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The preimaginal stages and development of Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) on Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)
No full textThe development and morphology of the immature phases of Spalangia cameroni Perkins, 1910 (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 smooth and the micropyle occurs at the anterior end. The immature larvae are similar to the mature larva, differing mainly in the size of the head capsule and mandibles. The mature larva displays tubercules on the body segments as well as a pleurostoma and superior and inferior mandibular processes. On completion of its larval development, an adecticous and exarate pupa is produced. The mandibles of the pupa, as for the adult, are toothed. Three larval instars are recorded based on statistical analyses of the sizes of the larval mandibles and head capsules, in combination with such characters as the number of exuviae and excretion of the meconium. There are significant positive correlations between mandible length and width of larval head capsule with the number of instars, thus indicating that the mandible length and width of larval capsule are good predictors of the number of instars in this parasitoid. Developmental time from egg to adult emergence was similar to 33-34 days for females and similar to 28-29 days for males at 21-26 degrees C, 55-85 RH and a L16:D8 photoperiod. Our results show that the eggs and different instars of S. cameroni can be unambiguously identified only by SEM. Therefore, characterization of the immature stages of Spalangia species using SEM should be done before subsequent routine identifications using a binocular microscope or stereomicroscope
Effect of Oxytocin Treatment on Artificial Insemination with Frozen-Thawed Semen in Murciano-Granadina Goats
No full textThe site where the semen is deposited appears to be one of the most important factors affecting pregnancy of inseminated goats. In Murciano-Granadina (MG) goats, post-cervical insemination is achieved in a limited number of females. An effective way to increase fertility rate could be by increasing post-cervical inseminations. Effect of exogenous oxytocin application to facilitate the cervical penetration and its effect on kidding rate and prolificacy in MG goats were investigated. Oestrus was synchronized using progesterone-impregnated sponges for 11 days. Females were randomly divided into three groups (n = 190) and received either an i.v. injection of 100 or 200 IU of oxytocin or saline solution 15 min before being inseminated. Data on semen deposition depth were recorded for each animal using a catheter scaled in centimetres (up to 4 cm). Depth of semen deposition was affected by the oxytocin treatment (p < 0.05). Oxytocin enhanced cervical passage only with the dose of 200 IU compared with the control group, increasing the deposition depth (2.9 cm vs 1.9 cm). No significant effect of oxytocin treatment on kidding rate and prolificacy was detected. Depth of semen deposition affected kidding rate (p < 0.01). In conclusion, oxytocin treatment improved the depth of semen deposition in AI of MG goats, but kidding rate and prolificacy was not affected. More studies must be conducted to assess the minimal effective dose required for sufficient cervical dilation, and to determine the effects of such doses of oxytocin on uterine motility, sperm transport and fertility in goats
Recognition and classification of external skin damage in citrus fruits using multispectral data and morphological features
No full textThe computer vision systems currently used for the automatic inspection of citrus fruits are normally based on supervised methods that are capable of detecting defects on the surface of the fruit but are unable to discriminate between different types of defects. identifying the type of the defect affecting each fruit is very important in order to optimise the marketing profit and to be able to take measures to prevent such defects from occurring in the future. In this paper, we present a computer vision system that was developed for the recognition and classification of the most common external defects in citrus. in order to discriminate between 11 types of defects, images of the defects were acquired in five spectral areas, including the study of near infrared reflectance and ultraviolet induced fluorescence. The system combines spectral information about the defects with morphological estimations of them in order to classify the fruits in categories. The fruit-sorting algorithm proposed here was tested by using it to identify the defects in more than 2000 citrus fruits, including mandarins and oranges. The overall success rate reached 86%
A spontaneous mutant of 'L-202' rice. Short Communication.
No full textA new spontaneous phenotype of the rice cultivar 'L-202' was found. Mendelian analysis indicates that it is a monogenic, recessive mutant. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tittering and relatively short height. The objectives of this study were: to characterize it, to determine if it is heritable and if so, its genetic basis. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tittering and relatively short height. Selfing the new phenotype resulted in a uniform progeny, with the traits of the parent plant ("wild type"). Crossing the new phenotype with the normal 'L-202' cultivar resulted in a uniform F(1) hybrid generation, with the wild type. The F(2) generation showed a mendelian seggregation which did not depart significantly from three normal plants : one new phenotype. It is concluded that it is a monogenic, recessive mutant
Effects of post-teneral nutrition and ginger root oil exposure on longevity and mortality in bait treatments of sterile male Ceratitis capitata
Get PDFArea-wide Sterile Insect Technique (SIT) programmes against medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), are being increasingly implemented worldwide. A key issue for SIT is to release sterile males that are sufficiently competitive with males from the wild population. Post-teneral nutrition and ginger root oil (GRO) exposure of sterile males prior to release have been shown to improve male competitiveness or performance. However, few studies are available on the effect of post-teneral nutrition and ginger oil exposure on longevity and mortality in bait treatments by sterile male C. capitata. In this study, we found that longevity was increased by the addition of protein to the standard pre-release sugar diet, whereas exposure to GRO did not influence the longevity of sterile males. Mortality in spinosad baits was influenced both by diet and GRO exposure. Sterile males on a protein-deprived diet suffered greater mortality than sterile males fed with both sugar and protein. When sterile males were fed on the protein-deprived diet, GRO exposure increased their mortality. However, no significant differences were found in adults on the sugar-protein diet, whether or not they had been exposed to GRO. These results show, for the first time, a negative effect of GRO exposure in terms of increasing mortality in proteinaceous bait treatments, a common practice in areas where SIT is implemented. Nevertheless, this effect could be reduced by the addition of protein to the standard pre-release diet. The implications of these results for SIT programmes against C. capitata are discussed. © 2009 The Netherlands Entomological Society
Survival of Erwinia amylovora in mature apple fruit calyces through the viable but nonculturable (VBNC) state
No full textAims: Survival of Erwinia amylovora, causal agent of fire blight in pome fruits and other rosaceous plants, was monitored inside mature apples calyces under some storage conditions utilized in fruit.
Methods and Results: Apple fruit calyces inoculated with two E. amylovora strains and their respective GFP-marked strains were maintained at 26° and 5°C, and the effect of copper treatment was assayed at 0·01 and 0·1 mmol l−1 CuSO4. In nontreated apples at 26°C, part of the population of E. amylovora survived in the ‘viable but nonculturable’ (VBNC) state, whereas at 5°C the majority of the population retained culturability. In copper-treated apples, the whole population adopted the VBNC state irrespective of temperature. Regardless of temperature, copper and inoculum dose, VBNC cells recovered culturability and pathogenicity in King’s B broth or by host plant passage.
Conclusions: Erwinia amylovora survived for at least 35 days in mature apple calyces. Besides, the ability of the pathogen in the VBNC state to regain culturability and pathogenicity suggests that the apple fruit could be a potential carrier of E. amylovora contributing to the spreading of fire blight disease.
Significance and Impact of the Study: The risk of E. amylovora dissemination through mature fruit transport, although low, has been demonstrated, and should be considered in pest risk assessments
Pcr Detection and Identification of Plant-Pathogenic Bacteria: Updated Review of Protocols (1989-2007)
No full textPCR-based methods offer advantages over more traditional diagnostic tests, in that organisms do not need to be cultured prior to their detection and protocols are highly sensitive and rapid. Consequently, there is a shift in research towards DNA-based techniques. Although reports already exist on a variety of PCR-based fingerprinting assays used to analyse the genetic diversity of bacterial populations and define their relationships, this review focuses on the general use of PCR in phytobacteriology for detection and diagnosis purposes. An updated and detailed list of published PCR protocols for detection and identification of plant-pathogenic bacteria is presented and discussed, aimed at facilitating access to information that could be particularly useful for diagnostic laboratories. This compilation includes and discusses 246 articles published between 1989 and 2007 addressing 23 genera, more than 50 species, 10 subspecies and more than 40 pathovars
Acta Horticulturae
No full textMost of the Spanish commercial acreage of persimmon is located in the Southeast area of the country. Our goal was to identify fungi causing postharvest diseases in our local environmental conditions. Persimmons cvs. ‘Rojo Brillante’ and ‘Triumph’ from two different orchards were used during two consecutive seasons to assess both latent pathogens (field infections) and wound pathogens (postharvest infections). Healthy persimmons were either surface-disinfected with 0.5% sodium hypochlorite or artificially wounded in the rind and placed in humid chambers at 20°C for up to 7 weeks. Additionally, decay was periodically assessed on commercially-handled fruit stored at 1°C for 4 months. Isolated fungi were plated in potato dextrose agar (PDA) Petri dishes and incubated at 25°C for further macroscopic and/or microscopic identification. Although identification of few pathogens causing minor decay is pending, results indicated that the main causal agents of latent and wound infections were Alternaria alternata and Penicillium spp. The same pathogens and also Botrytis cinerea and Cladosporium spp. were the fungi most frequently isolated from cold-stored fruit
Exposure of Fresh Sperm to Cholesterol-loaded Cyclodextrins Improves In vitro Fertilizing Ability of Frozen-thawed Boar Sperm
No full textEffect of antifungal hydroxypropyl methylcellulose (HPMC)-lipid edible composite coatings on postharvest decay development and quality attributes of cold-stored 'Valencia' oranges
No full textEdible composite coatings based on hydroxypropyl methylcellulose (HPMC), hydrophobic components (beeswax and shellac), and food preservatives with antifungal properties were evaluated on 'Valencia' oranges during long-term cold storage. Selected food preservatives included potassium sorbate (PS), sodium benzoate (SB), sodium propionate (SP), and their mixtures. Intact oranges or oranges artificially inoculated with Penicillium digitatum or Penicillium italicum were coated and stored up to 60 d at 5 degrees C followed by 7d of shelf-life at 20 degrees C. Some antifungal HPMC-lipid coatings significantly reduced incidence and severity of both green (GM) and blue (BM) molds on inoculated and cold-stored oranges, and PS+SP-based coating was the most effective. In general, the coatings controlled GM better than BM. After 30 and 60 d at 5 degrees C plus 7 d at 20 degrees C, fruit weight loss, rind firmness, internal gas concentrations, ethanol and acetaldehyde contents of the juice, sensory flavor, off-flavor, and fruit appearance were not adversely affected by application of the antifungal coatings, which showed promise as potential substitutes for citrus commercial waxes. However, further studies should follow to improve some coating physical characteristics in order to provide better water loss control and higher gloss on coated oranges. (C) 2009 Elsevier B.V. All rights reserved