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Acalá del Río, Spain

Aguado A.,Centro IFAPA Las Torres Tomejil | De Los Santos B.,Centro IFAPA Las Torres Tomejil | Gamane D.,University of Seville | Garcia del Moral L.F.,University of Granada | Romero F.,Centro IFAPA Las Torres Tomejil
Field Crops Research

Verticillium wilt (VW), caused by Verticillium dahliae Kleb., has become one of the most serious problems in cotton (Gossypium hirsutum L.). The use of resistant cultivars has long been considered the most practical and effective means of control. The objective of this work was to study the quantitative genetic basis of fiber traits under Verticillium conditions in upland cotton by using five genotypes and their possible crosses without reciprocals, selecting simultaneously for quality fiber, resistance, and agronomic characteristics. Five cotton cultivars and 10 F1s from half diallel crosses were analyzed for quality fiber under VW conditions. The fiber length, uniformity, strength, elongation, and micronaire were measured during two crop seasons at two different sites each year, consistently in plots with soil naturally infested with Verticillium. Genetic components of variance were analyzed using the Hayman model. Analysis of variance for all traits showed significant differences between genotypes, with the genotype-site interaction in most of the studied traits except for fiber length and micronaire. Both the additive genetic variance component (D) and dominance genetic variance components (H1 and H2) were present in all traits. D was the most important component for uniformity, strength, elongation, and micronaire. Elongation was the trait most correlated with seed-cotton yield. Strength and micronaire were the traits most correlated with VWI. Broad-sense heritability was high for all the traits studied. Narrow-sense heritability was high for uniformity, strength and elongation, and moderate for length and micronaire. 'Acala Prema' and 'Acala Germain-510' were identified as the best parent cultivars to breed for uniformity and strength. 'Acala Prema', 'Acala Germain-510', and 'Deltapine Acala 90' were the best to improve elongation and micronaire characters. © 2009 Elsevier B.V. All rights reserved. Source

Lima R.S.N.,University of Evora | Lima R.S.N.,Federal University of Sergipe | Garcia-Tejero I.,Centro IFAPA Las Torres Tomejil | Lopes T.S.,State University of Norte Fluminense | And 6 more authors.
Agricultural Water Management

Water deficit is the most limiting factor for yield and fruit-quality parameters in papaya crop (Carica papaya L.), deficit-irrigation (DI) strategies offering a feasible alternative to manage limiting water resources. When DI is applied, it is crucial to assess the physiological status of the crop in order to maintain the plant within a threshold value of water stress so as no to affect yield or fruit-quality parameters. The aim of this work was to evaluate the feasibility of thermal imaging in young papaya plants to assess the physiological status of this crop when it is subjected to different DI regimes, studying the relationships between the changes in leaf temperature (Tleaf) and in the major physiological parameters (i.e., stomatal conductance to water vapor, gs; transpiration, E; and net photosynthesis, An). The trial was conducted in a greenhouse from March to April of 2012. Plants were grown in pots and subjected to four irrigation treatments: (1) a full irrigation treatment (control), maintained at field capacity; (2) a partial root-zone drying treatment, irrigated with 50% of the total water applied to control to only one side of roots, alternating the sides every 7 days; (3) a regulated deficit irrigation (50% of the control, applied to both sides of plant); (4) and a non-irrigated treatment, in which irrigation was withheld from both sides of the split root for 14 days, followed by full irrigation until the end of the study. Significant relationships were found between Tleaf and major physiological variables such as gs, E and An. Additionally, significant relationships were found between the difference of leaf-to-air temperature (ΔTleaf-air) and gas-exchange measurements, which were used to establish the optimum range of ΔTleaf-air as a preliminary step to the crop-water monitoring and irrigation scheduling in papaya, using thermal imaging as the main source of information. According to the results, we conclude that thermal imaging is a promising technique to monitor the physiological status of papaya during drought conditions. © 2015 Elsevier B.V. Source

Aguado A.,Centro IFAPA Las Torres Tomejil | Pastrana A.M.,Centro IFAPA Las Torres Tomejil | De Los Santos B.,Centro IFAPA Las Torres Tomejil | Romero F.,Centro IFAPA Las Torres Tomejil | And 2 more authors.
Acta Horticulturae

Strawberry anthracnose, caused by Colletotrichum acutatum J.H. Simmonds, has been reported from most areas of the world where strawberries are grown. The use of chemical phytosanitary products to control fungal diseases has been drastically reduced by EU legislation. For that reason, the development of nonchemical alternatives respectful with the environment and human health is urgent. This study tries to evaluate the effect of two natural products which previously showed a potential as plant defense inductors and in vitro biofungicide activity in the control of C. acutatum. Strawberry plants grown under temperature and humidity controlled conditions were treated with a biofungicide product containing seaweed (Ascophyllum nodosum) and cinnamon (Cinnamomum sp.) extracts (0.5%); a plant defense inductor based on quitosan (0.25%); a chemical fungicide (0.3% Chlorthalonil) as positive control, and water as negative control. 24 h after application of these products, plants were inoculated with a conidial suspension of C. acutatum. Non-treated and non-inoculated plants were used as control of natural occurring infection. The progress of C. acutatum infection was monitored by quantifying the amount of fungi at 24 h, 72 h, 7 days and 15 days after inoculation. A reliable, sensitive and fast TaqMan real-time PCR using dilutions of plant crude extracts, without the need of DNA extraction, was used to detect and quantify C. acutatum in the treated and then inoculated plants. Results demonstrated the efficiency of the assayed natural products in controlling the development of the fungus in the plant up to 15 days after treatment. This real-time PCR method based in the use of plant crude extract allows a rapid and sensitive detection and quantification of low amounts of fungus in the plant, even before the appearance of symptoms. Source

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