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Automatic sex detection of individuals of Ceratitis capitata by means of computer vision in a biofactory
No full textBACKGROUND: The sterile insect technique (SIT) is acknowledged around the world as an effective method for biological pest control of Ceratitis capitata (Wiedemann). Sterile insects are produced in biofactories where one key issue is the selection of the progenitors that have to transmit specific genetic characteristics. Recombinant individuals must be removed as this colony is renewed. Nowadays, this task is performed manually, in a process that is extremely slow, painstaking and labour intensive, in which the sex of individuals must be identified. The paper explores the possibility of using vision sensors and pattern recognition algorithms for automated detection of recombinants. RESULTS: An automatic system is proposed and tested to inspect individual specimens of C. capitata using machine vision. It includes a backlighting system and image processing algorithms for determining the sex of live flies in five high-resolution images of each insect. The system is capable of identifying the sex of the flies by means of a program that analyses the contour of the abdomen, using fast Fourier transform features, to detect the presence of the ovipositor. Moreover, it can find the characteristic spatulate setae of males. Simulation tests with 1000 insects (5000 images) had 100% success in identifying male flies, with an error rate of 0.6% for female flies. CONCLUSION: This work establishes the basis for building a machine for the automatic detection and removal of recombinant individuals in the selection of progenitors for biofactories, which would have huge benefits for SIT around the globe. (C) 2008 Society of Chemical Industr
Direct sample preparation methods for the detection of Plum pox virus by real-time RT-PCR
Get PDFDirect systems to process plant materials allowed high-throughput testing of Plum pox virus (PPV) by real-time reverse transcription (RT)-PCR without nucleic acids purification. Crude plant extracts were diluted in buffer or spotted on membranes to be used as templates. Alternatively, immobilized PPV targets were amplified from fresh sections of plant tissues printed or squashed onto the same supports, without extract preparation. Spot real-time RT-PCR was validated as a PPV diagnostic method in samples collected during the dormancy period and showed high sensitivity (93.6%), specificity (98.0%), and post-test probability (97.9%) towards sharka disease. In an analysis of 2919 Prunus samples by spot real-time RT-PCR and DASI-ELISA 90.8% of the results coincided, demonstrating high agreement (k = 0.77 +/- 0.01) between the two techniques. These results validate the use of immobilized PPV targets and spot real-time RT-PCR as screening method for large-scale analyses. [Int Microbiol 2009; 12(1): 1-6
Survey of natural enemies of spider mites (Acari: Tetranychidae) in citrus orchards in eastern Spain
Get PDFField surveys were conducted from 2004 to 2007 to determine the species composition and relative abundance of natural enemies associated with colonies of either the citrus red mite, Panonychus citri, or the two spotted spider mite, Tetranychus urticae, in Valencian citrus orchards (eastern Spain). Fourteen species were recorded, six phytoseiid mites and eight insect predators. Two of them are reported for the first time on citrus in Spain and two more are first reports as predators associated with T. urticae. The community of predators associated with T. urticae and P. citri was almost identical, and the Morisita-Horn index of similarity between both natural enemy complexes was close to one, suggesting that predators forage on both pest species. Quantifying the presence of many known spider mites predators in Valencian citrus orchards is an important first step towards spider mite control. A challenge for future studies will be to establish conservation and/or augmentation management strategies for these predators, especially to improve T. urticae biological control
Recovery of Nonpathogenic Mutant Bacteria from Tumors Caused by Several Agrobacterium tumefaciens Strains: a Frequent Event?
No full textWe have evaluated the interaction that bacterial genotypes and plant hosts have with the loss of pathogenicity in tumors, using seven Agrobacterium tumefaciens strains inoculated on 12 herbaceous and woody hosts. We performed a screening of the agrobacteria present inside the tumors, looking for nonpathogenic strains, and found a high variability of those strains in this niche. To verify the origin of the putative nonpathogenic mutant bacteria, we applied an efficient, reproducible, and specific randomly amplified polymorphic DNA analysis method. In contrast with previous studies, we recovered a very small percentage (0.01%) of nonpathogenic strains that can be considered true mutants. Of 5,419 agrobacterial isolates examined, 662 were nonpathogenic in tomato, although only 7 (from pepper and tomato tumors induced by two A. tumefaciens strains) could be considered to derive from the inoculated strain. Six mutants were affected in the transferred DNA (T-DNA) region; one of them contained IS426 inserted into the iaaM gene, whereas the whole T-DNA region was apparently deleted in three other mutants, and the virulence of the remaining two mutants was fully restored with the T-DNA genes as well. The plasmid profile was altered in six of the mutants, with changes in the size of the Ti plasmid or other plasmids and/or the acquisition of new plasmids. Our results also suggest that the frequent occurrence of nonpathogenic clones in the tumors is probably due to the preferential growth of nonpathogenic agrobacteria, of either endophytic or environmental origin, but different from the bacterial strain inducing the tumor
Production of tetraploid plants of non apomictic citrus genotypes
No full textPloidy manipulation in Citrus is a major issue of current breeding programs aiming to develop triploid seedless mandarins to address consumer demands for seedless fruits. The most effective method to obtain triploid hybrids is to pollinate tetraploid non apomictic cultivars with pollen of diploid varieties. Such non apomictic tetraploid lines are not found in the citrus germplasm and need to be created. In this work we describe a new methodology based on in vitro shoot-tip grafting combined with treatment of the micro-grafted shoot-tip with colchicine and oryzalin to achieve chromosome doubling and a dechimerization procedure assisted by flow cytometry. Stable tetraploid plants of Clemenules, Fina and Marisol clementines and Moncada mandarin have been obtained directly from shoot tip grafting combined with colchicine and oryzalin treatments or after dechimerization of mixoploids plants (2x-4x). These stable tetraploid plants have been used in 4x x 2x hybridizations, to recover over 3,250 triploid hybrids in 3 years
Rabbit sperm cryopreservation: A review
No full textSperm cryopreservation is a great challenge, since many sperm are irreversibly damaged or present altered functionality after the whole process. Although components of extenders for sperm cryopreservation are quite similar between species, sperm from each of the species present peculiarities that force researchers to optimize the extenders and protocols for each particular species. In this review, information related to rabbit sperm cryopreservation is compiled. The topics discussed include the extenders and protocols developed for rabbit sperm cryopreservation, as well as fertility data obtained after artificial insemination with cryopreserved sperm and factors that may have an impact on the results obtained. In addition, suggestions for improving the results after cryopreservation of rabbit sperm are also proposed
Aspectos generales de la agricultura ecológica
Get PDFLa denominación de agricultura ecológica en la Unión
Europea se refiere indistintamente a tres modalidades de agricultura
alternativa: orgánica, biológica y biodinámica. Y entre las
definiciones posibles, podemos definir la agricultura ecológica
según la propuesta por la Sociedad Española de Agricultura
Ecológica (SEAE), como “Un sistema perdurable de producción
agraria cuyo objetivo fundamental es la obtención de alimentos
de máxima calidad, respetando el medio ambiente y mejorando o
conservando la fertilidad de la tierra, mediante la utilización óptima
de los recursos locales, potenciando las culturas rurales, los
valores éticos del desarrollo rural y la calidad de vida”
Computer vision developments for the automatic inspection of fresh and processed fruits
Get PDFThe quality of a fresh or processed fruit or vegetable is defined by a series of characteristics which make it more or less attractive to the consumer, such as ripeness, size, weight, shape, colour, presence of blemishes and diseases, presence or absence of fruit stems, seeds, etc. In summary, these characteristics may cover all of the factors that exert an influence on the product’s appearance, on its nutritional and organoleptic qualities or on its suitability for preservation. Most of these factors have traditionally
been assessed by visual inspection performed by trained operators. However, the application of machine vision in agriculture has increased considerably in recent years since it provides substantial information about the nature and attributes of the produces, reduces costs, guarantees the maintenance of quality standards and provides useful information in real time. Moreover, machine vision opens the possibility of exploring agricultural products in invisible regions of the electromagnetic spectrum, as in the ultraviolet or infrared regions. Instituto Valenciano de Investigaciones Agrarias (IVIA) has developed during the past 15 years computer vision systems for the automatic, on-line inspection of fresh and processed fruits and vegetables. This paper shows the most important outcomes in this matter achieved by the department called Centro de Agroingeniería. One of such systems is a machine for the automatic inspection of pomegranate arils for fresh consumption. This machine individualizes, inspects, classifies and separates the arils in four categories, removing those that do not fulfil the minimal specifications. Multivariate analysis models are used to classify the arils with an average success about 90%. Another application is a machine to classify mandarin segments for canning. The system distinguishes among sound, broken or double segments, and is able to detect the presence of seeds in the segments. The system analyses the shape of the each individual segment to estimate morphological features that are used to classify it into different commercial categories. The machine classifies correctly more than 75% of the analyzed segments. Both systems are currently patent pending. In the field of computer vision systems for the inspection of fresh, whole fruit, most research
has been focused on citrus fruits. While most commercial systems only detect the blemishes on the skin of fruit, a multispectral system has been developed to identify them. The system is capable of identifying the 11 most common defects of citrus skin using near infrared, colour and ultraviolet. It also uses induced ultraviolet fluorescence. The success rate achieved with such system reached 87% when identifying about 800 defects in five species of oranges and mandarins. The use of hyperspectral sensors makes it possible to conduct a more sophisticated analysis of the scene by acquiring sets of images corresponding to particular wavelengths. Using this technology, we have conducted different works aimed at detecting damages in citrus fruits, including fungal infestation. The acquired multi-dimensional spectral signature characterising a pixel has been used to analyse scenes and to detect different types of defects such as decay, more easily than using standard colour imaging systems
The Preimaginal Phases and Development of Pachycrepoideus vindemmiae (Hymenoptera, Pteromalidae) on Mediterranean Fruit Fly, Ceratitis capitata (Diptera, Tephritidae)
No full textThe development and morphology of the immature phases of Pachycrepoideus vindemmiae (Rondani, 1875) (Hymenoptera, Pteromalidae) are described from a laboratory rearing culture maintained on Ceratitis capitata (Wiedemann, 1824) (Diptera, Tephritidae) using microscopic techniques, including light and scanning electron microscopy. The surface of the chorion of the egg is granulated, and the micropyle occurs at the anterior end. The labrum of the first instar larva does not have sensilla, and the second to fourth instar larvae have setae on the head. The mature larva is characterized by the position and number of the integumental differentations (sensilla and setae). On completion of larval development, an adecticous and exarate pupa is produced. As for the adult, the mandibles of the pupae are toothed. Five larval instars are recorded, based on statistical analyses of the sizes of the larval mandibles in combination with characters such as the number of exuviae and excretion of the meconium. Developmental time from egg to adult emergence was similar to 18-20 days for males and similar to 21-23 days for females at 21-26 degrees C, 55-85 relative humidity, and a 16L:8D photoperiod. The results show that the eggs and different larval instars of this parasitoid can be unambiguously identified only by scanning electron microscope
Curative and Preventive Activity of Hydroxypropyl Methylcellulose-Lipid Edible Composite Coatings Containing Antifungal Food Additives to Control Citrus Postharvest Green and Blue Molds
No full textEdible composite coatings based on hydroxypropyl methylcellulose (HPMC), lipid components (beeswax and shellac), and food preservatives with antifungal properties were evaluated in vivo on clementine mandarins cv. Clemenules, hybrid mandarins cv. Ortanique, and oranges cv. Valencia. Their curative and preventive activity against citrus postharvest green (GM) and blue molds (BM), caused by Penicillium digitatum (PD) or Penicillium italicum (PI), respectively, were determined. Fruits were artificially inoculated before or after the application of the coatings and incubated up to 7 days at 20 degrees C. Selected food preservatives included mineral salts, organic acid salts, parabens, and 2-deoxy-D-glucose. Inoculated but uncoated fruits were used as controls. For curative activity, HPMC-lipid edible composite coatings containing sodium benzoate (SB) were most effective in reducing the incidence and severity of GM on clementine mandarins cv. Clemenules (86 and 90%, respectively). On this cultivar, the reduction in GM incidence by the SB-based coating was twice that of potassium sorbate (PS)-based coating. On mandarins cv. Ortanique, PS- and SB-based coatings reduced the incidence of GM and BM by more than 40 and 21%, respectively. However, the HPMC-lipid coating containing a mixture of PS and sodium propionate (PS + SP) exhibited a synergistic effect in the reduction of the incidence of GM (78%) and BM (67%). Coatings with parabens modestly reduced disease incidence and severity. On oranges cv. Valencia, coatings with food preservatives better controlled BM than GM. Coatings containing SB + PS and SB + SP reduced the incidence and severity of BM by 85% and 95%, respectively. PS- and SB- based coatings controlled GM more effectively than coatings formulated with other food preservatives. In every cultivar, fruit coated before inoculation did not show any incidence or severity reduction of both GM and BM (preventive activity). In every test, the antifungal action of the coatings was fungistatic rather than fungicidal