ABSTRACT The objective of this study was to evaluate whether the inhibition of gibberellin biosynthesis affects the morphophysiological traits of potted ornamental Capsicum baccatum and Capsicum ...annuum growing under shade house conditions. Plants maintained in 2.7 L pots were arranged in a completely randomized design in a 2x4 factorial consisting of two pepper cultivars Chapéu-de-frade (C. baccatum) and Vulcão (C. annuum) and four paclobutrazol (PBZ) concentrations (0, 25, 50, and 75 mg L-1) with four replicates. At 30, 45, and 60 days after treatment, the plants were analyzed, and data were submitted to the analysis of general and regression variance. Gibberellin biosynthesis inhibition affected the morphophysiological and biochemical evaluations. For most evaluated traits, no interaction between factors was observed, suggesting that both pepper cultivars had a similar response to the growth regulator. PBZ-induced inhibition of gibberellin biosynthesis improved plant water status, which enhanced the vigor of potted pepper plants. The dramatic reduction of upper leaves promoted by plant growth regulators compared to basal ones negatively impacted the visual ornamental aspect of Chapéu-de-frade peppers.
RESUMO O objetivo deste estudo foi avaliar se a inibição da biossíntese de giberelinas afeta as características morfofisiológicas das espécies Capsicum baccatum e Capsicum annuum destinadas ao uso ornamental, cultivadas em vasos em casa de vegetação. As plantas foram conduzidas em vaso de 2,7 L em casa de vegetação, organizadas em delineamento inteiramente casualizado, com esquema fatorial 2x4 constituído por duas variedades de pimenteiras “Chapéu-de-frade” (C. baccatum) e “Vulcão” (C. annuum) e 4 concentrações de paclobutrazol (PBZ) (0; 25; 50 e 75 mg L-1) e quatro repetições. Aos 30, 45 e 60 dias após a aplicação do inibidor foram realizadas avaliações. A restrição da biossíntese de giberelinas promove alterações morfológicas que elevam a longevidade e vigor de folhas, e induz um status hídrico que favorece o vigor das pimenteiras envasadas. Para a cv. Chapéu-de-frade, a drástica redução do limbo foliar na parte superior resultante da ação do regulador vegetal em relação a base da copa, resultou em uma copa com menor atributo ornamental.
ABSTRACT Sweet corn (Zea mays subsp. saccharata) is mainly intended for industrial processing. Optimizing time and costs during plant breeding is fundamental. An alternative is the use of ...high-throughput phenotyping (HTP) indirect associated with agronomic traits and chlorophyll contents. This study aimed to (i) verify whether HTP by digital images is useful for screening sweet corn genotypes and (ii) investigate the correlations between the traits evaluated by conventional methods and those obtained from images. Ten traits were evaluated in seven S3 populations of sweet corn and in two commercial hybrids, three traits by classical phenotyping and the others by HTP based on RGB (red, green, blue) and multispectral imaging analysis. The data were submitted to the analyses of variance and Scott-Knott test. In addition, a phenotypic correlation graph was plotted. The hybrids were more productive than the S3 populations, showing an efficient evaluation. The traits extracted using HTP and classical phenotyping showed a high degree of association. HTP was efficient in identifying sweet corn genotypes with higher and lower yield. The vegetative canopy area (VCA), normalized difference vegetation index (NDVI), and visible atmospherically resistant index (VARI) indices were strongly associated with grain yield.
RESUMO O milho doce (Zea mays subsp. saccharata) destina-se principalmente ao processamento industrial. Otimizar tempo e custos durante o melhoramento de plantas é fundamental. Uma alternativa é o uso de fenotipagem de alto rendimento (HTP) indiretamente associada a caracteres agronômicos e teores de clorofila. Este trabalho teve como objetivo (i) verificar se a HTP por imagens digitais é útil para a seleção de genótipos de milho doce e (ii) investigar as correlações entre as características avaliadas por métodos convencionais e obtidas por imagens. Dez características foram avaliadas em sete populações S3 de milho doce e em dois híbridos comerciais, três características por fenotipagem clássica e as demais por HTP baseado em análises de imagens RGB (red, green, blue) e imagem multiespectral. Os dados foram submetidos à análise de variância e teste de Scott-Knott. Em adição, foi obtido um gráfico de correlação fenotípica. Os híbridos foram mais produtivos que as populações S3, demonstrando uma avaliação eficiente. As características extraídas por HTP e pela fenotipagem clássica apresentaram alto grau de associação. A HTP foi eficiente na identificação de genótipos de milho doce com maior e menor produtividade. Os índices VCA (vegetative canopy area), NDVI (normalized difference vegetation index) e VARI (visible atmospherically resistant index) estiveram fortemente associados à produtividade de grãos.
ABSTRACT High temperatures interfere with lettuce cropping. Thermoinhibition of seed germination and early flowering cause important losses for farmers. The objectives of this work were to evaluate ...the tolerance to early flowering, to verify the genetic dissimilarity and to select lettuce cultivars tolerant to seed thermoinhibition. 18 cultivars were evaluated. The number of days until the first anthesis was verified for early flowering. Regarding seed thermoinhibition, the first and final germination counting and germination speed index were evaluated, using temperatures of 20, 25, 30 and 35ºC. The analyses were performed immediately after harvest and after six months under storage. The genetic dissimilarity was obtained using the Tocher Graph optimization and hierarchical UPGMA methods. Regression models were adjusted, and curves’ clustering was performed by testing the identity of the models. Early flowering was observed in cultivars Floresta, Colorado, Grand Rapids, and Everglades. Cultivars showed genetic variability and are dissimilar regarding tolerance to thermoinhibition. By clustering the regression equations, it was possible to select thermoinhibition tolerant cultivars.
RESUMO As altas temperaturas interferem no cultivo da alface. A termoinibição da germinação das sementes e florecimento precoce causam perdas importantes para os produtores. Os objetivos deste trabalho foram avaliar a tolerância ao florescimento precoce, verificar a dissimilaridade genética e selecionar cultivares de alface tolerantes à termoinibição de sementes. Foram avaliadas 18 cultivares. Para florecimento precoce verificou-se o número de dias para a primeira antese. Em relação à termoinibição de sementes avaliou-se a primeira e última contagem de germinação e o índice de velocidade de germinação, utilizando-se as temperaturas de 20, 25, 30 e 35ºC. As análises foram realizadas imediatamente após a colheita e após seis meses de armazenamento. O estudo da dissimilaridade genética foi realizado por meio do método de otimização de Tocher Gráfico e hierárquico UPGMA. Os modelos de regressão foram ajustados e o agrupamento das curvas foi realizado testando a identidade dos modelos. Florescimento precoce foi observado nas cultivares Floresta, Colorado, Grand Rapids e Everglades. As cultivares apresentaram variabilidade genética e são diferentes quanto à tolerância à termoinibição. Ao agrupar as equações de regressão foi possível selecionar cultivares tolerantes à termoinibição.
Tomatillo (Physalis ixocarpa Brot. ex Horm.) is widely grown in Mexico with non-certified seed.Little research has been done on seed drying and physiology. Seed drying is a fundamental process in ...production technology, and the temperature used can affect its quality. This study aimed to evaluate the effect of different drying temperatures on the physical and physiological quality of seeds of four varieties (Tecozautla 04, Diamante, Gema and Manzano Tepetlixpa) in three storage periods. Seeds of each variety were dried in an oven until reaching constant weight at different temperatures: ambient, 30, 35, 40, 45, 50, 55 and 60 °C; subsequently, they were stored under ambient laboratory conditions for 0, 2 and 4 months. The experimental unit was 5 g of seeds. The study was carried out under a completely randomized experimental design with four replications. Physiological quality was evaluated with standard germination tests, and with the vigor test the germination speed index, total seedling length and seedling dry weight were determined. Seed quality was affected by temperature. When drying from 30 to 35 °C, the seeds expressed their maximum physiological quality, and above 45 °C their quality decreased. Tecozautla 04 had the greatest vigor, whereas Diamante had the least vigor and was the most sensitive to damage during the drying process. After two months of storage, the seeds showed the best physiological quality.
Plants raised in small cell trays are often subjected to root growth restrictions. Root tips are a source of cytokinin, and insufficient biosynthesis and transport of this hormone to the aerial part ...severely impairs shoot development. Exogenous supply of cytokinin to the foliage has been shown to effectively counteract these effects in several horticultural crops, but the physiological processes involved are still unclear. The aim of this work was to study the effect of spraying the cytokinin 6-benzylaminopurine (BAP) on growth and development of plug lettuce seedlings focusing on the morpho-physiological mechanisms involved in plant response. Two experiments were conducted in a greenhouse. Lettuce (Lactuca sativa L. Crimor INTA) seedlings were grown for 35 days in 128-, 200- and 288-cells trays (17.37, 13.90 and6.18 cm3 ·cell-1 respectively), after which they were sprayed with BAP (6-benzylaminopurine) solutions (0, 5, 50 or 100 mg·L-1) either immediately before transplant, or 7 days after transplant. Seedlings were transplanted into larger (3,000 cm3) pots in which they grew for further 60 days. Decreasing plug cell volume resulted in a steep decrease in plant net assimilation rate and leaf net photosynthetic rate, but the impact on the relative growth rate was somewhat lower due to an increased leaf area ratio. BAP sprays increased plant biomass accumulation and enhanced the development of photosynthetic area, in parallel with a strong promotion of carbon assimilation, and these effects were more remarkable in plants raised in smaller plugs, and when hormone was supplied at the pre-transplant stage.
Abstract The consumption of edible flowers has increased the search for new species to improve their nutritional impact. Therefore, the aim of this study was to determine the phenolic profile and ...nutritional value of the flowers of some Dahlia x hortorum clones (C1Var - variegated, C2Gui - cherry, C3Roj - red, C4Nar - orange, C5Ama - yellow, C6Fuc - fuchsia) and C7Ros - pink). The experiment was conducted at the Department of Plant Science, Universidad Autónoma Chapingo, Mexico, under a completely randomized experimental design with three replications. Phenolic acids (gallic, caffeic and chlorogenic) and flavonoids (quercetin and hesperidin) were detected. Similar contents of gallic acid (between 1.91 and 3.19 µg·g-1) were found in C7Ros, C1Var, C5Ama and C4Nar, where C1Var also stood out for the presence of quercetin (81.46 µg·g-1). The highest incidence of caffeic acid and hesperidin was found in C2Gui and C6Fuc. In general, C1Var showed a high percentage of crude fiber, crude fat and protein, although the last one was similar to C7Ros and C5Ama (13.68 and 13.72 µg·g-1, respectively). Likewise, C2Gui, C4Nar and C3Roj showed variation with respect to total carbohydrates (64.09, 61.64 and 62.37 %, respectively). According to the results, dahlia ligulate flowers have a significant content of phenolic acids, flavonoids, fiber and protein, as well as a variable caloric level, so they can be considered as a functional food and be integrated into daily intake.
ABSTRACT The aim of this work was to study pre-dehydration treatments to maintain consumption quality of processed potatoes (Solanum tuberosum) over a long storage period. Tubers of the cultivars ...Asterix, Macaca and Agata were cut into cubes and submitted to the following pre-dehydration treatments: water (control), blanching, and blanching with different doses of sodium metabisulfite. Sulphur dioxide residue and microorganism detection were determined right after the dehydration process was completed. Water activity, color, rehydration ratio, cooking time and rehydration ratio after cooking were determined at the beginning and after one and two years of storage. Blanching, cultivar and storage affected rehydration ratio, an important parameter used to measure the quality of dehydrated products. Tubers with higher dry mass content resulted in lower water activity and rehydration ratio, longer cooking time and higher rehydration ratio after cooking than those with lower dry mass. The combination of blanching with sodium metabisulfite improves product quality, reduces microbial load, enhances dehydration rate and prevents oxidation and browning reactions during processing and storage. The effects of the structural damages of pre-dehydration and dehydration treatments on the rehydration ratio and the rehydration ratio after cooking increase with storage of processed potatoes.
RESUMO O objetivo deste trabalho foi estudar tratamentos antes da desidratação para manter a qualidade de consumo da batata (Solanum tuberosum) processada durante um longo período de armazenamento. Tubérculos das cultivares Asterix, Macaca e Agata foram cortados em cubos e submetidos aos tratamentos antes da desidratação: água (controle), branqueamento e branqueamento com diferentes doses de metabissulfito de sódio. O resíduo de dióxido de enxofre e a detecção de microrganismos foram determinados logo após a conclusão do processo de desidratação. A atividade de água, a cor, a razão de reidratação, o tempo de cozimento e a razão de reidratação após o cozimento foram determinados no início e após um e dois anos de armazenamento. Branqueamento, cultivar e armazenamento afetaram a razão de reidratação, que é um importante parâmetro da qualidade de produtos desidratados. Tubérculos com maior teor de massa seca resultaram em menor atividade de água e razão de reidratação, maior tempo de cocção e maior taxa de reidratação após o cozimento do que aqueles com menor massa seca. A combinação de branqueamento com metabissulfito de sódio melhora a qualidade do produto, reduz a carga microbiana, aumenta a taxa de desidratação e evita reações de oxidação e escurecimento durante o processamento e armazenamento. Os efeitos dos danos estruturais causados pelos tratamentos antes e durante a desidratação sobre a razão de reidratação e a razão de reidratação após o cozimento aumentam com o tempo de armazenamento da batata processada.
The objective was to propagate select Physalis ixocarpa plants in vitro, acclimatize them and describe their phenological cycle. The in vitro response of stem apices was evaluated in families from ...the Tecozautla 04, Manzano Tepetlixpa and Morado San Miguel varieties. The apices were cultured in a medium containing Murashige and Skoog inorganic salts (100 %), supplemented with 0.4 mg·L-1 thiamine, 60 mg·L-1 L-cysteine, 100 mg·L-1 myo-inositol, 0.5 mg·L-1 nicotinic acid, 0.5 mg·L-1 pantothenic acid, 3 % sucrose and 7 g·L-1 agar, without growth regulators and the pH adjusted to 5.7 ± 0.1. in vitro rooting was done for 30 days, with 16 h of light at 3,000 μmol∙m-2∙s-1. The variables evaluated in vitro were seedling height, vigor, callus presence, root length, and number of leaves, roots, stems and buds. Plants produced in vitro were acclimatized and transplanted in greenhouses to follow their phenological cycle. The variables evaluated in acclimatization and phenological cycle were plant height and number of leaves, buds, flowers and set fruits. A completely randomized design was used for the in vitro evaluation, and randomized complete blocks for the greenhouse. The families with the best morphogenic responses in vitro were Tecozautla 04 and Manzano, and in phenological development they presented greater plant height. In acclimatization, survival was 100 % in all clones. in vitro responses, acclimatization and phenology depended on the variety and families.
Intensive tomato (Solanum lycopersicum L.) production in coastal areas of Sinaloa is exposed to significant amounts of Cl and Na deposited by sea breezes and irrigation water, which affects the yield ...of this vegetable. The aim of this study was to evaluate three percentage ratios of Cl-/anions (25/100, 50/100 and 75/100) and three percentage ratios of Na+/cations (25/100, 50/100 and 75/100) in the nutrient solution on mineral composition, dry matter production and yield of tomato. The experimental design was completely randomized with a 32 factorial arrangement and four replications. Analysis of variance and mean comparisons were performed (Tukey, P ≤ 0.05). Cl and Na concentrations in tomato leaves, stems and fruits increased significantly with increasing ratios of Cl-/anions and Na+/cations in the nutrient solution. The 75/100 Cl-/anions ratio reduced (P ≤ 0.05) the Ca concentration in leaves, while the 75/100 Na+/cations ratio decreased (P ≤ 0.05) K concentrations in leaves and stems. Both ratios reduced aerial dry biomass (48 and 25.8 %, respectively) and tomato yield (50.8 and 45.7 %, respectively). The results indicate that tomato plants grown with the 75/100 percentage ratio of Cl-/anions or the 75/100 percentage ratio of Na+/ cations absorb excessive amounts of Cl or Na, which causes ionic imbalance (especially of K+ and Ca2+) and affects dry matter production and yield.
RESUMO Devido à carência de informações sobre tecnologia de aplicação na horticultura, objetivou-se com essa pesquisa avaliar o efeito de três técnicas de aplicação em diferentes partes do dossel do ...tomateiro cultivado em ambiente protegido. As técnicas avaliadas foram 1= Lança manual com duas pontas de jato cone vazio, JA-2 (700 kPa), taxa de aplicação de 618 L ha-1; 2= Barra vertical com seis pontas de jato cone vazio, ATR 0.5 (700 kPa), taxa de aplicação de 493 L ha-1; 3= Barra vertical com seis pontas de jato plano simples, AXI 11002 (400 kPa), taxa de aplicação de 1442 L ha-1. Como indicadores de qualidade da aplicação, foram mensurados o depósito relativo (quantitativo) e a cobertura (qualitativa) das folhas do tomateiro nas posições de coleta interna e externa das plantas, nos estratos superior, médio e inferior do dossel do tomateiro. Nos estratos inferior e médio do dossel, o depósito relativo foi respectivamente 21% e 34% menor na parte interna das plantas em relação à externa, porém no estrato superior não houve diferença. Em média a cobertura foi 2,5 vezes menor na superfície abaxial em relação a adaxial. A técnica de aplicação Lança manual (618 L ha-1), utilizada na lavoura comercial, proporcionou melhor qualidade da aplicação. No entanto, há necessidade de otimização das técnicas de aplicação no intuito de proporcionar melhor distribuição da pulverização, principalmente nas regiões críticas, como a parte interna das plantas nos estratos inferior e médio do dossel e a superfície abaxial das folhas.
ABSTRACT Due to the deficiency of information on application technology in horticulture, the aim of this research was to evaluate the effect of three application techniques on different parts of the tomato canopy cultivated under greenhouse. The techniques evaluated were 1= Spray gun with two hollow cone nozzles, model JA-2 (700 kPa), application rate of 618 L ha-1; 2= Vertical boom spray equipped with six nozzles, model ATR 0.5 (700 kPa), application rate of 493 L ha-1; 3= Vertical boom spray with six standard flat fan nozzles, model AXI 11002 (400 kPa), application rate of 1442 L ha-1. As application quality indicators, the relative deposit (quantitative) and the coverage (qualitative) of the tomato leaves in the internal and external collection positions of the plants, in the upper, middle and lower strata of the tomato canopy were measured. In the lower and middle canopy strata, the relative deposit was respectively 21% and 34% smaller in the internal part of the plants in relation to the external, however in the upper stratum there was no difference. On average, the coverage was 2.5 times smaller on the abaxial surface in relation to the adaxial leaf surface. The Spray gun JA-2 (618 L ha-1), used in commercial farming, provided better quality of the application. However, there is a need to optimize the application techniques in order to provide better distribution of the spray, mainly in the critical regions, such on the inside of the plants in the lower and middle canopy strata and the abaxial surface of the leaves.
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