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‣ Studying the genetic basis of drought tolerance in sorghum by managed stress trials and adjustments for phenological and plant height differences

Sabadin, P. K.; Malosetti, M.; Boer, M. P.; Tardin, F. D.; Santos, F. G.; Guimaraes, C. T.; Gomide, R. L.; Andrade, C. L. T.; Albuquerque, P. E. P.; Caniato, F. F.; Mollinari, M.; Margarido, G. R. A.; Oliveira, B. F.; Schaffert, R. E.; Garcia, A. A. F.; v
Fonte: SPRINGER; NEW YORK Publicador: SPRINGER; NEW YORK
Tipo: Artigo de Revista Científica
Português
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Managed environments in the form of well watered and water stressed trials were performed to study the genetic basis of grain yield and stay green in sorghum with the objective of validating previously detected QTL. As variations in phenology and plant height may influence QTL detection for the target traits, QTL for flowering time and plant height were introduced as cofactors in QTL analyses for yield and stay green. All but one of the flowering time QTL were detected near yield and stay green QTL. Similar co-localization was observed for two plant height QTL. QTL analysis for yield, using flowering time/plant height cofactors, led to yield QTL on chromosomes 2, 3, 6, 8 and 10. For stay green, QTL on chromosomes 3, 4, 8 and 10 were not related to differences in flowering time/plant height. The physical positions for markers in QTL regions projected on the sorghum genome suggest that the previously detected plant height QTL, Sb-HT9-1, and Dw2, in addition to the maturity gene, Ma5, had a major confounding impact on the expression of yield and stay green QTL. Co-localization between an apparently novel stay green QTL and a yield QTL on chromosome 3 suggests there is potential for indirect selection based on stay green to improve drought tolerance in sorghum. Our QTL study was carried out with a moderately sized population and spanned a limited geographic range...

‣ Manejo de cultivares de algodoeiro em densidade populacional variável com o uso de regulador de crescimento.; Management of cotton cultivars under variable plant densities using a plant growth regulator.

Zanon, Graciela Decian
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/11/2002 Português
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Com o objetivo de estudar o comportamento fenológico, morfológico e produtivo de cultivares de algodoeiro com diferentes arquiteturas de plantas em diferentes espaçamentos, através do manejo com regulador de crescimento, foi realizado o presente trabalho, na área experimental da ESALQ/USP, no município de Piracicaba, Estado de São Paulo, no ano agrícola de 2000/01. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas sub-subdivididas e 4 repetições. As parcelas constituíram-se dos espaçamentos de 0,76 e 1,01 m, as subparcelas das três cultivares (IAC 23, DeltaOpal e CD 401) e as sub-subparcelas em presença ou ausência de regulador de crescimento. Em seis plantas marcadas de cada parcela foram analisados os seguintes parâmetros: acompanhamento das fases fenológicas (emergência, aparecimento do primeiro botão floral, antese da primeira flor e abertura do primeiro capulho) e caracteres agronômicos de campo (altura de planta, diâmetro do caule, número de ramos vegetativos e frutíferos, conformação da planta, número de capulhos por planta e altura de inserção do primeiro ramo frutífero). Na área útil de cada parcela foi determinada, a produção de algodão em caroço por hectare e a precocidade de colheita. Em amostras de 20 capulhos tomadas aleatoriamente em cada parcela foram realizadas as análises dos caracteres agronômicos de laboratório (massa de 100 sementes...

‣ Espaçamentos e densidades populacionais em cultivares de algodoeiro com direfentes arquiteturas de plantas; Row spacing and plant population density for differentiated plant architecture cotton cultivars

Moreira, Raquel Capistrano
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/08/2008 Português
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O presente trabalho teve por objetivo avaliar diferentes espaçamentos entre linhas e densidades de plantas em três cultivares de algodoeiro com diferentes arquiteturas de plantas. Os experimentos foram conduzidos no ano agrícola 2005/2006 no Centro Experimental Central, do Instituto Agronômico, em Campinas-SP, no Pólo Regional do Noroeste Paulista, da APTA, em Votuporanga-SP e na Fazenda de Ensino e Pesquisa da Unesp, Campus de Ilha Solteira, em Selvíria-MS. O delineamento experimental utilizado foi em blocos ao acaso, em esquema fatorial 2x2x3, com 4 repetições, sendo dois espaçamentos entre linhas (0,45 e 0,90 m), duas densidades de semeadura (6 e 10 plantas.m-1) e três cultivares (IAC 24, DeltaOpal e Fibermax 966). Em cada parcela experimental foram tomadas 4 plantas ao caso e avaliadas as seguintes variáveis: altura final das plantas, altura de inserção do 1° ramo frutífero, diâmetro do caule, número de ramos reprodutivos e número de capulhos por planta. Em Votuporanga foram determinadas a incidência de podridão de maçãs e a espessura do pericarpo de maçãs jovens. Amostras de 20 capulhos foram colhidas em cada parcela experimental, para a avaliação dos componentes da produção: massa de um capulho, massa de 100 sementes e porcentagem de fibra (apenas no experimento de Campinas); e para as análises das características tecnológicas da fibra: comprimento...

‣ Estimativa do potencial de rendimento por estrato do dossel da soja, em diferentes arranjos de plantas; Yield potential estimated by soybean canopy stratum in response to plant arrangement

Rambo, Lisandro; Costa, Jose Antonio; Pires, Joao Leonardo Fernandes; Parcianello, Geovano; Ferreira, Felipe Gutheil
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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O potencial de rendimento da soja pode ser modificado pelo arranjo de plantas. Esta alteração pode resultar da contribuição diferenciada dos estratos do dossel para a determinação do potencial. O experimento foi conduzido na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul, RS, na estação de crescimento 2000/01, objetivando avaliar o potencial de rendimento em três estratos do dossel da soja em função da modificação do arranjo de plantas, em dois regimes hídricos. Utilizou-se a cultivar ‘BRS 137’, em semeadura direta. Os tratamentos constaram de níveis de irrigação (irrigado e não irrigado); espaçamentos entre linhas (20 e 40cm), e populações de plantas (20, 30 e 40 plantas m-2). Estimou-se o potencial de rendimento no início do enchimento de grãos (R5), admitindo-se que todas as flores se transformassem em legumes e que todos os legumes presentes neste estádio atingissem a maturação, formando grãos e contribuindo para o rendimento. O dossel foi divido em três estratos, por dois planos paralelos ao solo, determinando-se o potencial de rendimento e o rendimento de grãos nas três seções do dossel. O tratamento irrigado apresentou maior potencial de rendimento da planta inteira em R5 (14976kg ha-1) e rendimento de grãos em R8 (maturação) que o não irrigado (12148kg ha-1)...

‣ Characterization for plant height and flowering date in the biological species oat

Matiello, Rodrigo Rodrigues; Sereno, Maria Jane Cruz de Melo; Carvalho, Fernando Iraja Felix de; Barbosa Neto, Jose Fernandes; Pacheco, Marcelo Teixeira; Pegoraro, Diego Girardi; Taderka, Ivone
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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A utilização de raças silvestres em hibridações com o grupo cultivado em aveia (Avena sativa L.) tem sido fonte de incremento da variabilidade genética. Desta forma, o presente trabalho foi desenvolvido com o objetivo de identificar e caracterizar a variabilidade genética dos caracteres morfofisiológicos estatura de planta e dias da emergência à floração em grupos de genótipos cultivados de aveia, introduções silvestres de A. fatua L., e em populações segregantes dos cruzamentos naturais de A. sativa x A. fatua. Ampla variabilidade genética foi revelada para os caracteres avaliados tanto dentro como entre os grupos. O grupo silvestre A. fatua demonstrou plantas de elevada estatura e precoces. Foi possível encontrar populações segregantes de A. sativa x A. fatua com reduzida estatura e precocidade. As introduções silvestres de A. fatua avaliadas neste trabalho podem ser utilizadas em programas de melhoramento para incrementar a variabilidade genética, pela transferência de caracteres específicos para o germoplasma cultivado.; The use of wild oat races in artificial hybridization with cultivated oat (Avena sativa L.) has been used as a way of increasing the variability. This work aimed to identify the variability for plant height and flowering date of groups of cultivated oat genotypes...

‣ The field resistance of potato cultivars to foliar late blight and its relationship with foliage maturity type and skin type in Brazil

Duarte, H. S. S.; Zambolim, L.; Mizubuti, E. S. G.; Padua, J. G.; Ribeiro Junior, J. I.; Carmo, E. L.; Nogueira Junior, A. F.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 139-155
Português
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); The use of resistant cultivars is the preferred control method for plant diseases. This approach is attractive owing to its high efficacy, low cost, and ease of implementation. This work aimed to assess the resistance of potato cultivars to foliar late blight (Phytophthora infestans) under different environmental conditions. It further aimed to assess the relationships between resistance to foliar late blight and foliage maturity type and between resistance to foliar late blight and the skin type of the potato. Three experiments were performed in two different regions of the state of Minas Gerais with different environmental conditions. The first and second experiments used 34 cultivars (treatments). The third experiment used 17 cultivars. The severity of foliar late blight in each plot was quantified every 2 days using a descriptive scale. The values of the epidemiological variables were then calculated. The proposed levels of resistance to foliar late blight were defined as: resistant (R), moderately resistant (MR), moderately susceptible (MS) and susceptible (S). The majority of potato cultivars were susceptible to foliar late blight. The resistance levels of some cultivars to foliar late blight used in these experiments changed according to the pathogen population and environmental conditions. The cultivars with the highest levels of resistance to foliar late blight (resistant and moderately resistant) were later maturity. Most cultivars that have been classified as moderately susceptible or susceptible were earlier maturity. In general...

‣ Estádio de Desenvolvimento do Milho. 2. Efeito sobre o Consumo e a Digestibilidade da Silagem em Ovinos

Lavezzo, OENM; Lavezzo, W.; deSiqueira, E. R.
Fonte: Revista Sociedade Brasileira Zootecnia Publicador: Revista Sociedade Brasileira Zootecnia
Tipo: Artigo de Revista Científica Formato: 683-690
Português
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Corn plants were ensiled at the milk, milk-early dough, medium dough, and semi-hard dough stages. The intake and digestibility trials showed that: a) silage DM and NFE contents increased and ADF, cellulose, and lignin contents decreased with plant maturity; b) corn plant maturity had little effect on the digestibility of the silages, but the milk and medium dough stages produced the best results; c) no consistent effect of maturity was observed in DM and CP daily intakes (mean values 41.86 and 26.77/g/kg(75), respectively). Nevertheless, daily digestible dry matter and digestible protein intakes (g/kg(75)) were higher with medium-dough grains (31.74 and 1.97g, respectively) than with the milk (23.27 and 1.45g, respectively) and the milk-early dough stages (22.60 and 1.28g, respectively). However, similar intakes were observed with the medium-dough and semi-hard dough stages. Total digestible nutrient contents of the silages were affected little by corn plant maturity. Nevertheless, statistical differences were Found between the medium dough (70.09%) and the milk-early dough stages (63.07%).

‣ Characterization for plant height and flowering date in the biological species oat

Matiello,Rodrigo Rodrigues; Sereno,Maria Jane Cruz Mello; Barbosa Neto,José Fernandes; Carvalho,Fernando Irajá Félix de; Pacheco,Marcelo Teixeira; Pegoraro,Diego Girardi; Taderka,Ivone
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/1999 Português
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The use of wild oat races in artificial hybridization with cultivated oat (Avena sativa L.) has been used as a way of increasing the variability. This work aimed to identify the variability for plant height and flowering date of groups of cultivated oat genotypes, wild introductions of A. fatua L. and segregating populations of natural crosses between A. sativa and A. fatua. Wide genetic variability was observed for both traits in the groups and between them. The wild group of A. fatua L. showed high plants with early maturity, but in the segregating group there was reduced plant height and early maturity. The wild introductions of A. fatua L. studied in this work can be used in oat breeding programs to increase genetic variability by transferring specific characters into the cultivated germ plasm.

‣ Morphological, physicochemical and sensory evaluation of celery harvested from early to late maturity

Yommi,Alejandra Karina; Di Gerónimo,Natalia Marcela; Carrozzi,Liliana Esther; Quillehauquy,Victoria; Goñi,María Gabriela; Roura,Sara Inés
Fonte: Associação Brasileira de Horticultura Publicador: Associação Brasileira de Horticultura
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 Português
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The aim of this study was to determine quality changes in petioles of self-blanching celery (Apium graveolens), cv. Golden Boy, harvested at 80, 87, 94, 101, 108, 115, 122 and 129 days after-transplanting (DAT). Total weight (TW), total length (TL), number of leaves per plant (LN) and by plant zone (external, LNZ E; middle, LNZ M; internal, LNZ I), and petiole length (PL) were evaluated at each harvest time. Petioles quality of each zone in the plant were analyzed in terms of: color (hue angle), texture (cutting force), total soluble solids content (TSS) and titratable acidity (TA). The petioles also were sensorially evaluated by descriptive analysis considering visual characteristics (flexibility, hollowness), flavor (typical flavor and odor) and texture attributes (hardness, crunchiness, juiciness and fibrousness). From 80 to 129 DAT, TW and TL increased 33 g/DAT and 0.62 cm/DAT, respectively. Leaves development was detected until the 122 DAT; LNZ I grew to a greater extent. The PL increased during plant development, mainly in middle and internal leaves; being the middle leaves the longest. Hue angle and cutting force were similar in external and middle petioles and both resulted higher than internal ones until the 122 and 115 DAT...

‣ UNDERSTANDING PLANT DENSITY EFFECTS ON MAIZE GROWTH AND DEVELOPMENT: AN IMPORTANT ISSUE TO MAXIMIZE GRAIN YIELD

Sangoi,Luís
Fonte: Universidade Federal de Santa Maria Publicador: Universidade Federal de Santa Maria
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2001 Português
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Maize is the agronomic grass species that is most sensitive to variations in plant density. For each production system, there is a population that maximizes grain yield. This article presents an overview of the factors that affect optimum plant population, emphasizingthe effects of dense stands on ear development and discussing important changes in plant traits that have contributed to increase the tolerance of modern hybrids to high plant densities. Population for maize maximum economic grain yield varies from 30,000 to over 90,000pl.ha-1, depending on water availability, soil fertility, maturity rating, planting date and row spacing. When the number of individuals per area is increased beyond the optimum plant density, there is a series of consequences that are detrimental to ear ontogeny and result in barrenness. First, ear differentiation is delayed in relation to tassel differentiation. Later-initiated earshoots have a reduced growth rate, resulting in fewer spikelet primordia transformed into functional florets by the time of flowering. Functional florets extrude silks slowly, decreasing the number of fertilized spikelets due to the lack of synchrony between anthesis and silking. Limitations in carbon and nitrogen supply to the ear stimulate young kernel abortion immediately after fertilization. Availability of earlier hybrids...

‣ Influence of Sulfur Deficiency on the Expression of Specific Sulfate Transporters and the Distribution of Sulfur, Selenium, and Molybdenum in Wheat1

Shinmachi, Fumie; Buchner, Peter; Stroud, Jacqueline L.; Parmar, Saroj; Zhao, Fang-Jie; McGrath, Steve P.; Hawkesford, Malcolm J.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Português
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Interactions between sulfur (S) nutritional status and sulfate transporter expression in field-grown wheat (Triticum aestivum) were investigated using Broadbalk +S and −S treatments (S fertilizer withheld) at Rothamsted, United Kingdom. In 2008, S, sulfate, selenium (Se), and molybdenum (Mo) concentrations and sulfate transporter gene expression were analyzed throughout development. Total S concentrations were lower in all tissues of −S plants, principally as a result of decreased sulfate pools. S, Se, and Mo concentrations increased in vegetative tissues until anthesis, and thereafter, with the exception of Mo, decreased until maturity. At maturity, most of the S and Se were localized in the grain, indicating efficient remobilization from vegetative tissues, whereas less Mo was remobilized. At maturity, Se and Mo were enhanced 7- and 3.7-fold, respectively, in −S compared with +S grain, while grain total S was not significantly reduced. Enhanced expression of sulfate transporters, for example Sultr1;1 and Sultr4;1, in −S plants explains the much increased accumulation of Se and Mo (7- and 3.7-fold compared with +S in grain, respectively). Sultr5;2 (mot1), thought to be involved in Mo accumulation in Arabidopsis (Arabidopsis thaliana)...

‣ Comparative transcript profiling by SuperSAGE identifies novel candidate genes for controlling potato quantitative resistance to late blight not compromised by late maturity

Draffehn, Astrid M.; Li, Li; Krezdorn, Nicolas; Ding, Jia; Lübeck, Jens; Strahwald, Josef; Muktar, Meki S.; Walkemeier, Birgit; Rotter, Björn; Gebhardt, Christiane
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 14/11/2013 Português
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Resistance to pathogens is essential for survival of wild and cultivated plants. Pathogen susceptibility causes major losses of crop yield and quality. Durable field resistance combined with high yield and other superior agronomic characters are therefore, important objectives in every crop breeding program. Precision and efficacy of resistance breeding can be enhanced by molecular diagnostic tools, which result from knowledge of the molecular basis of resistance and susceptibility. Breeding uses resistance conferred by single R genes and polygenic quantitative resistance. The latter is partial but considered more durable. Molecular mechanisms of plant pathogen interactions are elucidated mainly in experimental systems involving single R genes, whereas most genes important for quantitative resistance in crops like potato are unknown. Quantitative resistance of potato to Phytophthora infestans causing late blight is often compromised by late plant maturity, a negative agronomic character. Our objective was to identify candidate genes for quantitative resistance to late blight not compromised by late plant maturity. We used diagnostic DNA-markers to select plants with different field levels of maturity corrected resistance (MCR) to late blight and compared their leaf transcriptomes before and after infection with P. infestans using SuperSAGE (serial analysis of gene expression) technology and next generation sequencing. We identified 2034 transcripts up or down regulated upon infection...

‣ Plant growth and phenolic compounds in the rhizosphere soil of wild oat (Avena fatua L.)

Iannucci, Anna; Fragasso, Mariagiovanna; Platani, Cristiano; Papa, Roberto
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 17/12/2013 Português
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The objectives of this study were to determine the pattern of dry matter (DM) accumulation and the evolution of phenolic compounds in the rhizosphere soil from tillering to the ripe seed stages of wild oat (Avena fatua L.), a widespread annual grassy weed. Plants were grown under controlled conditions and harvested 13 times during the growing season. At each harvest, shoot and root DM and phenolic compounds in the rhizosphere soil were determined. The maximum DM production (12.6 g/plant) was recorded at 122 days after sowing (DAS; kernel hard stage). The increase in total aerial DM with age coincided with reductions in the leaf/stem and source/sink ratios, and an increase in the shoot/root ratio. HPLC analysis shows production of seven phenolic compounds in the rhizosphere soil of wild oat, in order of their decreasing levels: syringic acid, vanillin, 4-hydroxybenzoic acid, syringaldehyde, ferulic acid, p-cumaric acid and vanillic acid. The seasonal distribution for the total phenolic compounds showed two peaks of maximum concentrations, at the stem elongation stage (0.71 μg/kg; 82 DAS) and at the heading stage (0.70 μg/kg; 98 DAS). Thus, wild oat roots exude allelopathic compounds, and the levels of these phenolics in the rhizosphere soil vary according to plant maturity.

‣ Whole plant acclimation responses by finger millet to low nitrogen stress

Goron, Travis L.; Bhosekar, Vijay K.; Shearer, Charles R.; Watts, Sophia; Raizada, Manish N.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 19/08/2015 Português
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The small grain cereal, finger millet (FM, Eleusine coracana L. Gaertn), is valued by subsistence farmers in India and East Africa as a low-input crop. It is reported by farmers to require no added nitrogen (N), or only residual N, to produce grain. Exact mechanisms underlying the acclimation responses of FM to low N are largely unknown, both above and below ground. In particular, the responses of FM roots and root hairs to N or any other nutrient have not previously been reported. Given its low N requirement, FM also provides a rare opportunity to study long-term responses to N starvation in a cereal species. The objective of this study was to survey the shoot and root morphometric responses of FM, including root hairs, to low N stress. Plants were grown in pails in a semi-hydroponic system on clay containing extremely low background N, supplemented with N or no N. To our surprise, plants grown without deliberately added N grew to maturity, looked relatively normal and produced healthy seed heads. Plants responded to the low N treatment by decreasing shoot, root, and seed head biomass. These declines under low N were associated with decreased shoot tiller number, crown root number, total crown root length and total lateral root length...

‣ Development of a molecular marker linked to late maturity α-amylase (LMA) in wheat; Development of a molecular marker linked to late maturity alpha-amylase (LMA) in wheat

Carter, M.; Mrva, K.; Mares, D.; Wilson, R.; Barclay, I.; Appels, R.; Jones, M.
Fonte: Australasian Plant Breeding Association Publicador: Australasian Plant Breeding Association
Tipo: Conference paper
Publicado em //2002 Português
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Late maturity α−amylase (LMA) refers to the synthesis of α−amylase activity, which occurs under particular environmental conditions during the later stages of grain ripening in some genotypes in the absence of rain or sprouting. Grain affected by LMA may have a sound appearance, but because of the high α−amylase activity can be unsuitable for a range of end-product applications. Screening for LMA in wheat cultivars is difficult due to the influence of the environment on the expression of this trait. Therefore, the development of a molecular marker to .tag. this trait for marker assisted selection in wheat breeding programs would be a definite advantage. Bulked segregant analysis (BSA) and fluorescent amplified fragment length polymorphism (AFLP) technologies were used to identify loci linked to LMA in a doubled haploid population derived from wheat (Triticum aestivum L. em. Thell) cultivars Cleo-Inia (LMA source) and Janz (non-LMA). Markers linked to LMA were identified in bulks developed from 10 LMA and 10 non-LMA plants, converted to PCR based markers using radioactive AFLP and validated on other cultivars with known LMA phenotype.

‣ Genetic, hormonal, and physiological analysis of late maturity α-amylase in wheat; Genetic, hormonal, and physiological analysis of late maturity alpha-amylase in wheat

Barrero, J.; Mrva, K.; Talbot, M.; White, R.; Taylor, J.; Gubler, F.; Mares, D.
Fonte: Amer Soc Plant Physiologists Publicador: Amer Soc Plant Physiologists
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
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Late maturity α-amylase (LMA) is a genetic defect that is commonly found in bread wheat (Triticum aestivum) cultivars and can result in commercially unacceptably high levels of α-amylase in harvest-ripe grain in the absence of rain or preharvest sprouting. This defect represents a serious problem for wheat farmers, and apart from the circumstantial evidence that gibberellins are somehow involved in the expression of LMA, the mechanisms or genes underlying LMA are unknown. In this work, we use a doubled haploid population segregating for constitutive LMA to physiologically analyze the appearance of LMA during grain development and to profile the transcriptomic and hormonal changes associated with this phenomenon. Our results show that LMA is a consequence of a very narrow and transitory peak of expression of genes encoding high-isoelectric point α-amylase during grain development and that the LMA phenotype seems to be a partial or incomplete gibberellin response emerging from a strongly altered hormonal environment.; Jose M. Barrero, Kolumbina Mrva, Mark J. Talbot, Rosemary G. White, Jennifer Taylor, Frank Gubler, and Daryl J. Mares

‣ Whole-genome mapping of agronomic and metabolic traits to identify novel quantitative trait loci in bread wheat grown in a water-limited environment

Hill, C.; Taylor, J.; Edwards, J.; Mather, D.; Bacic, A.; Langridge, P.; Roessner, U.
Fonte: Amer Soc Plant Physiologists Publicador: Amer Soc Plant Physiologists
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
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Drought is a major environmental constraint responsible for grain yield losses of bread wheat (Triticum aestivum) in many parts of the world. Progress in breeding to improve complex multigene traits, such as drought stress tolerance, has been limited by high sensitivity to environmental factors, low trait heritability, and the complexity and size of the hexaploid wheat genome. In order to obtain further insight into genetic factors that affect yield under drought, we measured the abundance of 205 metabolites in flag leaf tissue sampled from plants of 179 cv Excalibur/Kukri F1-derived doubled haploid lines of wheat grown in a field experiment that experienced terminal drought stress. Additionally, data on 29 agronomic traits that had been assessed in the same field experiment were used. A linear mixed model was used to partition and account for nongenetic and genetic sources of variation, and quantitative trait locus analysis was used to estimate the genomic positions and effects of individual quantitative trait loci. Comparison of the agronomic and metabolic trait variation uncovered novel correlations between some agronomic traits and the levels of certain primary metabolites, including metabolites with either positive or negative associations with plant maturity-related or grain yield-related traits. Our analyses demonstrate that specific regions of the wheat genome that affect agronomic traits also have distinct effects on specific combinations of metabolites. This approach proved valuable for identifying novel biomarkers for the performance of wheat under drought and could facilitate the identification of candidate genes involved in drought-related responses in bread wheat.; Camilla B. Hill...

‣ Compost effects on soil water content, plant growth under drought and nutrient leaching.

Nguyen, Trung Ta
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2013 Português
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Compost is increasingly used in agriculture as a soil conditioner and fertilizer to improve soil properties and crop production by replenishing soil organic matter and supplying nutrients and thereby improving soil physical, chemical and biological properties. However, little is known about the effect of compost on soil water content and plant growth under water deficit stressed condition and if clay added to compost or soil influences nutrient leaching from compost. This thesis includes pot, field and laboratory incubation studies with the following aims (1) to assess the effects of compost on water availability to plants and gas exchange under well-watered and drought stressed conditions, (2) to study the long term effect of mulched compost after a single application, (3) to compare effects of incorporated and mulched compost on soil water content, nutrient uptake and plant growth, and (4) to determine the effect of clay added to compost or sandy soil on nutrient availability and leaching. To assess the effects of compost on plant growth under water-limiting conditions, two pot experiments were conducted; one with tomato and the second with capsicum. Tomatoes (Lycopersicon esculentum L.) were grown in pots were grown in a sandy soil without or with mulched or incorporated compost from garden and food waste to assess water availability to plants and plant physiology under well-watered and drought stressed conditions. Both mulch and incorporated compost increased plant growth with the greater effect by incorporated compost...

‣ Amadurecimento do mamão 'Golden': ponto de colheita, bloqueio da ação do etileno e armazenamento refrigerado; Ripening of ‘Golden’ papaya fruit: harvest time, ethylene action blockade and cold storage

Bron, Ilana Urbano
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 22/05/2006 Português
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O presente trabalho objetivou estudar como o ponto de colheita, o bloqueio da ação do etileno e o armazenamento refrigerado interferem no amadurecimento e na qualidade do mamão ‘Golden’. No primeiro experimento, foram colhidos mamões ‘Golden’ em 4 estádios de maturação (Estádio 0: totalmente verde; Estádio 1: até 15% da casca amarela; Estádio 2: 16-25% da casca amarela; Estádio 3: 26-50% da casca amarela) e analisados, durante o amadurecimento a 23ºC, quanto às características físicas e químicas (cor da casca, firmeza da polpa, sólidos solúveis, acidez titulável e ácido ascórbico), fisiológicas (respiração e produção de etileno) e sensoriais (sabor, odor, firmeza e aparência). A partir do 2º dia de armazenamento a 23ºC, os frutos apresentaram respiração constante ao redor de 31 mL CO2 kg-1 h-1 para os estádios 0, 1 e 2 e de 37 mL CO2 kg-1 h-1 para o estádio 3. Não foi observado típico comportamento climatérico para nenhum dos estádios. Somente frutos colhidos nos estádios 0 e 1 apresentaram pico na produção de etileno de 2,1 µL C2H4 kg-1 h-1 aos 7 dias e 1,3 µL C2H4 kg-1 h-1 aos 6 dias de armazenamento a 23ºC, respectivamente. Frutos colhidos nos estádios 2 e 3 tiveram notas superiores na avaliação sensorial...

‣ Ripening and quality of 'Golden' papaya fruit harvested at different maturity stages

Bron,Ilana U.; Jacomino,Angelo P.
Fonte: Brazilian Journal of Plant Physiology Publicador: Brazilian Journal of Plant Physiology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 Português
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The objective of this study was to determine how ripening physiology and quality of 'Golden' papaya are affected by maturity stages at harvest. Papayas were harvested at four maturity stages (Stage 0: totally green; Stage 1: up to 15% of yellow skin; Stage 2: 16-25% of yellow skin; Stage 3: 26-50% of yellow skin) and evaluated during ripening at 23ºC. Physical and physico-chemical (skin color, pulp firmness, soluble solids, titratable acidity, and ascorbic acid), physiological (respiratory activity and ethylene production), and sensorial (flavor, odor, firmness, and appearance) characteristics were evaluated. Regardless of maturity stages, fruit showed similar variation in respiration rate, exhibiting constant values after the 2nd day of storage at 23ºC (~31 mL CO2 kg-1 h-1 for stages 0, 1, and 2, and ~37 mL CO2 kg-1 h-1 for stage 3). Typical climacteric behavior was not observed for any maturity stage. Only fruit harvested at stage 0 and 1 showed a well defined ethylene production peak of 2.1 µL C2H4 kg-1 h-1 after 7 d of storage and 1.3 µL C2H4 kg-1 h-1 after 6 d, respectively. Fruit harvested at stages 0, 1, 2 and 3 reached the edible condition (pulp firmness < 20 N) after 7, 6, 4, and 3 d at 23ºC, respectively. The ascorbic acid concentration increased 20-30% during ripening...