ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Estudio de la diversidad del hongo responsable de la piriculariosis del arroz, y su aplicación
Get PDFMagnaporthe oryzae es responsable de la enfermedad mas importante del arroz en
Europa. En este trabajo se recogieron 987 aislados de este hongo en siete países europeos
productores de arroz, y se investigó su diversidad genética con 11 marcadores microsatélite.
Los genotipos multilocus (MLGs) más frecuentes son comunes a los países europeos. Sin
embargo, algunos son específicos de los distintos países, o incluso de determinadas áreas de
cultivo. La diversidad genotípica media en los campos de cultivo revela que, a pesar de que
hay uno o dos genotipos dominantes, frecuentemente coexisten varios genotipos. La hipótesis
del arroz rojo como una fuente de inóculo primario no se puede excluir. La evolución
genética de M.oryzae se ha investigado en dos de estos países en los últimos 25 años: en
Francia se han observado cambios significativos de la población con el tiempo, al contrario
que en ltalia. Estos datos muestran que hay un importante flujo de genes entre las zonas
arroceras europeas, probablemente a través del transporte de semillas infectadas. También
muestran evidencias de diferenciación en una escala geográfica muy pequeña, lo que sugiere
una adaptación local
Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit
No full textThe antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternate. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 degrees C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 degrees C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternate more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot. (C) 2013 Elsevier B.V. All rights reserved
Citrus (Rutaceae) SNP markers based on Competitive Allele-Specific PCR; transferability across the Aurantioideae subfamily.
Get PDFUNLABELLED: ; PREMISE OF THE STUDY: Single nucleotide polymorphism (SNP) markers based on Competitive Allele-Specific PCR (KASPar) were developed from sequences of three Citrus species. Their transferability was tested in 63 Citrus genotypes and 19 relative genera of the subfamily Aurantioideae to estimate the potential of SNP markers, selected from a limited intrageneric discovery panel, for ongoing broader diversity analysis at the intra- and intergeneric levels and systematic germplasm bank characterization. ; METHODS AND RESULTS: Forty-two SNP markers were developed using KASPar technology. Forty-one were successfully genotyped in all of the Citrus germplasm, where intra- and interspecific polymorphisms were observed. The transferability and diversity decreased with increasing taxonomic distance. ; CONCLUSIONS: SNP markers based on the KASPar method developed from sequence data of a limited intrageneric discovery panel provide a valuable molecular resource for genetic diversity analysis of germplasm within a genus and should be useful for germplasm fingerprinting at a much broader diversity level
Alternatives to ginger root oil aromatherapy for improved mating performance of sterile Ceratitis capitata (Diptera: Tephritidae) males
No full textAutocidal control of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) is an environmentally friendly and safe practice employed successfully worldwide. A key component in the Sterile Insect Technique (SIT) is to release sterile males that can compete with wild males in nature. Exposure of sterile males to ginger root oil (GRO) in the form of aromatherapy prior to release has been shown to significantly improve male competitiveness and performance. However, alternatives to GRO exposure are desired to (i) reduce personnel costs and handling-time requirements and (ii) find new aromatherapeutic compounds. In this study, alternatives to GRO aromatherapy were investigated, such as incorporating GRO into the post-teneral diet, or employing other molecules (limonene and linalool) occurring naturally in citrus release areas. Our results reveal that both the GRO-supplemented diet and linalool aromatherapy were equal to the GRO aromatherapy control in improving mating performance in sterile males. In contrast, exposure to limonene did not afford a mating advantage to sterile mates when compared to the control. In addition, sterile male survival was not affected by any of the treatments tested. Implications for how both new approaches could be implemented in SIT programmes in citrus production areas are discussed
Molecular analysis of the genomic RNAs 1 and 2 of the first Arabis mosaic virus isolate detected in Spanish grapevines. Short communication.
No full textThe Arabis mosaic virus (ArMV) is one of the causative agent of the grapevine fanleaf disease, one of the most widespread and damaging viral diseases of grapevine. Recently, the ArMV has been detected in Spanish vineyards, and its determination and molecular characterization was undertaken. To this aim, the nucleotide sequence of the genomic RNAs 1 and 2 of the first isolate of ArMV infecting grapevine detected in Spain (ArMV-DU13) has been determined. The ArMV-DU13 genomic sequences were compared to the corresponding sequences of other isolates of ArMV, or nepoviruses. The most divergent genes among ArMV isolates were the X1 and VPg genes on the RNA 1, and the 2A gene on the RNA 2, with identity levels at the amino acid level of 78% (X1 and VPg) or 69% (2A) between the most distant isolates. Interestingly, the VPg genes were identical between the two grapevine isolates ArMV-Du13 and -NW, suggesting a possible implication of the host. The phylogenetic analysis of the RNA 2 showed that the Spanish isolate was close to Grapevine fanleaf virus isolates. The analysis of the full length RNA 2 suggests a recombination event between ArMV-DU13 and GFLV-GHu isolates between nucleotides 54 and 586 in the ArMV-DU13 isolate. Altogether, these results confirm the high variability between isolates of ArMV, and will be helpful to design more appropriate and reliable molecular diagnostic techniques for the control of this emerging virus in Spain
Strategy I responses to Fe-deficiency of two Citrus rootstocks differing in their tolerance to iron chlorosis
No full textThe expression of iron (Fe) acquisition-related genes in roots was studied in roots of two different citrus seedlings, namely, Carrizo citrange (CC, Fe chlorosis-sensitive) and Cleopatra mandarin (CM, Fe chlorosis-tolerant), growing either with (control) or without (-Fe) Fe in the nutrient solution. Fe-deficiency increased expression of the gene HA] coding for proton-ATPase (H+-ATPase) enzyme in both genotypes, although no differences were observed between treatments among rootstocks. Furthermore, while the gene expression levels of FRO2 - which encodes the Ferric Chelate Reductase (FC-R) enzyme-, increased under -Fe condition in both genotypes, CM always recorded the highest activity. CC showed the greatest induction of genes IRT1 and IRT2 encoding two iron transporters, however only IRT1 was significantly induced by Fe starvation. Analysis of the enzymatic activities (H+-ATPase and FC-R) regulated by the aforementioned genes confirmed these results. Thus, in agreement with the acidification pattern registered, H+-ATPase activities were higher in -Fe plants than in controls, although no significant differences were detected between each treatment among rootstocks. Fe starvation also induced FC-R activity; however, this was greater in CM than in CC roots. Interestingly, root Fe-57 uptake rates from Fe-57-EDDHA solutions were increased by Fe-deficiency, especially in the CM genotype, and CM accumulated a much larger Fe pool in the root apoplast than CC. Taken together, the main trait determining Fe-chlorosis tolerance among these genotypes is the ability to boost Fe3+ reduction in response to Fe-deficiency through enhanced FRO2 gene expression. Moreover, Fe chlorosis resistance in these plants could be related to the amount of Fe stored in the root apoplast. (C) 2013 Elsevier B.V. All rights reserved
Proteomic study of 'Moncada' mandarin buds from on- versus off-crop trees
No full textA proteomic analysis of buds from mandarin trees with contrasting fruit load (on- and off-crop trees) was carried out during the onset of low-temperature induction. The aim of the study was to find out more about the molecular mechanism relating to alternate bearing in Citrus and its relationship with flowering. The ‘Moncada’ variety (Clementine ‘Oroval’ x ‘Kara’ mandarin), displaying remarkable behaviour in alternate production, was used in this study. From 2D DIGE gel, 192 spots were isolated: 97 showed increased expression in the off-crop buds as compared to the on-crop buds, while 95 exhibited enhanced expression in the on-crop buds versus the off-crop buds. These spots were identified by MALDI-MS or LC–MS–MS. The largest groups of proteins up-expressed in the off-crop buds were the proteins involved in carbohydrate and amino acid metabolism, and the proteins expressed in response to stimuli such as reactive oxygen species. The largest groups of proteins up-expressed in the on-crop buds were related to primary metabolism, oxidative stress and defence responses. Depending on their function, some of these proteins can stimulate the flowering, such as fructose-bisphosphate aldolase or leucine-rich repeat transmembrane protein kinase, while others can inhibit it, such as cytochrome c oxidase subunit II. Twenty-two other proteins with unknown functions were up-expressed in the on- or off-crop buds
Technical Note: Effect of Handling on Stress-Induced Hyperthermia in Adult Rabbits
No full textAnimals perceive humans as a threat, therefore handling could cause stress reactions and fear in rabbits. Stress induced hyperthermia (SIN) is a physiological response produced when a stressful situation takes place and is supposed to occur in rabbits. In this work, the SIH response is assessed when different groups of rabbits (young males, nulliparous does and multiparous does) are handled. A benzodiazepine (Midazolam (R)) was administered to half of the animals to assess handling response also under drug effects. Rectal temperature was not increased by handling in male rabbits and multiparous does, whereas nulliparous females showed presented SIH after 30 min of handling. In addition, Midazolam (R) has been revealed as useful for pharmacological validation of SIH after 25 min from injection
Prediction of components of the sporopollenin synthesis pathway in peach by genomic and expression analyses
Get PDFBackground: The outer cell wall of the pollen grain (exine) is an extremely resistant structure containing sporopollenin, a mixed polymer made up of fatty acids and phenolic compounds. The synthesis of sporopollenin in the tapetal cells and its proper deposition on the pollen surface are essential for the development of viable pollen. The beginning of microsporogenesis and pollen maturation in perennial plants from temperate climates, such as peach, is conditioned by the duration of flower bud dormancy. In order to identify putative genes involved in these processes, we analyzed the results of previous genomic experiments studying the dormancy-dependent gene expression in different peach cultivars. Results: The expression of 50 genes induced in flower buds after the endodormancy period (flower-bud late genes) was compared in ten cultivars of peach with different dormancy behaviour. We found two co-expression clusters enriched in putative orthologs of sporopollenin synthesis and deposition factors in Arabidopsis. Flower-bud late genes were transiently expressed in anthers coincidently with microsporogenesis and pollen maturation processes. We postulated the participation of some flower-bud late genes in the sporopollenin synthesis pathway and the transcriptional regulation of late anther development in peach. Conclusions: Peach and the model plant Arabidopsis thaliana show multiple elements in common within the essential sporopollenin synthesis pathway and gene expression regulatory mechanisms affecting anther development. The transcriptomic analysis of dormancy-released flower buds proved to be an efficient procedure for the identification of anther and pollen development genes in perennial plants showing seasonal dormancy