Artículos de revista DPA - NES Aldizkari artikuluak

Permanent URI for this collection

http://hdl.handle.net/2454/10480

Browse

Now showing 1 - 20 of 146

Open Access
Complete genome sequence of five Chrysodeixis chalcites nucleopolyhedrovirus genotypes from a Canary Islands isolate
(American Society for Microbiology, 2013-10-24) Bernal Rodríguez, Alexandra; Williams, Trevor; Muñoz Labiano, Delia; Caballero Murillo, Primitivo; Simón de Goñi, Oihane; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
The Chrysodeixis chalcites single nucleopolyhedrovirus (ChchSNPV) infects and kills C. chalcites larvae, an important pest of banana crops in the Canary Islands. Five genotypes present in the most prevalent and widespread isolate in the Canary Islands were sequenced, providing genetic data relevant to the genotypic and phenotypic diversity of this virus.
Open Access
Remarkably efficient production of a highly insecticidal Chrysodeixis chalcites nucleopolyhedrovirus (ChchNPV) isolate in its homologous host
(Wiley, 2018-01-03) Bernal Rodríguez, Alexandra; Simón de Goñi, Oihane; Williams, Trevor; Muñoz Labiano, Delia; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Background: a Chrysodeixis chalcites nucleopolyhedrovirus from the Canary Islands (ChchNPV-TF1) has proved to be effective for control of Chrysodeixis chalcites on banana crops. Commercialization of this virus as a bioinsecticide requires an efficient production system. Results: the sixth instar (L6) was the most suitable for virus production, producing 1.80 × 1011 occlusion bodies (OB)/larva and showed a lower prevalence of cannibalism (5.4%) than fourth (L4) or fifth (L5) instars. Inoculation of L6 at 24 h post molting produced six times more OB (5.72 × 1011 OB/larva) than recently molted L6 larvae (1.00 × 1011 OB/larva). No significant differences were recorded in mean time to death (165–175 h) or OB production per larva (3.75 × 1011 to 5.97 × 1011) or per mg larval weight (1.30 × 1011 to 2.11 × 109), in larvae inoculated with a range of inoculum concentrations (LC50–LC90). Groups of infected L6 larvae reared at a density of 150 larvae/container produced a greater total number of OBs (8.07 × 1013 OB/container) than lower densities (25, 50 and 100 OB/container), and a similar number to containers with 200 inoculated larvae (8.43 × 1013 OB/container). Conclusion: the processes described here allow efficient production of sufficient OBs to treat ∼ 40 ha of banana crops using the insects from a single container.
Open Access
Chrysodeixis chalcites, a pest of banana crops on the Canary Islands: incidence, economic losses and current control measures
(Elsevier, 2018-03-05) Fuentes Barrera, Ernesto Gabriel; Hernández Suárez, Estrella; Simón de Goñi, Oihane; Williams, Trevor; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Chrysodeixis chalcites is an emergent pest in bananas (Musa acuminata Colla) grown on the Canary Islands. Feeding damage to leaves and fruit and the control measures targeted at this pest were evaluated over a two-year period (2013–2014). The prevalence of infestations (42–100%) on the islands was similar during the two years of the study. Mean foliar damage (1.5–7.3% depending on island) and fruit damage (1.0–5.7%) detected in field surveys varied significantly across islands, plantation aspect (north- or south-facing) and season. Fruit damage was not correlated with foliar damage (P > 0.05). The weight of C. chalcites damaged bananas varied significantly (0.2–4.2% of harvested fruit) across islands, particularly in the spring. Overall, 3155 tonnes of bananas/yr are likely discarded due to C. chalcites damage, representing 1.5% of annual production or 2.68 million €/yr. The most frequently used pesticide was indoxacarb, usually applied on three occasions per crop cycle, for which the cost of control measures would average 240 €/ha per crop cycle. The direct damage that C. chalcites causes to banana fruit results in significant economic losses in addition to the direct costs of pesticide based control measures. Effective and sustainable control strategies are required against this pest.
Open Access
Selection of a nucleopolyhedrovirus isolate from Helicoverpa armigera as the basis for a biological insecticide
(Wiley, 2014-05-01) Arrizubieta Celaya, Maite; Williams, Trevor; Caballero Murillo, Primitivo; Simón de Goñi, Oihane; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
Background: the cotton bollworm, Helicoverpa armigera, is an insect that causes damage in a wide range of crops in Spain.Seven isolates of H. armigera single nucleopolyhedrovirus (HearSNPV) from the Iberian Peninsula were subjected to molecularand biological characterization and compared with a Chinese genotype (HearSNPV-G4). Results: the estimated sizes of the Iberian genomes varied between 116.2 and 132.4 kb, compared to 131.4 kb of theHearSNPV-G4 reference genome. Phylogenetic analysis based on the lef-8, lef-9 and polh genes revealed that the Iberianstrains were more closely related to one another than to other HearSNPV isolates. Occlusion body (OB) concentration-mortalityresponses (LC 50 values) did not differ signiﬁcantly among Iberian isolates when tested against a Helicoverpa armigera colonyfrom Oxford (UK). Despite being the fastest killing isolate, HearSNPV-SP1 was as productive as isolates with lower virulence,with an average yield of 3.1 × 109 OBs larva−1 . OBs of HearSNPV-SP1 and HearSNPV-G4 were similarly pathogenic against arecently established colony from southern Spain, although HearSNPV-SP1 was faster killing than HearSNPV-G4 against a rangeof instars. Conclusion: the insecticidal properties of HearSNPV-SP1 mean that this strain is likely to prove useful as the basis for abiological insecticide for control of Helicoverpa armigera in Spain.
Open Access
A native variant of Chrysodeixis chalcites nucleopolyhedrovirus: the basis for a promising bioinsecticide for control of C. chalcites in Canary Islands' banana crops
(Elsevier, 2013-08-13) Bernal Rodríguez, Alexandra; Williams, Trevor; Hernández Suárez, Estrella; Carnero, Aurelio; Caballero Murillo, Primitivo; Simón de Goñi, Oihane; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Chrysodeixis chalcites (Lepidoptera: Noctuidae) larvae cause up to 30% production loss in banana crops in the Canary Islands. Larvae of this species are susceptible to a nucleopolyhedrovirus (ChchNPV). This study aimed at evaluating the genetic diversity and bioinsecticidal activity of ChchNPV isolates collected from C. chalcites larvae in the Canary Islands. From a total 97 isolates collected in different banana greenhouses, restriction endonuclease analysis identified five genetic variants that differed slightly from ChchNPV isolates from Netherlands (ChchSNPV-NL) and Almería, Spain (ChchNPV-SP1). Physical maps revealed minimal differences at the genome level, mostly due to variation in the position/existence of restriction sites. ChchSNPV-TF1 was the most prevalent variant, representing 78% of isolates examined, and was isolated at all Canary Island sampling sites. This isolate was the most pathogenic isolate against C. chalcites second instars in terms of concentration-mortality metrics, compared to homologous variants or two heterologous viruses Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and Anagrapha falcifera multiple nucleopolyhedrovirus (AnfaMNPV). ChchSNPV-TF1 was also one of the fastest killing variants although no differences were observed in occlusion body production among the different variants in second instars. We conclude that ChchSNPV-TF1 merits further evaluation as the basis for a biological insecticide for control of C. chalcites in banana crops in the Canary Islands.
Open Access
Analysis of a naturally-occurring deletion mutant of Spodoptera frugiperda multiple nucleopolyhedrovirus reveals sf58 as a new per os infectivity factor of lepidopteran-infecting baculoviruses
(Elsevier, 2012-10-21) Simón de Goñi, Oihane; Palma Dovis, Leopoldo; Williams, Trevor; López Ferber, Miguel; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
The Nicaraguan population of Spodoptera frugiperda multiple nucleopolyhedrovirus, SfMNPV-NIC, is structured as a mixture of nine genotypes (A–I). Occlusion bodies (OBs) of SfMNPV-C, -D and -G pure genotypes are incapable of oral transmission; a phenotype which in SfMNPV-C and -D is due to the absence of pif1 and pif2 genes. The complete sequence of the SfMNPV-G genome was determined to identify possible factors involved in this phenotype. Deletions of 4860 bp (22,366–27,225) and 60 bp (119,759–119,818) were observed in SfMNPV-G genome compared with that of the predominant complete genotype SfMNPV-B (132,954 bp). However no genes homologous to previously described per os infectivity factors were located within the deleted sequences. Significant differences were detected in the nucleotide sequence in sf58 gene (unknown function) that produced changes in the amino acid sequence and the predicted secondary structure of the corresponding protein. This gene is conserved only in lepidopteran baculoviruses (alpha- and betabaculoviruses). To determine the role of sf58 in peroral infectivity a deletion mutant was constructed using bacmid technology. OBs of the deletion mutant (Sf58null) were not orally infectious for S. frugiperda larvae, whereas Sf58null rescue virus OBs recovered oral infectivity. Sf58null DNA and occlusion derived virions (ODVs) were as infective as SfMNPV bacmid DNA and ODVs in intrahemocelically infected larvae or cell culture, indicating that defects in ODV or OB morphogenesis were not involved in the loss of peroral infectivity. Addition of optical brightener or the presence of the orally infectious SfMNPV-B OBs in mixtures with SfMNPV-G OBs did not recover Sf58null OB infectivity. According to these results sf58 is a new per os infectivity factor present only in lepidopteran baculoviruses.
Open Access
Occlusion body pathogenicity, virulence and productivity traits vary with transmission strategy in a nucleopolyhedrovirus
(Elservier, 2011-10-25) Cabodevilla de Andrés, Oihana; Ibáñez Elosua, Itxaso; Simón de Goñi, Oihane; Murillo Pérez, Rosa; Caballero Murillo, Primitivo; Williams, Trevor; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
The prevalence of sublethal infections of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) was quantified in natural populations of S. exigua in Almería, Spain, during 2006 and 2007. Of 1045 adults collected, 167 (16.1%) proved positive for viral polyhedrin gene transcripts by RT-PCR. The prevalence of covert infection varied significantly according to sex and sample date. Of 1660 progeny of field-collected insects, lethal disease was observed in 10¿33% of offspring of transcript-positive females and 9¿49% of offspring of transcript-negative females. Isolates associated with vertically transmitted infections were characterized by restriction endonuclease analysis using BglII or EcoRV and compared with isolates originating from greenhouse soil-substrate believed to be horizontally transmitted. Insects from a sublethally infected Almerian colony were between 2.3-fold and 4.6-fold more susceptible to infection than healthy insects from a Swiss colony, depending on isolate. Horizontally transmitted isolates were significantly more pathogenic than vertically transmitted isolates in insects from both colonies. Mean speed of kill in second instars (Swiss colony) varied between isolates by >20 h, whereas mean occlusion body (OB) production in fourth instars (Swiss colony) varied by 3.8-fold among isolates. Intriguingly, all three horizontally transmitted isolates were very similar in speed of kill and OB production, whereas all three vertically transmitted isolates differed significantly from one another in both variables, and also differed significantly from the group of horizontally transmitted isolates in speed of kill (one isolate) or both variables (two isolates). We conclude that key pathogenicity and virulence traits of SeMNPV isolates vary according to their principal transmission strategy.
Open Access
Spodoptera frugiperda multiple nucleopolyhedrovirus as a potential biological insecticide: genetic and phenotypic comparison of field isolates from Colombia
(Elsevier, 2011-04-24) Barrera Cubillos, Gloria Patricia; Simón de Goñi, Oihane; Villamizar, Laura; Williams, Trevor; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Thirty-eight isolates of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), collected from infected larvae on pastures, maize, and sorghum plants in three different geographical regions of Colombia, were subjected to molecular characterization and were compared with a previously characterized Nicaraguan isolate (SfNIC). Restriction endonuclease analysis (REN) using six different enzymes showed two different patterns among Colombian isolates, one profile was particularly frequent (92%) and was named SfCOL. The physical map of SfCOL was constructed and the genome was estimated to be 133.9 kb, with few differences in terms of number and position of restriction sites between the genomes of SfNIC and SfCOL. The PstI-K and PstI-M fragments were characteristic of SfCOL. These fragments were sequenced to reveal the presence of seven complete and two partial ORFs. This region was collinear with SfMNPV sf20–sf27. However, two ORFs (4 and 5) had no homologies with SfMNPV ORFs, but were homologous with Spodoptera exigua MNPV (se21 and se22/se23) and Spodoptera litura NPV (splt20 and splt21). Biological characterization was performed against two different colonies of S. frugiperda, one originating from Colombia and one from Mexico. Occlusion bodies (OBs) of the SfCOL isolate were as potent (in terms of concentration–mortality metrics) as SfNIC OBs towards the Mexican insect colony. However, SfCOL OBs were 12 times more potent for the Colombian colony than SfNIC OBs and three times more potent for the Colombian colony than for the Mexican colony. SfCOL and SfNIC showed a slower speed of kill (by ∼50 h) in insects from the Colombian colony compared to the Mexican colony, which was correlated with a higher production of OBs/larvae. SfCOL is a new strain of SfMNPV that presents pathogenic characteristics that favor its development as the basis for a biopesticide product in Colombia.
Open Access
Population genetic structure determine the virulence and transmissibility of Spodoptera frugiperda multiple necleopolyhedrovirus
(Elsevier, 2007-12-28) Simón de Goñi, Oihane; Williams, Trevor; López Ferber, Miguel; Taulemesse, Jean-Marie; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
A Nicaraguan isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfNIC) survives as a complex mixture of genotypes (named A to I). The speed of kill, time-mortality distribution, and occlusion body (OB) production of single genotypes (A, B and F) and co-occluded mixtures of genotypes, in a 75% + 25% ratio, were compared to determine the contribution of each genotype to the transmissibility of the viral population. Pure genotypes differed markedly in their speed of kill in second instar S. frugiperda. The speed of kill of SfNIC was attenuated compared to that of the dominant genotype B, indicating that interactions involving two or more genotypes likely determine host killing traits in the virus population. Genotypes A, F and defective genotype C, had no significant effects on the distribution of insect deaths over time when present as minority components in mixtures comprising 75% of genotype B. Similarly, the mortality pattern over time of insects infected by genotype F, the fastest-killing genotype tested, was not affected by the presence of genotypes A or C. Semi-quantitative PCR studies indicated that the genetic composition did not differ significantly between SfNIC-infected insects that died soon (67 h) or late (139 h) after inoculation, suggesting that stability in genotypic composition is important for virus survival. Median OB production per insect was correlated with mean time to death so that attenuated speed of kill of SfNIC resulted in high OB yields. We conclude that (i) minority genotypes play a functional role in determining the timing of mortality of infected hosts and (ii) the genotypic structure of the virus population is stably maintained to maximize the likelihood of survival.
Open Access
Effect of optical brighteners on the insecticidal activity of a nucleopolyhedrovirus in three instars of Spodoptera frugiperda
(Blackwell Science, 2003-10-17) Martínez Castillo, Ana Mabel; Simón de Goñi, Oihane; Williams, Trevor; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena
Certain optical brighteners are effective UV protectants, and can improve the insecticidal activity of baculoviruses. We evaluated the effect of 10 optical brighteners, from four chemically different groups, on the insecticidal activity of a nucleopolyhedrovirus (SfMNPV) in third instar Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). The most effective optical brighteners were Blankophor BBH and Calcofluor M2R, both of which are stilbenes. The distyryl-biphenyl derivative, Tinopal CBS, had no effect, whereas the stilbenes, Blankophor CLE and Leucophor SAC and the styryl-benzenic derivative, Blankophor ER, resulted in a decrease in virus induced mortality compared to larvae infected with SfMNPV alone. Mixtures of SfMNPV + 0.1% Calcofluor M2R had relative potencies of 2.7, 6.5, and 61.6 in the second, third, and fourth instars, respectively. The mean time to death differed with instar, but was not affected by the addition of 0.1% Calcofluor M2R. Analysis of published studies indicated that the concentration of Calcofluor M2R-related stilbenes was positively correlated with the relative potency observed in mixtures with homologous NPVs. The average magnitude of optical brightener activity did not differ significantly between early instars of 10 species of Lepidoptera. We conclude that virus formulations containing optical brighteners may be valuable for control of late instar lepidopteran pests.
Open Access
Physical and partial genetic map of Spodoptera frugiperda nucleopolyhedrovirus (SfMNPV) genome
(Springer, 2005) Simón de Goñi, Oihane; Chevenet, François; Williams, Trevor; Caballero Murillo, Primitivo; López Ferber, Miguel; Producción Agraria; Nekazaritza Ekoizpena
A Nicaraguan isolate of Spodoptera frugiperda multicapsid nucleopolyhedrovirus (SfMNPV) is undergoing field trials for control of this pest in the Americas. This isolate is composed of multiple genotypes, some of which are deletion mutants. Identification of the genetic changes in deleted genotypes cannot be accomplished without the construction of a detailed physical map. In the present study, combinations of restriction endonuclease analysis and Southern blot analysis was performed. This map was refined by sequencing the termini of cloned restriction fragments. The SfMNPV genome was estimated to be 129.3 kb, 8 kb larger than the previously characterized Sf-2 variant from the United States, due to a deletion between 14.8 and 21.0 m.u. in the physical map described in this study. A total of 27.92 kb were sequenced, which represented 21.5% of the whole genome and included 38 ORFs. Comparison with other sequenced baculoviruses revealed that SfMNPV displayed the highest sequence identity (66%) and gene arrangement (78%) with Spodoptera exigua MNPV, sharing 36 putative ORFs. In addition, the genome organization was similar to that of SeMNPV, with minor differences. Phylogenetic analysis confirmed the close relatedness between SeMNPV and SfMNPV, suggesting they evolved from a common ancestor.
Open Access
Nucleotide sequence and transcriptional analysis of the pif gene of Spodoptera frugiperda nucleopolyhedrovirus (SfMNPV)
(Elsevier, 2005) Simón de Goñi, Oihane; Gutiérrez, Serafín; Williams, Trevor; Caballero Murillo, Primitivo; López Ferber, Miguel; Producción Agraria; Nekazaritza Ekoizpena
Defective viruses, not transmissible alone, increase the transmissibility of complete genotypes in natural populations of Spodoptera frugiperda multicapsid nucleopolyhedrovirus (SfMNPV). The defective phenotype is associated with a 15 kb deletion, which includes the pif (per os infectivity factor) gene. The sequence of a 2.4 kb fragment that includes pif was determined. Multiple transcripts encompassing pif were detected by Northern blot analysis. RT-PCR and nuclease protection analysis demonstrated the presence of run-through transcripts starting upstream of pif. A 2.0 kb messenger started from a CTAAG promoter motif located 11 nt upstream of the pif start codon, and ended 450 nt downstream from the pif stop codon. This pif mRNA included a small downstream ORF (homologous to Se37). A transcript of 0.8 kb was detected that may correspond to a specific transcript from this small ORF. This transcript would start at a late consensus motif internal to pif coding sequences, ending at the same polyadenylation signal as the pif transcript. These transcription features resemble those of pif transcription in Spodoptera littoralis NPV, although the genomic location of pif is not equivalent in the two viruses. SfMNPV pif can encode a protein of 529 amino acids, closely related to Spodoptera exigua MNPV PIF.
Open Access
Virus entry or the primary infection cycle are not the principal determinants of host specificity of Spodoptera spp. nucleopolyhedroviruses
(Microbiology Society, 2004-10-01) Simón de Goñi, Oihane; Williams, Trevor; López Ferber, Miguel; Caballero Murillo, Primitivo; Producción Agraria; Nekazaritza Ekoizpena
The multicapsid nucleopolyhedroviruses (NPVs) of Spodoptera exigua (SeMNPV), Spodoptera frugiperda (SfMNPV), and Spodoptera littoralis (SpliNPV) are genetically similar (78% similarity) but differ in their degree of host specificity. Infection by each of the three NPVs in these three Spodoptera host species was determined by oral inoculation of larvae with occlusion bodies (OBs) or intrahaemocoelic injection with occlusion derived virions (ODVs). RT-PCR analysis of total RNA from inoculated insects, targeted at immediate early (ie-0), early (egt, DNA polymerase), late (chitinase) and very late genes (polyhedrin), indicated that each of the NPVs initiated an infection in all three host species tested. SpliMNPV produced a fatal NPV disease in both heterologous hosts, S. frugiperda and S. exigua, by oral inoculation or injection. SfMNPV was lethal to heterologous hosts, S. exigua and S. littoralis, but infected larvae did not melt and disintegrate, and progeny OBs were not observed. SeMNPV was able to replicate in heterologous hosts and all genes required for replication were present in the genome, as the virus primary infection cycle was observed. However, gene expression was significantly lower in heterologous hosts. SeMNPV pathogenesis in S. frugiperda and S. littoralis was blocked at the haemocoel transmission stage and very nearly cleared. SeMNPV mixtures with SpliMNPV or SfMNPV did not extend the host range of SeMNPV; in all cases, only the homologous virus was observed to proliferate. It is concluded that entry and the primary virus infection cycle are not the only, or the major determinants, for SeMNPV infection of heterologous Spodoptera species.
Open Access
Foliar application of urea to "Sauvignon Blanc" and "Merlot" vines: doses and time of application
(Springer Nature, 2012-02-19) Lasa Larrea, Berta; Menéndez Villanueva, Sergio; Sagastizabal, Kepa; Calleja Cervantes, María Eréndira; Irigoyen Iriarte, Ignacio; Muro Erreguerena, Julio; Aparicio Tejo, Pedro María; Ariz Arnedo, Idoia; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Producción Agraria; Nekazaritza Ekoizpena
A careful control of the N nutritional status of grapevines can have a determining effect on wine characteristics; therefore a suitable management of N fertilization might allow some wine parameters to be modified, thereby improving product quality. The aim of this study was to determine the effect of foliar application of urea at different doses and different times of the growing season on the parameters of Sauvignon Blanc and Merlot grape juice. The research described herein involved Sauvignon Blanc and Merlot grapevines (V. vinifera L.) at a commercial vineyard and was conducted over 2 years. In the first year, N treatment involved a foliar application at a dose of 10 kg N ha−1 during veraison, whereas in the second year it involved a foliar urea application at two doses (10 and 50 kg N ha−1) and at three different times—3 weeks before veraison, during veraison and 3 weeks after veraison. In this second year, the urea applied at a dose of 10 kg N ha−1 was isotopically labelled with 1% 15N. Chemical parameters, yeast assimilable N, amino acid content, amino acid profile and N isotopic composition were determined for all treatments. Grape and grape-juice parameters for Merlot were found to be more affected by N fertilization than for Sauvignon Blanc and were also more affected during the second year than during the first year, thus indicating that the climatic characteristics of each campaign could affect these parameters. The yeast assimilable N in grape juice was found to be higher for late applications of foliar urea, with application of the higher dose of urea during veraison increasing the amino acid and proline contents in both varieties. The isotopic analysis data showed that the urea applied to leaves was transferred to the berries, with the maximum translocation in Sauvignon Blanc occurring for the post-veraison treatment and in Merlot for the veraison treatment. We can therefore conclude that foliar application of urea could modify grape juice quality and could therefore be used as a tool for obtaining quality wines.
Open Access
Short term physiological implications of NBPT application on the N metabolism of Pisum sativum and Spinacea oleracea
(Elsevier, 2011-03-01) Cruchaga Moso, Saioa; Artola Rezola, Ekhiñe; Lasa Larrea, Berta; Ariz Arnedo, Idoia; Irigoyen Iriarte, Ignacio; Morán Juez, José Fernando; Aparicio Tejo, Pedro María; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Producción Agraria; Nekazaritza Ekoizpena
The application of urease inhibitors in conjunction with urea fertilizers as a means of reducing N loss due to ammonia volatilization requires an in-depth study of the physiological effects of these inhibitors on plants. The aim of this study was to determine how the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) affects N metabolism in pea and spinach. Plants were cultivated in pure hydroponic culture with urea as the sole N source. After 2 weeks of growth for pea, and 3 weeks for spinach, half of the plants received NBPT in their nutrient solution. Urease activity, urea and ammonium content, free amino acid composition and soluble protein were determined in leaves and roots at days 0, 1, 2, 4, 7 and 9, and the NBPT content in these tissues was determined 48 h after inhibitor application. The results suggest that the effects of NBPT on spinach and pea urease activity differ, with pea being most affected by this treatment, and that the NBPT absorbed by the plant caused a clear inhibition of the urease activity in pea leaf and roots. The high urea concentration observed in leaves was associated with the development of necrotic leaf margins, and was further evidence of NBPT inhibition in these plants. A decrease in the ammonium content in roots, where N assimilation mainly takes place, was also observed. Consequently, total amino acid contents were drastically reduced upon NBPT treatment, indicating a strong alteration of the N metabolism. Furthermore, the amino acid profile showed that amidic amino acids were major components of the reduced pool of amino acids. In contrast, NBPT was absorbed to a much lesser degree by spinach plants than pea plants (35% less) and did not produce a clear inhibition of urease activity in this species.
Open Access
Effect of N-(n-butyl) thiophosphoric triamide on urea metabolism and the assimilation of ammonium by Triticum aestivum L.
(Springer, 2010-08-25) Artola Rezola, Ekhiñe; Cruchaga Moso, Saioa; Ariz Arnedo, Idoia; Morán Juez, José Fernando; Garnica, María; Houdusse, Fabrice; García Mina, José M.; Irigoyen Iriarte, Ignacio; Lasa Larrea, Berta; Aparicio Tejo, Pedro María; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Producción Agraria; Nekazaritza Ekoizpena
The use of urea as an N fertilizer has increased to such an extent that it is now the most widely used fertilizer in the world. However, N losses as a result of ammonia volatilization lead to a decrease in its efficiency, therefore different methods have been developed over the years to reduce these losses. One of the most recent involves the use of urea combined with urease inhibitors, such as N-(n-butyl) thiophosphoric triamide (NBPT), in an attempt to delay the hydrolysis of urea in the soil. The aim of this study is to perform an in-depth analysis of the effects that NBPT use has on plant growth and N metabolism. Wheat plants were cultivated in a greenhouse experiment lasting four weeks and fertilized with urea and NBPT at different concentrations (0, 0.012, 0.062, 0.125%). Each treatment was replicated six times. A non-fertilized control was also cultivated. Several parameters related with N metabolism were analysed at harvest. NBPT use was found to have visible effects, such as a transitory yellowing of the leaf tips, at the end of the first week of treatment. At a metabolic level, plants treated with the inhibitor were found to have more urea in their tissues and a lower amino acid content, lower glutamine synthetase activity, and lower urease and glutamine synthetase content at the end of the study period, whereas their urease activity seemed to have recovered by this stage.
Open Access
Calidad de la canal y de la carne caballar de raza Burguete
(Asociación Interprofesional para el Desarrollo Agrario, 2001) Sarriés Martínez, María Victoria; Larrea Reta, Izaskun; Induráin Báñez, Gregorio; Goñi Turumbay, Virginia; Eguinoa Ancho, Paola; Gorraiz, C.; Martín, M.; Alzueta Aldunate, María Jesús; Beriain Apesteguía, María José; Pérez de Muniáin, A.; Producción Agraria; Nekazaritza Ekoizpena
La raza caballar Burguete es una raza autóctona de Navarra que en el pasado disfrutó de gran prestigio como animal de trabajo en la Comunidad Foral y zonas limítrofes. Hoy en día por su clara aptitud cárnica es importante mantener dicho patrimonio genético y mejorar los productos obtenidos para la promoción de esta raza estableciendo criterios de tipificación (Pérez de Muniáin et al, 2000). Se trata de un producto poco conocido en el mercado de la carne, aunque en la actualidad está despertando interés debido a sus reconocidas cualidades nutritivas (producto natural y sano) como consecuencia del bajo contenido en grasa. El objetivo del presente trabajo ha sido la caracterización de la canal y de la carne caballar de raza Burguete.
Open Access
Evolución del toro de lidia: el toro actual
(Sociedad cultural Peña Pregón, 2020) Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
Trabajo en el que se hace un recorrido por la evolución del toro de lidia desde su aparción, hace tres o cuatro siglos, hasta llegar al toro moderno. El autor trata también como ha evolucionado la tauromaquia
Open Access
The influence of the accessory genome on bacterial pathogen evolution
(Taylor & Francis, 2011) Jackson, Robert W.; Vinatzer, Boris; Arnold, Dawn L.; Dorus, Steve; Murillo Martínez, Jesús; Producción Agraria; Nekazaritza Ekoizpena
Bacterial pathogens exhibit significant variation in their genomic content of virulence factors. This reflects the abundance of strategies pathogens evolved to infect host organisms by suppressing host immunity. Molecular arms-races have been a strong driving force for the evolution of pathogenicity, with pathogens often encoding overlapping or redundant functions, such as type III protein secretion effectors and hosts encoding ever more sophisticated immune systems. The pathogens’ frequent exposure to other microbes, either in their host or in the environment, provides opportunities for the acquisition or interchange of mobile genetic elements. These DNA elements accessorize the core genome and can play major roles in shaping genome structure and altering the complement of virulence factors. Here, we review the different mobile genetic elements focusing on the more recent discoveries and highlighting their role in shaping bacterial pathogen evolution.
Open Access
Mipob: un programa de simulación para el aprendizaje en mejora genética animal
(Universidad de Córdoba, 2014) Alfonso Ruiz, Leopoldo; Producción Agraria; Nekazaritza Ekoizpena
Se ha desarrollado un programa de simulación de apoyo a la docencia de los cursos introductorios a la Mejora genética animal. El programa surgió ante la ausencia de este tipo de herramientas docentes orientadas a estudiantes de primeros cursos de grado universitario, especialmente en lengua española. El programa simula una población animal cerrada de censo reducido en la que los estudiantes deben de ir tomando las decisiones de elección de futuros reproductores y cómo aparearlos. De esta forma se facilita la introducción de los conceptos básicos sobre selección y evaluación genética, y conservación y genética de poblaciones. El programa considera el caso particular del vacuno de carne y se pueden realizar hasta un total de diez generaciones de selección. Tras haber sido probado durante dos cursos consecutivos en enseñanza reglada universitaria, está disponible de forma gratuita para su libre utilización y distribución.