ultisol Simalingkar B Melalui Perlakuan Bokashi dan Dolomit Terhadap Pertumbuhan dan Produksi Jagung (Zea mays L)

    OpenAIRE

    Yusnita, Wita

    2012-01-01

    A research entitled Organic Matter and Soil Acidity of Increasing on L Ultisol has been earned out at Simalingkar B, Kelurahan Kwala Bekala with Application of Bokashi and Dolomite on Growth and Production of " Corn (Zea mays L). It was done since February to July 2005. This research used a factorial Randomized Block Design consisting with 2 factors and 3 repetitions. The first factor included application of bokashi in 5 levels : BO (control), Bl (5 tons/Ha), B2 (10 tons/Ha), B3 (15 tons/H...

  9. Removal of Cd from Actual Soils Polluted with Cd and Zn and Cd-added Soils by Brassica juncea and Zea mays

    OpenAIRE

    Inoue, Hiromichi; Saeki, Kazutoshi

    2004-01-01

    We have alternated the 3-week cultivation of corn (Zea mays L.) and that of Indian mustard (Brassica juncea (L.) Czern) in a pot with the sequential rotation, corn-Indian mustard-corn-Indian mustard, in order to remove Cd from two actual soils polluted with Cd and Zn, one (low Cd) polluted (LP) containing 6.5mg Cd kg[-1] and 715mg Zn kg[-1] and another (high Cd polluted (HP)) with 13.6mg Cd kg[-1] and 836mg Zn kg[-1]. Fertilizer applications to soil in a rotational cropping can nihibit the ...

  10. Actividad antihipertensiva y antioxidante del extracto hidroalcohólico atomizado de Maíz morado (Zea mays L) en ratas

    OpenAIRE

    Jorge Arroyo; Ernesto Raez; Miguel Rodríguez; Víctor Chumpitaz; Jonny Burga; Walter De la Cruz; José Valencia

    2008-01-01

    Objetivos. Determinar la actividad antihipertensiva y antioxidante del extracto hidroalcohólico atomizado de Zea mays L. (maíz morado) en ratas con hipertensión arterial inducida. Materiales y métodos. Se utilizó cinco grupos de seis ratas Holtzmann cada uno, uno sin hipertensión (control negativo) y cuatro con hipertensión inducida por L-NAME: control positivo y tres grupos para las dosis de 250, 500 y 1000 mg/kg, respectivamente. El tratamiento se realizó por vía oral una vez por día durant...

  11. Efeitos do sistema de plantio e da consorciação soja-milho sobre artrópodes capturados no solo

    Directory of Open Access Journals (Sweden)

    Cividanes Francisco Jorge

    2002-01-01

    Full Text Available O objetivo deste estudo foi avaliar os efeitos do plantio direto e da consorciação soja [Glycine max (L. Merrill] e milho (Zea mays L. sobre artrópodes que vivem no solo. Os tratamentos constituíram um fatorial 3 x 2 (monocultura de soja, monocultura de milho, consorciação soja-milho x plantio direto, plantio convencional em blocos casualizados com quatro repetições; as amostragens foram efetuadas com armadilhas de solo, durante 1996 a 1998. Resultados estatisticamente significativos em pelo menos uma safra indicaram que o plantio direto foi favorável a predadores, como formigas (Brachymyrmex sp., Camponotus spp. e Ectatomma sp., carabídeos (Metius sp. e aranhas (Lycosidae. A consorciação soja-milho aumentou o número de Acrididae, enquanto a presença do milho favoreceu a ocorrência de Dermaptera em sistemas de consorciação soja-milho.

  12. Hábitos de consumo sobre la cerveza

    OpenAIRE

    Velasco Matilla, Débora

    2015-01-01

    Estudio de los hábitos de consumo de cerveza en un pueblo determinado situado en la provincia de Segovia, Cantalejo. Contiene un resumen sobre la historia de la cerveza y su tipología y un estudio de mercado sobre la cerveza partiendo de una encuesta. Grado en Comercio

  13. Violência sobre Crianças

    OpenAIRE

    Sacadura, Catarina Brito; Aragão, Maria José

    2014-01-01

    Trata-se de um estudo de revisão sobre a violência exercida sobre crianças, os agentes da violência, os sujeitos da violência, os factores de risco, as consequências na idade adulta e a recidividade de violência sexual.

  14. Algunas observaciones sobre el mundo actual

    OpenAIRE

    Tello, Ángel Pablo

    1993-01-01

    El artículo expone las nuevas condiciones políticas creadas en el mundo a partir de la caída del Muro de Brelín y la disolución de la Unión Soviética. Desde allí, el autor intenta reflexionar sobre las líneas de acción que emergen en el planeta como consecuencia de ello y de la ausencia de referencias globales que se observaron durante décadas. En particular, el ascenso de los nacionalismos que no sólo es un fenómeno que afecta a los países en desarrollo, sino también a las potencias industri...

  15. Algunas reflexiones sobre el turismo cultural

    Directory of Open Access Journals (Sweden)

    Claudia Toselli

    2006-01-01

    Full Text Available El presente artículo, si bien no pretende hacer un análisis exhaustivo sobre el turismo cultural, tiene por objetivo presentar algunas reflexiones acerca de esta modalidad turística desde diferentes aspectos. En primer lugar se abordará la relación entre turismo cultural y globalización, para luego centrarse en la incidencia de esta actividad como factor de desarrollo local y regional, haciendo referencia a algunos ejemplos de Argentina. Intentará también introducir acerca de los aspectos positivos y negativos, o puntos fuertes y débiles del turismo cultural. Y por último, esbozará algunas consideraciones acerca del rol de las organizaciones internacionales y de las principales agencias de cooperación internacional, incluyendo las resoluciones, declaraciones y recomendaciones más significativas en este campo del turismo.

  16. NOTAS SOBRE A LÓGICA ESTOICA

    Directory of Open Access Journals (Sweden)

    Valter Duarte Moreira Júnior

    2014-02-01

    Full Text Available Diante do grande desenvolvimento da Lógica e do cálculo proposicional no século XX, estudiosos do assunto em todo o mundo se concentraram em um rigoroso estudo dessa disciplina e sua história. Nesse processo, o eminente lógico polonês Jan Lukaziewicz descobriu em sua pesquisa sobre história da lógica a Lógica Estoica, que, já em III a. C., havia antecipado diversos métodos e conceitos da Lógica Moderna. Nossa intenção neste artigo é fazer um breve esboço da lógica desenvolvida pelos Estoicos.

  17. Reflexiones sobre el tratamiento ambulatorio de drogodependientes.

    Directory of Open Access Journals (Sweden)

    Juan Carlos González García

    1989-01-01

    Full Text Available Intentamos plantear algunas de las innumerables contradicciones, paradojas y mitos que se presentan en relación con las demandas y con las necesidades terapéuticas de los consumidores de drogas, desde el nivel de atención extrahospitalaria pública y dentro de una Unidad de Salud Mental. Se intenta reflexionar sobre los conocimientos teóricos y la realidad práctica, su interdependencia, complementariedad y divergencia, con la finalidad de evitar la huida asistencial o la omnipotencia terapéutica. Se valoran las diferencias existentes entre la farmacología teórica, anclada en el paradigma lewiniano, y la realidad clínica.

  18. Conceptos fundamentales sobre el mantenimiento de edificios

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    Juan Miguel Arencibia Fernández

    2007-01-01

    Full Text Available En esta investigación se realiza una profunda búsqueda sobre el tema del Mantenimiento de Edificios donde se abundan diferentes conceptos y criterios de la misma, encontrándose de esta forma los más utilizados métodos a emplear. Luego teniendo en cuenta las clasificación del Mantenimiento de Edificio según los tipos de obras, propietarios del inmueble y el momento que éste se realiza, como los costos de una edificación y su equipamiento a utilizar. Otros de los aspectos a tener en cuenta es la organización del Mantenimiento su planificación y responsabilidad, las ventajas que puede traer tanto para la economía y para el mismo usuario, como su vida útil, para el cual fueron ejecutadas las edificaciones.

  19. Sobre a moralidade do direito em Kant

    Directory of Open Access Journals (Sweden)

    Joãosinho Beckenkamp

    2009-07-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2009v8n1p63Na atual literatura sobre a fi losofi a prática de Kant há uma tendência a negligenciar a distinção feita na Metaphysik der Sitten entre direito (Jus e ética (Ethica, a ponto de ser a doutrina do direito de Kant vista como uma mera aplicação do imperativo categórico. Este artigo procura mostrar que Kant apresenta em sua doutrina do direito uma série de argumentos que logram estabelecer o direito de modo inteiramente independente da ética.

  20. Neruda e Drummond: um olhar sobre Stalingrado

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    Moacir Lopes de Camargos

    2015-07-01

    Full Text Available Este artigo tem por objetivo promover uma aproximação entre dois expoentes da lírica latino-americana do século XX, a saber: Pablo Neruda e Carlos Drummond de Andrade, a partir da análise dos poemas Canto a Stalingrado (1942 e Carta a Stalingrado (1943. Apresentaremos a visão histórica desses poetas sobre a Batalha de Stalingrado, considerada um dos principais eventos da Segunda Guerra Mundial. Ademais, será abordada a questão do engajamento político, que envolve a produção poética dos referidos autores.

  1. NOTAS SOBRE A LÓGICA ESTOICA

    OpenAIRE

    Valter Duarte Moreira Júnior

    2014-01-01

    Diante do grande desenvolvimento da Lógica e do cálculo proposicional no século XX, estudiosos do assunto em todo o mundo se concentraram em um rigoroso estudo dessa disciplina e sua história. Nesse processo, o eminente lógico polonês Jan Lukaziewicz descobriu em sua pesquisa sobre história da lógica a Lógica Estoica, que, já em III a. C., havia antecipado diversos métodos e conceitos da Lógica Moderna. Nossa intenção neste artigo é fazer um breve esboço da lógica desenvolvida pelos Estoicos....

  2. Apuntes sobre el Cultivo del Cacao

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    Ochoa Horacio

    1940-03-01

    Full Text Available Por muchos años permaneció el cultivo del cacao en nuestro país, en un deplorable atraso técnico; el agricultor a duras penas si tenía conocimientos generales de su explotación y, de una industria que tuvo su auge debido a la extensividad de las plantaciones, hoy sólo resta una reducida porción de ella. ¿Qué factores operaron esa tan notoria reducción hasta el punto de que exportadores en otros tiempos nos convertimos en importadores obligados de ese producto? Hay muchas razones de orden técnico y de orden económico. Los cacaotaleros obtenían halagadoras retribuciones cuando el jornal consistía en la alimentación que se le daba a la peonada y cuando, generoso, añadía una sobretasa en dinero. Bajo ese sistema de explotación, el descuadre que pudiera ocasionar tanto las enfermedades criptogámicas como los plagas, no era suficiente como para provocar el pesimismo en el hacendado y por tanto inducirlo al abandono de la plantación. A medida que las condiciones sociales del campesino se fueron modificando y su standard de vida aumentaba, cambió fundamentalmente el mecanismo de la industria Se observó entonces que los árboles morían y que era pobre la producción; que lo que en tiempos pasados fuera un negocio lucrativo, se les había convertido en una actividad improductiva y, para controlar estos fenómenos que se generalizaban en todas las zonas cacaotaleras, opusieron la ignorancia, el rutinarismo y la desidia. Lentamente se han ido modificando los conceptos antiguos sobre el trabajo cultural y los cuidados que con relación a las enfermedades y plagas requiere este delicado cultivo; la rutina está echando paso atrás y las experiencias científicas que procuran la prosperidad del plantío, se ponen en práctica en algunas zonas . Esto da esperanza para la reconstitución de la industria cacaotalera en nuestro país, que cuenta con inmensas regiones de óptima calidad para hacerla florecer sobre bases nuevas, con

  3. Sobre el Boletín

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    Andrés Arias

    2014-03-01

    Full Text Available En la página de Internet de la Biblioteca Luis Ángel Arango se indica que una de la funciones principales del Boletín es la de reseñar la novedades bibliográfica que van apareciendo en el país. "Novedades": de lo nuevo, tanto en las publicaciones como en las reseñas. Es decir, si lo que asegura la página de la Biblioteca es cierto, quien se acerca al Boletín debe encontrarse con comentarios recientes sobre libros recientes. Con guía que le ayuden a elegir entre las mil ofertas que hay en el mercado bibliográfico. Pero bien sabemos que este objetivo no se cumple.

  4. Aspectos da pesquisa sobre tipologia textual

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    Luiz Carlos Travaglia

    2014-03-01

    Full Text Available Este artigo chama a atenção dos pesquisadores sobre tipologiatextual, na área da Linguística Textual, sobre aspectos que sãoimportantes para que estas pesquisas gerem conclusões egeneralizações mais confiáveis. Os pontos comentados são: a anecessidade de uma teoria tipológica geral de textos que inclusivedetermine se as categorias de texto são todas da mesma natureza. Oautor propõe uma teoria geral; b a necessidade de estudos maishorizontalizados ou amplos que estabeleçam campos de pesquisa ede estudos mais verticalizados, que aprofundam o conhecimentode pontos específicos; c os aspectos metodológicos para superarproblemas no levantamento das categorias de texto existentes emuma sociedade e cultura, em suas diversas comunidades discursivase esferas de ação social; d a questão dos parâmetros e critérios paraconsiderar uma categoria de texto como sendo uma categoria e seela é de determinada natureza; e a questão dos critérios e parâmetrospara a caracterização das categorias de texto; f a necessidade deestudar as diversas relações de diferentes tipos que podem ocorrerentre as categorias de texto (de diferentes naturezas, tanto em suacomposição quanto em seu funcionamento sociodiscursivo; e g aatenção que merece a questão teminológica.

  5. Eficiencia de extractos vegetales como insecticida sobre Sitophilus zeamais en granos de maíz almacenados

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    Francisco de Assis Cardoso Almeida

    2014-01-01

    Full Text Available El Sitophilus zeamais es considerado la plaga más importante del maíz ( Zea mays L., almacenado en regiones tropicales y subtropicales. Con el objetivo minimizar los efectos indeseables de los insecticidas químicos sintéticos, el control de esa plaga con extractos vegetales viene convirtiéndose en una opción promisoria de bajo costo y segura para los aplicadores y consumidores. Fueron evaluadas en laboratorio la repelencia, atractividad y mortalidad del Sitophilus zeamais en granos de maíz tratados con polvos y extractos hidro alcohólico de Piper nigrum L. y Annona squamosa L. Para el estudio del polvo de los extractos de las plantas referidas anteriormente sobre la atractivi - dad y la repelencia de los insectos adultos, fue utilizada una arena con cinco cajas dispuestas diagonalmente, siendo la central conectada a las demás. En dos de los recipientes fueron colocadas muestras de maíz tratadas con el extracto en polvo y, en los dos otros recipientes el maíz no tratado y, en el recipiente central de la arena, 30 insectos no sexuados. Los extractos hidroalcohólico fueron obtenidos a partir del polvo de las semillas de esas especies, en percolador, con solvente alcohol etílico (70% v/v, los cuales fueron llevados a los insectos en la forma de vapor. El delineamiento experimental usado fue el completamente aleatorio con los tratamientos dispuesto en esquema factorial, en que los factores cuantitativos fueron revelados por la regresión en el análisis de la varianza. El porcentaje de repelencia fue del 86,75% con el polvo del extracto de Annona squamosa y del 79,25% con el Piper nigrum . Mortalidad del 100% fue lograda con el extracto de Annona squamosa y dosis de 5 mL y, 98% con el extracto de Piper nigrum en la dosis de 14 mL, indicando la influencia de la dosis y del extracto sobre la mor - talidad del Sitophilus zeamais adulto.

  6. Effects of Zinc Deficiency and Drought on Plant Growth and Metabolism of Reactive Oxygen Species in Maize (Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; JIN Ji-yun

    2007-01-01

    The combinative effects of applied zinc (Zn) and soil moisture on the plant growth, Zn uptake, and the metabolism of reactive oxygen species (ROS) in maize (Zea mays L.) plants were examined through two pot experiments under greenhouse conditions. Maize variety Zhongdan 9409 was used. In experiment 1, maize plants were grown in cumulic cinnamon soil with five Zn treatments (0, 3.0, 9.0, 27.0, and 81.0 mg Zn kg-1 soil). Three treatments of soil moisture including serious drought, mild drought, and adequate water supply were set at 30-35 %, 40-45 %, and 70-75 % (w/w) of soil saturated water content, respectively. Soil saturated water content was 36% (w/w). The dry matter weights of shoots were enhanced by Zn application and adequate water supply. There was no apparent difference in plant growth among Zn application rates from 3.0 to 81.0 mg Zn kg-1 soil. The increases of plant growth and Zn uptake due to Zn application were found more significant under well-watered condition than under drying condition. In experiment 2, two levels of Zn (0 and 5.0 mg Zn kg-1 soil) and soil moisture regimen (40-45 % and 70-75 % of soil saturated water content, respectively) were set. Zn deficiency or water stress resulted in higher concentrations of O2-· and malondiadehyde in the first fully expanded leaves.Zn deficiency lowered the activity of superoxide dismutase (SOD, EC 1.15.1.1) in leaves. Drought stress increased SOD activity in leaves regardless of Zn supply. The activity of guaiacol peroxidase (POD, EC1.11.1.11) was found to be enhanced by Zn supply only in well-watered leaves. Zinc deficiency or water stress had little effect on the activity of catalase (CAT, EC 1.11.1.6). The higher ROS level in early maize leaves due to water stress seemed not to be alleviated or lowered partially by Zn application. However, Zn fertilizer was recommended to apply to maize plants irrigated or supplied with adequate water, otherwise Zn deficiency would reduce the water use for plant biomass

  7. Ameliorative Effects of Brassinosteroid on Excess Manganese-Induced Oxidative Stress in Zea mays L.Leaves

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-hua; FENG Tao; PENG Xi-xu; YAN Ming-li; ZHOU Ping-lan; TANG Xin-ke

    2009-01-01

    Manganese (Mn) is becoming an important factor limiting crop growth and yields especially on acid soils.The present study was designed to explore the hypothesis that brassinosteroid application can enhance the tolerance of maize(Zea mays L.)to Mn stress and if so,whether or not the mechanism underlying involves regulation of antioxidative metabolism in leaves.The effects of 24-epibrassinosteroid(EBR)on the growth,photosynthesis,water status,lipid peroxidation,accumulation of reactive oxygen species,and activities or contents of antioxidant defense system in maize plants under Mn stress were investigated by a pot experiment.At supplemented Mn concentrations of 150-750 mg kg-1 soil,the growth of plants was inhibited in a concentration-dependent manner.The semi-lethal concentration was 550 mg Mn kg-1 soil.Foliage application with 0.1 mg L-1 EBR significantly reduced the decrease in dry mass,chlorophyll content,photosynthetic rate,leaf water content,and water potential of plants grown in the soil spiked with 550 mg kg-1 Mn.The oxidative stress caused by excess Mn,as reflected by the increase in malondialdehyde (MDA) content and lipoxygenase (LOX,EC 1.13.11.12) activity,accumulation of superoxide radical and H2O2,was greatly decreased by EBR treatment.Further investigations revealed that EBR application enhanced the activities ofsuperoxide dismutase (SOD,EC 1.15.1.1),peroxidase (POD,EC 1.11.1.7),catalase (EC 1.11.1.6),ascorbate peroxidase (APX,EC 1.11.1.11),dehydroascorbate reductase (DHAR,EC1.8.5.1),and glutathione reductase (GR,EC 1.6.4.2),and the contents of reduced ascorbate and glutathione,compared with the plants without EBR treatment.It iS concluded that the ameliorative effects of EBR on Mn toxicity are due to the upregulation of antioxidative capacity in maize under Mn stress.

  8. Field inoculation of arbuscular mycorrhiza on maize (Zea mays L. under low inputs: preliminary study on quantitative and qualitative aspects

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    Emilio Sabia

    2015-03-01

    Full Text Available Arbuscular mycorrhizal symbiosis contributes to the sustainability of soil-plant system. A field experiment was conducted to examine the effect of arbuscular mycorrhiza (AM on quantitative and qualitative performance in forage maize (Zea mays L.. Within the project Sviluppo di modelli zootecnici ai fini della sostenibilità (SOS-ZOOT a trial was conducted at the experimental farm of the Agricultural Research Council in Bella (PZ, located in Basilicata region (Southern Italy at 360 m asl, characterised by an annual rainfall of approximately 650 mm. For spring sowing, two plots of 2500 m2 were used, one sown with seeds inoculated with AM (M, 1.0 kg/ha, and the other one with non-inoculated seeds (NM. After 120 days after sowing, when plants showed 30% dry matter, five replicates of 1 m2 per plot were used to estimate dry matter yield (DMY, while half plot was dedicated to the assessment of grain production. For each replicate, three representative plants were considered; each plant was measured for height and was divided into leaves, stem and ear. For each plot, the following constituents were determined: crude protein, ash, ether extract, crude fibre (CF, fractions of fibre [neutral detergent (NDF, acid detergent fibre (ADF and sulphuric acid lignin] and phosphorus (P. Throughout the period of plants’ growth, no herbicides, organic or inorganic fertilisation, and irrigation water were distributed. The preliminary results revealed a significant effect of AM inoculation on forage maize DMY, P content in the whole plant, into the leaves and on the quality of steam. The M thesis showed a significant increase in terms of DMY in comparison with the NM thesis: 21.2 vs 17.9 t/ha (P<0.05. The mycorrhized whole plants [0.22 vs 0.17% dry matter (DM, P<0.05] and leaves (0.14 vs 0.09% DM, P<0.05 showed an increased P content. The stems of M plants showed a content of CF, NDF, ADF and Ash significantly lower compared with NM plants. No significant

  9. Stem characteristics of two forage maize (Zea mays L.) cultivars varying in whole plant digestibility. II. Relation between in vitro rumen fermentation characteristics and anatomical and chemical features within a single internode

    NARCIS (Netherlands)

    Boon, E.J.M.C.; Engels, F.M.; Struik, P.C.; Cone, J.W.

    2005-01-01

    Internode 7 of the stem of two forage maize (Zea mays L.) cultivars was studied anatomically and chemically at anthesis and subjected to fermentation tests in rumen fluid, using an automated gas production system. For anatomical studies internode 7 was sectioned at the top, middle and base. For chem

  10. Stem characteristics of two forage maize (Zea mays L.) cultivars varying in whole plant digestibility. IV. Changes during the growing season in anatomy and chemical composition in relation to fermentation characteristics of a lower internode

    NARCIS (Netherlands)

    Boon, E.J.M.C.; Struik, P.C.; Engels, F.M.; Cone, J.W.

    2012-01-01

    Improving digestibility of forage maize (Zea mays L.) through breeding is important to optimize the efficiency of ruminant's rations. It can partly be achieved by improving the digestibility of stem tissue, a genetically complex and diverse trait changing drastically during the growing season. We tr

  11. El puente Bendorf sobre el Rin (Alemania

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    Hirschfeld, Kurt

    1966-03-01

    Full Text Available This recently completed bridge over the Rhine is 524 m long, and is a reinforced concrete structure, built by successive overhangs, without the aid of formwork or scaffolding. The centre span is 208 m in length, and the other six vary between 43 and 71 m. The deck consists of two independent parts, including a continuous box girder, with a hinge at the crown of the main span. It is stiffened with transversal diaphragms, spaced every 34 m. The piles rest on pneumatic caissons, which go down to 16 m below the river bed. The attachment between the piles and the caissons is rigid, at the central pile, and at the other piles it operates through a roller bearing. The central span was constructed without intermediate supports for the first 40 m, and beyond that stage, for greater safety, a provisional movable tower was built, as a temporary point of support for the free overhang. The various sections were concreted and post-tensioned with 32 mm bars, by the Dywidag procedure. Account was taken of the varying deformations that took place at each section, so as to add the necessary counter-deflection that finally enabled the two sides of the arch to meet at the crown at the calculated point.Este puente, recientemente construido, sobre el Rin, tiene una longitud total de 524 m, es de hormigón armado y se ha realizado por el procedimiento de voladizos sucesivos, sin entramado auxiliar ni cimbras. La luz del tramo central es de 208 m, y las de los otros seis oscilan entre 43 y 71 m. La estructura del tablero se compone de dos partes independientes, formadas por una viga tipo cajón, continua, con una articulación en la clave del tramo central y rigidizada con diafragmas transversales espaciados a 34 m. Las pilas centrales se apoyan sobre cajones neumáticos que descienden 16 m debajo del fondo del río. La unión entre estas pilas y la estructura cajón es rígida, y de tipo rodillo en las otras pilas. El tramo central se ha construido por voladizos

  12. Algunas reflexiones sobre el poder itinerante almohade.

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    Maribel FIERRO

    2009-12-01

    Full Text Available La primera parte del artículo consiste en la presentación de dos estudios sobre el poder itinerante en el Magreb: Jocelyne Dakhlia (1988 para las épocas hafsí y posteriores; Manuela Marín (2005 sobre el caso almohade. En la segunda parte, primeramente se analiza la convergencia del itinerario de Ibn Tumart con las conquistas de ‘Abd al-Mu’min: el movimiento –real o legendario– del fundador mesiánico del imperio marca el territorio conquistado por su sucesor el califa y su presencia inserta el espacio en la memoria, la geografía y el poder imperiales. A continuación, se plantea la compleja cuestión de la «capitalidad» almohade: se puede hablar de una capital sagrada (Tinmal, una capital central (Marrakech, capitales regionales (Sevilla, Túnez y de una nueva capital inacabada (Rabat. Pero es la presencia (hadar del propio califa la que determina dónde está el centro del imperio.La première partie de cet article présente deux études sur le pouvoir itinérant au Mahgreb : celle de Jocelyne Dakhlia (1986 sur la période hafside et les suivantes, celle de Manuela Marín (2005 sur le cas almohade.Dans la seconde partie, on analyse d’abord la convergence de l’itinéraire d’Ibn Tumart avec les conquêtes d’‘Abd al-Mu’min : le  trajet – réel ou légendaire – du fondateur messianique de l’empire marque le territoire conquis par son successeur le calife et sa présence ancre l’espace dans la mémoire, la géographie et le pouvoir impériaux. Ensuite, on examine la question complexe de la « capitalité » almohade : on peut parler d’une capitale sacrée (Tinmal, d’une capitale centrale (Marrakech, de capitales régionales (Séville, Tunis et d’une nouvelle capitale inachevée (Rabat. Mais c’est la présence (hadar du calife lui-même qui détermine où est le centre de l’empire.

  13. Sobre la rehabilitación de la arquitectura

    OpenAIRE

    Iglesia Salgado, Félix de la

    2012-01-01

    El presente ensayo reflexiona sobre el papel actual de la técnica de la arquitectura ante determinadas estrategias y comportamientos urbanos que, volcadas sobre nuevas situaciones resultado del cambio cualitativo y cuantitativo que se produce en nuestras ciudades, proponen una nueva urbanidad; una búsqueda, a partir de la rehabilitación del tejido residencial y los espacios de relación, sobre el control de los nuevos lugares y formas de habitabilidad que se hacen visibles como partes de una r...

  14. Pilas de arena sobre grafos dirigidos y algo de complejidad

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    Carolina Mejía Moreno

    2006-01-01

    Full Text Available En este artículo estudiamos el Modelo de Pilas de Arena sobre grafos dirigidos. El comportamiento del modelo sobre grafos dirigidos es más complejo (en término estrictos que sobre grafos no dirigidos; es por ello que, para muchas de las preguntas centrales de la teoría, no se conoce la respuesta en el caso dirigido. En este artículo se ha sintetizado la teoría para digrafos, se han simplificado algunas pruebas y se concretan algunos resultados relacionados con la complejidad de predicción del autómata.

  15. Pistas para pensar las significaciones imaginarias sobre la invariancia

    OpenAIRE

    Bilyk, Pablo Andrés

    2011-01-01

    Este escrito propone un primer esbozo de nominalizaciones sobre las significaciones imaginarias en torno a la idea de invariancia, con el fin de comenzar a mapear categorías para transitar que nos permitan pensar las construcciones fantasmáticas sobre el no-cambio. En definitiva, se trata de avanzar sobre la problematización de los modos de funcionamiento, constitución y reconfiguraciones de las hegemonías en los entramados sociales contemporáneos.

  16. Effects of legume cover crop and sub-soiling on soil properties and Maize (Zea mays L) growth in semi arid area of Machakos district, Kenya = Efecto del cultivo de cobertua y el subsolado sobre las propiedades del suelo y crecimiento de maiz (Zea mays L.) en la region semi arida de Machakos, Kenia

    NARCIS (Netherlands)

    Karuma, A.; Gachene, C.K.K.; Gicheru, P.; Mwangombe, A.W.; Mwangi, H.W.; Clavel, D.; Verhagen, A.; Kaufmann, Von R.; Francis, J.; Ekaya, W.

    2011-01-01

    Low crop yields in the semi arid areas of Kenya have been attributed to, among other factors, low soil fertility, low farm inputs, labour constraints and inappropriate tillage practices that lead to pulverized soils. The aim of this study was to determine the effects of legume cover crops (LCC) on s

  17. Sobre a "conveniência" da escola

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    Marisa Vorraber Costa

    2009-01-01

    Full Text Available El artículo pretende mostrar un nuevo "uso" para la escuela, vinculado a la lógica de la etapa actual de la globalización en la que la cultura ocupa una posición singularmente importante, entrelazándose en la vida social, en los circuitos económicos y en los regímenes políticos. Recurriendo a la teorización de George Yúdice sobre los usos de la cultura en la era global, se analizan tres proyectos sociales - Você Apita, Tim Música nas Escolas y Escola Aberta - considerados expresivos de la forma como empresas, organizaciones públicas e iniciativas de la sociedad civil se articulan con la cultura y con la educación para hacer con que los mercados globalizados se muevan, pero no sólo en sus propios intereses, aunque ellos persistan en la cima de las prioridades. Hay indicios de que la "conveniencia" de la escuela sobrepasa el interés mercantil inmediato, y se proyecta como estrategia dirigida hacia una variada gama de propósitos socio-políticos, económicos y culturales. Entre ellos, la posibilidad de gobernar la vida de las personas, forjando visiones de mundo y de sociedad.

  18. sobre la población

    Directory of Open Access Journals (Sweden)

    Mauricio Schoijet

    2005-01-01

    Full Text Available En este artículo se analizan varios elementos de la obra de Thomas Malthus sobre población, en particular la recepción de su teoría y su posición política. Se resumen las críticas políticas, ideológicas y científicas que ha recibido, y se examinan asuntos hasta ahora no tratados por otros comentaristas, como es el caso de las excepciones admitidas por Malthus respecto al papel de las relaciones sociales feudales en la agricultura de Polonia y Rusia. Se sugiere que pese a que su teoría tendía a reforzar la pesada represión social y sexual existente, Malthus no fue apoyado por la burguesía británica (contrariamente a la apreciación de Marx. Se deduce que Malthus no percibió cabalmente los avances de la agricultura, y se refuta la tesis de Donald Winch de que habría sido un liberal de izquierda en política pues si bien en algunos aspectos se le puede considerar progresista, en otros, esenciales, conservador extremadamente represivo o protofascista, incluso precursor de la teoría de los golpes de Estado.

  19. Consideraciones sobre de la ética

    Directory of Open Access Journals (Sweden)

    Enrique Cantolla Bernal

    2005-12-01

    Full Text Available El presente ensayo muestra como el hombre, a través de la historia, a estado constantemente buscando beneficios para su vida y ha debido cumplir con varias tareas, que con el tiempo han dado origen a costumbres y comportamientos que han llevado a constituir la moral y la ética. Esta última, nos permite definir y determinar los principales fines de la vida del hombre y cuales son los principios y normas que lo rigen. Así, el estudio de la ética nos plantea la interrogante sobre "los fines de la vida en este mundo" y cuales son las conductas para conseguirlos. Sin embargo, el autor plantea que el hombre se enfrenta a la elección de valores alternativos y ante la interrogante de ¿cuál es el sumo bien del ser humano y de la sociedad?, han surgido diversas teorías que muestran como, casi todas las sociedades, han elegido la búsqueda de la felicidad como "el sumo bien", pero este concepto de "la felicidad" ha variando producto de las diversas teorías y doctrinas, que han emergido a lo largo de su historia.

  20. Apuntes sobre el Cultivo del Cacao

    Directory of Open Access Journals (Sweden)

    Chavarriaga. Eduardo

    1940-09-01

    Full Text Available El sombrío constituye uno de los problemas que se presentan en el cultivo del cacao, de necesaria resolución para ayuda del agricultor en su labor al producir tan importante grano. Contribuye a la economía del cultivo un conocimiento amplio de la cuestión que debe preocupar al productor inquiriendo no solamente por lo acostumbrado en la región, sino por lo que en otras partes se conoce sobre el particular, para abandonar un poco el emperismo y hacer una industria cada día más próspera. Como razón a favor del sombrío, tenemos los países en donde se produce cacao de fina calidad; Trinidad, Venezuela. Nicaragua, siempre acostumbran la sombra; y sin ir muy lejos, en el Valle del Cauca, donde no se cultiva a pleno sol y se obtienen plantaciones de larga duración y producto superior, es bien conocido el beneficio de ella; allí, los agricultores conocen los desastrosos efectos que ocasiona la falta de sombra, cuando por cualquier causa mueren los árboles que la suministran. Por tanto, en este estudio indicaremos el uso de la sombra para el cacao, como el medio de conservar la fertilidad y buenas condiciones del suelo, obtener buenos rendimientos y asegurar larga vida a la plantación.

  1. NOTAS SOBRE A IRRACIONALIDADE DA GUERRA

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    Edilene Leal

    2014-08-01

    Full Text Available Nesse artigo, procedemos a uma análise sobre a irracionalidade da guerra em tempos cada vez mais caracterizados pela evolução da racionalidade técnica, ou seja, em tempos contemporâneos. Esse é o ponto a partir do qual traçamos, aqui, um percurso argumentativo dividido em duas partes. Na primeira, reconstituímos elementos da concepção de guerra de filósofos como Maquiavel, Clausewitz e Kant, destacando, nos dois primeiros pensadores, a prerrogativa de que a guerra é racional quando se configura meio para fins políticos. Na segunda parte, confrontamos essa racionalidade política da guerra com a dupla dimensão técnica que a guerra assumiu: de um lado, a guerra como um fim em si mesmo e não mais como meio da ação política; de outro, a dimensão racionalizante da guerra como resultado do progresso técnico e científico, atualizada como guerra do terror.

  2. Cassirer e Sartre sobre o esclarecimento

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    Vinicius de Figueiredo

    2005-12-01

    Full Text Available O presente ensaio levanta alguns aspectos da estética no século XVIII. Partindo da apresentação de duas interpretações hoje clássicas sobre o assunto (a de Cassirer e a de Sartre, busca rever o pressuposto analítico comum a ambas, para, em seguida, apontar as conseqüências que a relação entre autor e público trazem para a compreensão de aspectos estilísticos que nos parecem centrais para a literatura do Esclarecimento.This paper aims at throwing some light on the Eighteenth-Century aesthetics. After examining two classical interpretations - Cassirer e Sartre's - concerning this subject, I argue that both authors share a common analytical pressupposition. My main purpose is to show that without taking account of the the relationship between author and public, we cannot understand some essential characteristics of the literature in the Enlightenment.

  3. Fechas y sospechas sobre Lucas de Tuy

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    Linehan, Peter

    2002-06-01

    Full Text Available The present essay seeks to establish what we know, as opposed to what we think we know, about the author of the Chronicon Mundi. Amongst the issues investigated are those of don Lucas's origins, the nature of his connections with León, the date of his activity as chronicler, and the use which may have been made of that work by D. Rodrigo Jiménez de Rada in the De rebus Hispaniae.

    El presente estudio busca establecer qué es lo que sabemos, en oposición a qué es lo que pensamos que sabemos, sobre el autor del Chronicon mundi. Entre los aspectos investigados están los orígenes de don Lucas de Tuy, la naturaleza de sus conexiones con León, la datación de su actividad como cronista así como el uso que pudiera haber hecho Rodrigo Jiménez de Rada de su obra en el De rebus Hispaniae.

  4. Consideraciones sobre diferentes procesos productivos y sus consecuencias sobre el medio ambiente

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    Caridad Ramos Alvariño

    2004-01-01

    Full Text Available En el presente trabajo se exponen algunas consideraciones sobre diferentes procesos productivos y sus consecuencias sobre el medio ambiente. La disminución del impacto negativo de algunas producciones sobre el medio ambiente es favorable, pero el problema va más allá y de lo que se trata es de la necesidad de una transformación sostenible de las producciones que puedan conducir a una vida agradable y una naturaleza conservada entre otras muchas cuestiones que agobian hoy al mundo. La solución al problema puede ser alcanzada con mayor prioridad en la reducci ón de la fuente primaria de la contaminación, seguida por el reciclaje y el desarrollo de tecnologías limpias. La reducción en la fuente se aplica por los cambios de productos y procesos. El cambio de la fuente se relaciona con la composición o el uso de los productos intermedios y finales, que reduzcan los residuos de producción, su uso o la disposición de los productos. Los cambios de procesos están relacionados con la sustitución de las materias primas de entrada, la modificación de las tecnologías y las mejoras operacionales. Las opciones específicas pueden incluir: el uso de materiales menos tóxicos, el aumento de la automatización, los procedimientos para las operaciones y el mantenimiento, el control de inventario, entre otros.

  5. Efecto de abonos verdes sobre la dinámica de hongos micorrizógenos (HMA) y bacterias nitrificantes en un ciclo de cultivo de maíz, Zea mays L.

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    Vergara Gómez, Andrés Felipe

    2013-01-01

    En un Humic dystrudepts localizado en zona de ladera de Palmira (Valle del Cauca - Colombia), caracterizado por alto contenido de materia orgánica y manejo agroecológico por aproximadamente ocho años se sembró Canavalia ensiformis L. y Axonopus scoparius como abonos verdes, el cual se cortó, mezcló y adicionó al suelo en etapa de prefloración de la leguminosa. Cuatro semanas después se estableció el cultivo de maíz bajo cinco tratamientos y tres repeticiones: Testigo (T), fertilización químic...

  6. PARTICIPACIÓN DEL NITRÓGENO DE LOS ABONOS VERDES EN LA NUTRICIÓN NITROGENADA DEL MAÍZ (Zea mays L.) CULTIVADO SOBRE SUELO FERRALÍTICO ROJO

    OpenAIRE

    Gloria M. Martín; Rivera, R

    2002-01-01

    El presente trabajo se realizó con el objetivo de estudiar la eficiencia del nitrógeno incorporado con los abonos verdes, utilizados como precedente en el cultivo del maíz en un suelo Ferralítico Rojo de La Habana. Para ello, se estudió el grado de participación de diferentes fuentes de nitrógeno (abonos verdes y fertilizante mineral) en la nutrición nitrogenada del maíz, mediante los métodos isotópico y de las diferencias. El experimento se condujo en condiciones de macetas (5 kg) y se estud...

  7. Riego y fertilización nitrogenada en maíz (zea mays l.): efecto sobre el rendimiento del cultivo y la contaminación subterránea por nitratos

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    Poch Massegú, Ricard

    2012-01-01

    Intensive farming often leads environmental consequences. This is the case of the study area of this thesis: the Empordà, a region with a variety of intensive crops (fruits, cereals, forage,...) and manifest problems of groundwater pollution by nitrates whose origin points also to agricultural practices in the area. The work has focusen on monoculture production of corn for grain with furrow irrigation and mineral nitrogen fertilization. Within this framework, objectives has been defined a...

  8. Normativa sobre el impuesto sobre los gases efecto hivernadero (Green house gases tax)

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    Rodrigo de Larrucea, Jaime

    2013-01-01

    Como dice el apartado V de la Exposición de motivos de la Ley 16/2013, se crea un nuevo impuesto sobre los gases de efecto invernadero, relativo a los gases fluorados que se utilizan habitualmente en numerosos sectores como refrigerantes, disolventes, agentes espumantes o agentes extintores de incendios, para paliar de alguna manera su negativa contribución al calentamiento de la atmósfera, con un potencial de calentamiento global mucho más elevado que el CO2.

  9. Algunas reflexiones acerca de la encuesta sobre trabajo colaborativo

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    Gargiulo, Sandra; Ponz, María Jimena

    2014-01-01

    Comenzamos el mes de noviembre con un nuevo tema del mes: Dinámicas de trabajo colaborativo virtual. Para ello, queremos compartir los resultados arrojados por la encuesta sobre el trabajo colaborativo que muchos de ustedes han completado.

  10. Reflexiones sobre el género y la censura

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    Daniel Cazés Menache

    2006-01-01

    Este trabajo analiza y reflexiona sobre la primera censura social: la censura genérica, es decir, la estructurada sobre la adscripción de género, arena en la que se sintetizan todas las censuras sociales destinadas a controlar a cada sujeto y a mantenerlo sometido a dominios de los que no podrá librarse ni para aceptarlos ni para ejercerlos.

  11. Banco Interamericano de Desarrollo informe sobre sostenibilidad 2011

    OpenAIRE

    Banco Interamericano de Desarrollo (BID)

    2012-01-01

    El Informe de Sostenibilidad contiene información sobre las contribuciones del BID a la sostenibilidad durante el año 2011. También proporciona información sobre las tendencias fundamentales del desarrollo y las dimensiones de sostenibilidad en América Latina y el Caribe. Este año, el informe se centra en la sostenibilidad y la agricultura en la región

  12. Effects of cytokinins on in vitro mineral accumulation and bud development in Annona glabra L. Efeito de citocininas sobre o acúmulo de minerais e desenvolvimento de brotações de Annona glabra L. in vitro

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    Lenaldo Muniz de Oliveira

    2010-12-01

    Full Text Available Annona glabra is a tropical species that has significant agronomic potential in terms of furnishing fruits for in natura consumption and for the production of phyto-pharmaceuticals. In vitro cultivation has been considered the most promising form of propagation for this species, although large scale utilization of this technique is currently limited by high rates of leaf abscission, reduced rates of explant multiplication and slow bud growth. The present work evaluated the effects of different cytokinins on mineral accumulation in shoots of A. glabra cultivated in vitro, and their effects on growth and survival of these plants. Buds of A. glabra were cultivated in Wood Plant Medium (WPM in the presence of 6-benzilaminopurine (BAP, thidiazuron (TDZ, kinetin (KIN, and zeatin (ZEA. KIN and BAP use resulted in the greatest growth, largest accumulation of dry mass and leaf area development, as well as the greatest survival rate during in vitro cultivation of this species. All cytokinins tested stimulated large accumulations of nitrogen and boron in shoots, but diminished levels of calcium as compared to controls.Annona glabra é uma espécie frutífera tropical que apresenta elevado potencial agronômico pelo fornecimento de frutos para o consumo in natura e pela produção de fitofármacos. O cultivo in vitro tem sido preconizado como a forma mais adequada de propagação para essa espécie, embora sua utilização em larga escala ainda seja limitada pela elevada taxa de abscisão foliar, reduzida taxa de multiplicação dos explantes e crescimento lento das brotações. Objetivou-se, neste trabalho, avaliar o efeito de citocininas sobre o acúmulo de minerais nas brotações de A. glabra cultivadas in vitro e seus reflexos sobre o crescimento e sobrevivência das plantas nesse tipo de ambiente. Brotações de A. glabra foram cultivadas em meio Wood Plant Medium (WPM, na presença de 6-benzilaminopurina (BAP, thidiazuron (TDZ, cinetina (KIN e

  13. PROTOCOLO DE KYOTO: DEBATE SOBRE AMBIENTE Y DESARROLLO EN LAS DISCUSIONES SOBRE CAMBIO CLIMÁTICO

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    Rodríguez S. Liliana

    2008-07-01

    Full Text Available El comportamiento climático del planeta y sus consecuencias han propiciado debates sobre los modelos de desarrollo de los países responsables del deterioro acelerado del ambiente y de los fenómenos naturales por estos días recurrentes. Sin embargo, países como Estados Unidos, luego de firmar compromisos como la Convención sobre Cambio Climático, rehúsan adquirir las obligaciones del Protocolo de Kyoto, por temor a sufrir deterioro en sus economías. En este escenario, donde la nación responsable de la emisión de aproximadamente 36% de los gases efecto invernadero resultado de la acción humana en el planeta no se compromete a adoptar políticas restrictivas tendientes a hacer sus modelos de producción más amigables con la naturaleza a pesar de que dichas medidas empiezan a ser impuestas a otras naciones como condicionantes en las negociaciones comerciales internacionales, parece ser que la adopción del Protocolo de Kyoto para países en desarrollo como Colombia no es del todo benéfica.

  14. EFEITO DE CALDAS SOBRE Corynespora cassiicola

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    Mercia Celoto

    2014-11-01

    Full Text Available The target spot (Corynespora cassiicola, main leaf disease occurred in barbados cherry in the regionof Junqueirópolis, SP, causing severe defoliates of plants. After the cleaning prune, producers apply line sulfhur in plants, for presenting fungicidal, insecticide and acaricide action. The objective of this study was to assess the effect of line sulfhur (75% and 3% - used by producers, bordeaux mixture (75% and „calda Viçosa‟ (75% on Corynespora cassiicola. The syrups were incorporate into potato-dextrose-agar or spore suspension for determination of inhibition of the mycelia growth and spores germination. Leaves barbados cherry, with symptoms of target spot, were treated with syrups. In wet champer, high humidity, was verified that sporulation occured in lesions, however the spores lost viability by presence of syrups in surface. In vitro, line sulfhur to 75% inhibited completely the mycelia growth of the fungus. Line sulfhur, Bordeaux mixture and „calda Viçosa‟ inhibited completely the spores germination. For the reasons, the use of syrups in barbados cherry, can contribute in reduction of souce of inoculum of the pathogen. A mancha alvo (Corynespora cassiicola é a principal doença da cultura da acerola, na região de Junqueirópolis, SP, causando desfolha precoce nas plantas. Após a realização da poda de limpeza anual, os produtores aplicam a calda sulfocálcica nas plantas, por apresentar ação fungicida, inseticida e acaricida. O objetivo deste trabalho foi avaliar em condições in vitro e in vivo o efeito das caldas sulfocálcica, bordalesa e Viçosa sobre Corynespora cassiicola. As caldas foram utilizadas nas seguintes concentrações: calda sulfocálcica (75 e 3% - concentração utilizada por produtores, calda Bordalesa (75% e calda Viçosa (75%. As caldas foram incorporadas em meio de batata-dextrose-ágar ou suspensão de esporos para determinação das inibições do crescimento micelial e da germinação de esporos

  15. Sobre o campo da Psicologia Social

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    Belinda Mandelbaum

    2012-03-01

    Full Text Available O campo da Psicologia Social é apresentado como território fértil, na contemporaneidade, para constituir-se como um laboratório para a produção em Ciências Humanas, uma vez que, no século XX, cada vez mais o social foi em direção ao psicológico. Neste campo, nosso embate dá-se no modo como entendemos o hífen pressuposto na integração psicossocial. A autora propõe que, entre o psicológico e o social, o hífen domina, pois ele é a própria essência relacional que é inerente a cada um dos elementos. Sugere que o modelo para entender o homem e suas circunstâncias proposto por Freud imbrica de forma indissociável o psicológico e o social, a ontogênese e a filogênese, com uma potência que teve impacto sobre todo o campo das Ciências Humanas. A Psicanálise é um instrumento hermenêutico para colaborar na elucidação dos fenômenos sociais. A autora utiliza imagens construídas por Freud e Walter Benjamin e poemas de Carlos Drummond de Andrade para fortalecer o entendimento do hífen psicossocial tanto em sua ação multidimensional quanto em sua organização.

  16. Construcciones en yeso proyectado sobre vegetales

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    Martínez, Hubert

    1986-07-01

    Full Text Available A construction method developed in early 1981 in Senegal, whose main objective is the evaluation of natural and human sources, specially those of wild vegetables and the phosphogypsum (a waste of chemical industry in Senegal. The introduction of the mechanical projection allows a noticeably growth in work performances and an improvement of the quality. The projection reduces de number of trades intervening in the work, doing away with plasters, watertightness systems and paintings, and simplifying the setting of technical installations and of carpentry. The acquisition of this projecting material is not very expensive, so, it is easy for small and medium enterprises to reach an expertness in gypsum work. Its finantial rentability is assured for a prize of the gypsum of 180% of the prize of the cement.Procedimiento de construcción desarrollado al comienzo de 1981 en el Senegal, teniendo como objetivo la valoración de las fuentes naturales y humanas, especialmente los vegetales en estado silvestre y el fosfoyeso, residuo de la industria química del Senegal. La introducción de la proyección mecánica permite aumentar sensiblemente el rendimiento del trabajo y mejorar la calidad. La proyección reduce el número de oficios que intervienen en la obra por la supresión de enlucidos, sistemas de estanquidad y pinturas sobre la gruesa obra y simplifica la colocación de las instalaciones técnicas y de carpintería. La adquisición del material de proyección, necesitando un capital relativamente modesto, se encuentra al alcance de pequeñas y medianas empresas que deseen especializarse en los trabajos de yeso. La rentabilidad financiera del procedimiento está asegurada para un precio del yeso de hasta el 180% del precio del cemento.

  17. Puente sobre el Rhin – Suiza

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    Bänziger, D. J.

    1972-10-01

    Full Text Available In the brief period of two months a new bridge over the Rhine has been constructed to substitute one which collapsed on August 1970, because of the undermining of one of its pillars. On November 28 1970 the new bridge was opened to the traffic, including trucks of up to 3.5 Kp, and on December 7th of the same year vehicles of up to 26 Kp could use it. In the construction of this bridge, for the first time, use has been made of cylindrical, prefabricated, precast thin shells. This project is of special significance because of its operational importance, since it connects Lichtenstein and Switzerland; the exceptionally short time of its construction; and the new type of deck used.Para sustituir un puente sobre el Rhin, hundido el 14 de agosto de 1970 por socavación de uno de sus pilares, se ha construido un nuevo puente en el escaso plazo de dos meses. El 28 de noviembre de 1970, este nuevo puente se abrió al tráfico de vehículos de hasta 3,5 Mp, y el 7 de diciembre del mismo año, a los vehículos de hasta 26 Mp. En la construcción de este puente se han utilizado, por vez primera, láminas cilíndricas de cubierta, prefabricadas y pretensadas. La importancia del puente, que sirve para el enlace entre el Principado de Liechtenstein y Suiza, el nuevo tipo de tablero utilizado, así como el plazo de construcción, extraordinariamente breve, dan un interés especial a esta obra.

  18. Perspectivas sobre la comunicación

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    María Luisa Naranjo Pereira

    2005-01-01

    Full Text Available Existen diversas teorías, enfoques y modelos de comunicación; de cada uno de ellos pueden rescatarse aspectos de gran valor para el logro de una comunicación eficaz. Este documento presenta una revisión de esos aspectos, para que se pueda comprender mejor y enriquecer uno de los procesos más importantes para el ser humano: el proceso de comunicación. Este es un ensayo en el cual se da a conocer la posición de la autora sobre el tema abordado. Se rescata el acento del enfoque humanista en la relación humana y en las etapas donde se desarrolla. A partir de la comunicación pragmática, se analizan los axiomas comunicacionales en que se fundamenta y lo que se conoce como patologías de esos axiomas. Además se revisan las principales características que distinguen la asertividad en la comunicación y las distintas formas de manipulación que la entorpecen. Del enfoque de Virginia Satir, se presentan los diversos aspectos de la comunicación, tanto funcional como disfuncional y los modelos de comunicación propuestos por esta autora. Se revisan aspectos importantes del enfoque de la comunicación educativa, tales como el control de la distancia, la voz y el cuerpo, las palabras y el situacional; así como los elementos que bloquean el proceso de comunicación y las sugerencias acerca de formas correctas de escuchar. Además, se hace referencia a la necesidad de emplear procesos educativos más holísticos y constructivistas y una comunicación-interrelación horizontal y con equidad.

  19. Sobre el genio de las mujeres

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    Valcárcel, Amelia

    1992-11-01

    Full Text Available Not available.

    A los varones, desde Tácito a Schopenhauer, nunca les ha parecido que las verdaderas mujeres son las que tienen en casa, sino las que tienen los otros varones (los germanos, los orientales. Por su parte, Wojtyla ha hecho profesión de fe «en el genio de las mujeres», reclutando enternecidos agradecimientos como el de Macciochi. La autora del presente artículo adopta una perspectiva histórica y una actitud analítica para aclarar qué es ese genio que como genérico nos adjudican. En primer lugar, la idea de genio es romántica y va emparejada con la de destino, sobre todo en el caso de los genios colectivos. Se trata de nociones que se construyen estipulativamente con fines pragmáticos y no admiten, por definición, contraejemplos. En el caso del genio de las mujeres, los llamados «valores femeninos» que lo constituyen pertenecen al ámbito de la Siulichkeit, y su eventual convalidación en el de la Moralitiit no puede obviar el proceso consistente en la crítica y el desmarcarse de una Sittlichkeit adjudicada como estereotipia que se contrasta, no con otra estereotipia simétrica, sino con lo universal, que se solapa con el genérico masculino. La autora, por último, nos recuerda que la fabricación de este genio que, a título de colectivo, se nos atribuye a las mujeres tiene lugar a costa de la usurpación de nuestra individualidad y de la ausencia de esquemas pragmáticos de reconocimiento de la genialidad individual que pueda producirse en el genérico femenino. Ahora bien: es esta última la que las mujeres necesitamos para poder romper con las tradiciones establecidas e instituir nuevos relatos.

  20. Estudio sobre encofrados de madera modernos

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    de la Peña Aznar, Juan M.

    1980-12-01

    Full Text Available The author continues the development of the subject «Modern Timber Formwork», by summing up the comparative examination —already carried out in Part III of this Study— of the different types of glued timber existing on the market. In addition, the loads and stresses allovk/able for coniferous timber and the proposal for establishing Regulations for the Timber Section of the Research and Experimental Forestry Institute of Spain are given. In part V of the author's Study, published in this article, the important subject of the glues used for joining timber, a truly vital point in order to obtain louvered timber beams which are simply glued together, is approached.

    El autor continúa el desarrollo del tema sobre «Encofrados de madera modernos», resumiendo el estudio comparativo —ya hecho en la Parte III de este Estudio— de las diferentes vigas de madera encolada existentes en el mercado dando, además, las cargas y tensiones admisibles para maderas coníferas y la propuesta de Reglamentación de la Sección de Maderas del Instituto Forestal de Investigaciones y Experiencias de España. En la parte V del Estudio del autor, publicada en este artículo, se aborda el importante tema de las colas empleadas para las uniones de madera, algo realmente vital para la obtención de vigas de madera en celosía simplemente encoladas.