ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Acta Horticulturae
No full textIn the Mediterranean area, the production of persimmon (Diospyros kaki Thunb.) [2n=6x=90] has increased recently as an alternative to the major fruit crops. In Spain, production relies almost exclusively on the ‘Rojo Brillante’ which accounts for 83% of the crop. Monovarietal culture implies several commercial and phytosanitary problems that can compromise the future of the crop. Main persimmon breeding objectives are focused on obtaining new cultivars with the positive agronomic features of ‘Rojo Brillante’ but with more diversity in ripening date, astringency and fruit characteristics. In order to increase the genetic variability available for breeding, the strategy of mutagenesis with γ-radiation was employed. Shoot buds of the persimmon ‘Rojo Brillante’ were subjected to various doses of gamma rays, 15 and 20 Gy from a Co-60 source (treatment A) and 20 and 25 Gy with a linear accelerator (treatment B). The genetic variability induced was analyzed in 420 plants using four AFLP primer combinations. Irradiated buds were grafted in the field and bud sprout rate appreciably decreased with the increase of the dose. The most favorable gamma irradiation dose combining survival and mutation induction was 20 Gy. AFLP data analyses revealed high genetic variability produced by 20 Gy: treatment A resulted in 29.8% of polymorphic loci (PPL) and treatment B resulted in 45.8% of PPL
Short Communication: Assessment of Activity Patterns of Growing Rabbits in a Flux-Controlled Chamber
Get PDFFlux-controlled and metabolic chambers are often used for nutritional and environmental studies. However, the potential alterations of animal behaviour and welfare are so far not fully understood. In consequence, this study had 2 main objectives: to assess potential alterations of animal activity pattern and time budget inside a flux chamber, and to assess the importance of the “rearing up” behaviour. To this end, 10 growing rabbits of different ages (from 1 to 5 wk of the growing period) were housed inside a flux chamber. Their activity was continuously recorded and assessed, determining the frequency and duration of 8 different behaviours: lying, sleeping, sitting, eating, drinking, walking, rearing up and others. Nocturnal rabbit behaviour and time budget were not altered inside the chamber if compared to previously described rabbit activity under conventional cages. In addition, rabbits in this experiment presented a tendency to perform “rearing up” when housed inside the flux chamber
Development of a pododermatitis score in breeding does using clustering methods
No full textPododermatitis in rabbit production is an important welfare problem and there is less information on this type of lesion in rabbits than in many other species. The aim of this work was to develop a scoring system to assess the presence and severity of pododermatitis through observation of 1367 photos of rabbit feet by two observers. Different groups of lesions were established according to color, size, presence of chaps, presence of ulcers, shape, appearance and presence of blood in each observed foot. A two-step cluster methodology was used to gather the results in homogenous and objective units. The inter-rater agreement was moderate, and after the cluster analysis four main clusters were obtained. These clusters were later comprehensively described in terms of pododermatitis severity. Finally, attending to cluster description, a five-level score was defined and this scale resulted in a practical and objective way to assess pododermatitis in rabbit does. Cluster analysis provided a detailed characterization of this type of lesions and helped to obtain uniform scores
Towards Cisgenics to Improve Citrus Health and Nutritional Quality Through Metabolic Engineering
No full textTranscriptome analysis in Ceratitis capitata to unveil genes involved in ageing-maturation process
Get PDFThe sterile insect technique (SIT) is widely used in integrated programmes against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Information on the age distribution of insects, and more particularly, the knowledge of wild female reproductive status (mature or not) at the time of the sterile male release is one of the key factors for the success of the SIT. In recent years, sequencing analysis has become an important tool in molecular biology. In this work we present a genome-wide expression analysis based on SSH (substractive sequence hybridization) and EST (expressed sequence tag) sequencing and macroarray expression analysis to identify signature genes related to the ageing-maturing process in C. capitata, leading to the successful identification of new putative candidate genes of reproductive status in medfly that would serve as molecular markers for ageing. We have sorted out 94 unigenes from 873 single-pass ESTs, of which 57% have homology with known genes. Ageing-maturing process in C. capitata presents a marked expression pattern accompanied by the increase of transcription level of genes involved in reproduction (vitellogenins, chorion proteins and male-specific serum proteins). Other identified cDNAs (43%) with a differential expression pattern would be also candidates but deserve further studies, as they belong to the unknown function class
Postharvest application of a new growth regulator reduces calyx alterations of citrus fruit induced by degreening treatment
No full textSynthetic auxins, specially 2,4-dichlorophenoxyacetic acid (2,4-D), have been used as a postharvest treatment to retard calyx abscission, drying and browning, which occur as the result of degreening processes. Nevertheless, the use of 2,4-D is restricted by European Union (EU) legislation, which means that finding an alternative to this auxin in controlling calyx senescence is necessary. In the present research, the effect of postharvest application of a new growth regulator, S-ethyl-4-chloro-O-tolilooxytioacetate (HF-Calibra (R)), currently registered for preharvest use, was used to investigate calyx senescence of early-season citrus varieties ('Oronules', 'Clemenrubi' and 'Clemenules' mandarins and 'Navelina' oranges) submitted to a commercial degreening treatment. After shelf-life, application of HF-Calibra (R) treatment at different concentrations significantly reduced calyx changes. Although auxin treatments can retard color change, this delay had no negative effect from a commercial viewpoint since all the studied varieties reached a commercially acceptable color. The application of HF-Calibra (R) at 10, 20, 40 or 60 mL/L affected neither weight loss nor sensory quality of the fruit (firmness, total soluble solids, titratable acidity, acetaldehyde and ethanol content and flavor). Postharvest application of HF-Calibra (R) could be an alternative to 2.4-D to avoid calyx senescence of citrus fruit induced by a degreening treatment and to maintain fruit quality. (c) 2012 Elsevier B.V. All rights reserved
Usefulness of thermography for plant water stress detection in citrus and persimmon trees
Get PDFThe feasibility of using canopy temperature (T-c) measured with a hand-operated infrared thermographic camera as a water stress indicator was evaluated in the field during two seasons on citrus and persimmon trees subjected to different levels of deficit irrigation. In both species, which differ in leaf anatomy and stomatal response to environmental conditions, T-c, was compared with midday stem water potential (Psi(s)) measurements. In persimmon trees, leaf stomatal conductance (g(s)) was also measured. In 2009, images were taken from the sunlit and shady sides of the canopies. Based on the results obtained, during the second experimental season images were taken from the sunlit side of the trees and also from above the canopy. In persimmon, trees under deficit irrigation had lower Psi(s) and g(s) what resulted in a clear increase in T-c regardless of the position from where the pictures were taken. The maximum T-c difference between deficit-irrigated and control trees observed was of 4.4 degrees C, which occurred when the stressed trees had Psi(s) values 1.1 MPa lower than the control ones. In persimmon trees, T-c was the most sensitive indicator of plant water status particularly due to the lower tree-to-tree variability as compared to Psi(s) and g(s). On the other hand, in citrus trees T-c was not always affected by plant water stress. Only in the second experimental season, when air vapour pressure deficit values were below 2.7 kPa and images were also taken from above the canopies, deficit-irrigated trees had higher T-c than the control ones, this difference being at most 1.7 degrees C. Overall, the results show that hand-operated thermographic cameras can be used to detect plant water stress in both fruit tree species. Nevertheless, the use of T-c measurements to detect plant water stress appears to be more precise in persimmon than in orange citrus. This might be because persimmon trees have larger leaf size which determines higher canopy resistance allowing for higher increases in canopy temperature in response to water stress via stomatal closure. (C) 2012 Elsevier B.V. All rights reserved
Fortuitous biological control of the invasive mealybug Phenacoccus peruvianus in Southern Europe
No full textPhenacoccus peruvianus Granara de Willink (Hemiptera: Pseudococcidae) is a Neotropical invasive mealybug that has rapidly spread throughout Mediterranean Basin. It has established itself as the principal pest of several ornamental plants, causing considerable problems in nurseries and urban landscapes. The aim of this study was to determine the natural enemy complex of this pest and report the feasibility of its biological control. Six urban green spaces were surveyed in eastern Spain from 2008 to 2010. The most abundant natural enemies of P. peruvianus were found to be the primary parasitoids Acerophagus n. sp. near coccois and Leptomastix epona Walker (Hymenoptera: Encyrtidae). Phenacoccus peruvianus populations were lower during the second and third year of the survey, coinciding with an increase of the parasitoid Acerophagus sp., which displaced the native L. epona. Differential female offspring and resource preemption are discussed as the main reasons for this displacement
Morphological characterization of the IVIA persimmon (Diospyros kaki Thunb.) germplasm collection by multivariate analysis
No full textDiospyros kaki Thunb. originated in Eastern Asia, as evidenced of its culture in China as early as several centuries B.C. In the seventh century, persimmon was introduced to Japan and later, in the fourteenth century to Korea. There is no information about persimmon culture in Europe until the seventeenth century, with the spread over the world occurring in the eighteenth century. The genus Diospyros contains more than 400 species, with levels of ploidy ranging from diploid (2n = 2x = 30) up to nonaploid (2n = 9x = 135). The primary economic crop species is Diospyros kaki Thunb., which is mainly hexaploid (2n = 6x = 90) and includes hundreds of cultivars. Although a relatively recent introduction in Europe, the species has adapted well, and the genetic diversity have been expanded with culture and selection for the past 200 years in the Mediterranean basin. These locally adapted cultivars were evaluated with cultivars from Asian origin in a germplasm collection established at IVIA in Valencia, Spain. In this paper 27 cultivars from the IVIA collection were studied by multivariate analysis, and 37 variables were analyzed using a Principal Components Analysis and cluster analysis following the method UPGMA. Studies on correlations and significance among variables identified the most relevant ones, and thus provided information for a future core collection