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Diego Rubiales - One of the best experts on this subject based on the ideXlab platform.

  • Resistance to rusts (Uromyces pisi and U. Viciae-Fabae) in pea
    Czech Journal of Genetics and Plant Breeding, 2018
    Co-Authors: Eleonora Barilli, Josefina C. Sillero, E. Prats, Diego Rubiales
    Abstract:

    Barilli E., Sillero J.C., Prats E., Rubiales D. (2014): Resistance to rusts (Uromyces pisi and U. Viciae-Fabae) in pea. Czech J. Genet. Plant Breed., 50: 135–143. Pea is the second most important food legume crop in the world. Rust is a pea disease widely distributed, particularly in regions with warm, humid weather. Pea rust can be incited by Uromyces Viciae-Fabae and by U. pisi . U. Viciae-Fabae prevails in tropical and subtropical regions such as India and China, while U. pisi prevails in temperate regions. Chemical control of rust is possible, but the use of host plant resistance is the most desired means of rust control. In this paper we revise and discuss the occurrence and incidence of both pathogens on peas, the availability of resistance sources and the present state of the art in pea breeding against this disease.

  • Response of Vicia Species to Ascochyta fabae and Uromyces Viciae-Fabae
    Czech Journal of Genetics and Plant Breeding, 2018
    Co-Authors: Josefina C. Sillero, Diego Rubiales
    Abstract:

    Sillero J.C., Rubiales D. (2014): Response of Vicia species to Ascochyta fabae and Uromyces Viciae-Fabae . Czech J. Genet. Plant Breed., 50: 109–115. A collection of 267 accessions belonging to 61 Vicia species other than V. faba was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces Viciae-Fabae , causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp . in contrast to the high susceptibility previously reported in most V. faba accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. Viciae-Fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. Viciae-Fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.

  • Identification and multi-environment validation of resistance to rust (Uromyces Viciae-Fabae) in Vicia faba
    Crop and Pasture Science, 2017
    Co-Authors: Josefina C. Sillero, Amero A. Emeran, María M. Rojas-molina, Mohamed Kharrat, Johanna Winkler, H. R. Khan, Fernando Flores, Diego Rubiales
    Abstract:

    A germplasm collection of 484 accessions of Vicia faba was screened for resistance to rust (Uromyces Viciae-Fabae) under field conditions. Accessions varied in the levels of rust infection, although no complete resistance was identified. Stability of resistance of the 39 most-resistant accessions was tested in a multi-location experiment in Austria, Egypt, Tunisia, United Kingdom and Spain over three additional field seasons. Genotype × environment interaction accounted for 43% of the sum of squares of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. This might hamper the efficiency of selection suggesting the need for selection in different environments. Three possible mega-environments were discerned in the studied area, Mediterranean (Spain, Tunisia and Egypt), Oceanic (UK) and Continental (Austria). Cordoba (Spain) and Kafr El-Sheik (Egypt) showed as ideal environments for rust resistance screenings within Mediterranean environment. Several accessions (300, 303, 311, 313, 720, 1196 and 1271) were grouped as moderately to highly resistant in the three defined mega-environments. These accessions showed clear differences both in terms of reduced disease severity and high stability, which make them good candidates for international faba bean breeding programmes. Concerning each mega-environment, accessions 300 and 311 were the most resistant and stable ones across the Mediterranean one, followed by accessions 720, 1022, 1272, 1320 and BPL261. On the contrary other accessions (313, 452, 481 and 1196) were the most resistant in Oceanic and Continental environments. However, 452 and 481 were susceptible in the Mediterranean mega-environment. This contrasting performance across the environments was also supported by contradictory performance of the checks BPL261 and Baraca in Oceanic and Continental environments, suggesting differential virulence in rust populations, which deserves further attention.

  • Response of Vicia species to Ascochyta fabae and Uromyces Viciae-Fabae
    Czech Journal of Genetics and Plant Breeding, 2014
    Co-Authors: Josefina C. Sillero, Diego Rubiales
    Abstract:

    A collection of 267 accessions belonging to 61 Vicia species other than V. faba was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces Viciae-Fabae, causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp. in contrast to the high susceptibility previously reported in most V. faba accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. Viciae-Fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. Viciae-Fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.

  • Resistance to rusts (Uromyces pisi and U. Viciae-Fabae) in pea
    Czech Journal of Genetics and Plant Breeding, 2014
    Co-Authors: E. Barilli, Jc Sillero, E. Prats, Diego Rubiales
    Abstract:

    Pea is the second most important food legume crop in the world. Rust is a pea disease widely distributed, particularly in regions with warm, humid weather. Pea rust can be incited by Uromyces Viciae-Fabae and by U. pisi. U. Viciae-Fabae prevails in tropical and subtropical regions such as India and China, while U. pisi prevails in temperate regions. Chemical control of rust is possible, but the use of host plant resistance is the most desired means of rust control. In this paper we revise and discuss the occurrence and incidence of both pathogens on peas, the availability of resistance sources and the present state of the art in pea breeding against this disease.

Josefina C. Sillero - One of the best experts on this subject based on the ideXlab platform.

  • Response of Vicia Species to Ascochyta fabae and Uromyces Viciae-Fabae
    Czech Journal of Genetics and Plant Breeding, 2018
    Co-Authors: Josefina C. Sillero, Diego Rubiales
    Abstract:

    Sillero J.C., Rubiales D. (2014): Response of Vicia species to Ascochyta fabae and Uromyces Viciae-Fabae . Czech J. Genet. Plant Breed., 50: 109–115. A collection of 267 accessions belonging to 61 Vicia species other than V. faba was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces Viciae-Fabae , causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp . in contrast to the high susceptibility previously reported in most V. faba accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. Viciae-Fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. Viciae-Fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.

  • Resistance to rusts (Uromyces pisi and U. Viciae-Fabae) in pea
    Czech Journal of Genetics and Plant Breeding, 2018
    Co-Authors: Eleonora Barilli, Josefina C. Sillero, E. Prats, Diego Rubiales
    Abstract:

    Barilli E., Sillero J.C., Prats E., Rubiales D. (2014): Resistance to rusts (Uromyces pisi and U. Viciae-Fabae) in pea. Czech J. Genet. Plant Breed., 50: 135–143. Pea is the second most important food legume crop in the world. Rust is a pea disease widely distributed, particularly in regions with warm, humid weather. Pea rust can be incited by Uromyces Viciae-Fabae and by U. pisi . U. Viciae-Fabae prevails in tropical and subtropical regions such as India and China, while U. pisi prevails in temperate regions. Chemical control of rust is possible, but the use of host plant resistance is the most desired means of rust control. In this paper we revise and discuss the occurrence and incidence of both pathogens on peas, the availability of resistance sources and the present state of the art in pea breeding against this disease.

  • Identification and multi-environment validation of resistance to rust (Uromyces Viciae-Fabae) in Vicia faba
    Crop and Pasture Science, 2017
    Co-Authors: Josefina C. Sillero, Amero A. Emeran, María M. Rojas-molina, Mohamed Kharrat, Johanna Winkler, H. R. Khan, Fernando Flores, Diego Rubiales
    Abstract:

    A germplasm collection of 484 accessions of Vicia faba was screened for resistance to rust (Uromyces Viciae-Fabae) under field conditions. Accessions varied in the levels of rust infection, although no complete resistance was identified. Stability of resistance of the 39 most-resistant accessions was tested in a multi-location experiment in Austria, Egypt, Tunisia, United Kingdom and Spain over three additional field seasons. Genotype × environment interaction accounted for 43% of the sum of squares of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. This might hamper the efficiency of selection suggesting the need for selection in different environments. Three possible mega-environments were discerned in the studied area, Mediterranean (Spain, Tunisia and Egypt), Oceanic (UK) and Continental (Austria). Cordoba (Spain) and Kafr El-Sheik (Egypt) showed as ideal environments for rust resistance screenings within Mediterranean environment. Several accessions (300, 303, 311, 313, 720, 1196 and 1271) were grouped as moderately to highly resistant in the three defined mega-environments. These accessions showed clear differences both in terms of reduced disease severity and high stability, which make them good candidates for international faba bean breeding programmes. Concerning each mega-environment, accessions 300 and 311 were the most resistant and stable ones across the Mediterranean one, followed by accessions 720, 1022, 1272, 1320 and BPL261. On the contrary other accessions (313, 452, 481 and 1196) were the most resistant in Oceanic and Continental environments. However, 452 and 481 were susceptible in the Mediterranean mega-environment. This contrasting performance across the environments was also supported by contradictory performance of the checks BPL261 and Baraca in Oceanic and Continental environments, suggesting differential virulence in rust populations, which deserves further attention.

  • Response of Vicia species to Ascochyta fabae and Uromyces Viciae-Fabae
    Czech Journal of Genetics and Plant Breeding, 2014
    Co-Authors: Josefina C. Sillero, Diego Rubiales
    Abstract:

    A collection of 267 accessions belonging to 61 Vicia species other than V. faba was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces Viciae-Fabae, causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp. in contrast to the high susceptibility previously reported in most V. faba accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. Viciae-Fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. Viciae-Fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.

  • Identification of pre‐ and posthaustorial resistance to rust (Uromyces viciae‐fabae) in lentil (Lens culinaris) germplasm
    Plant Breeding, 2013
    Co-Authors: Diego Rubiales, María M. Rojas-molina, Josefina C. Sillero
    Abstract:

    Lentil (Lens culinaris Medik.) is an important cool-season legume that can be severely damaged by rust (Uromyces Viciae-Fabae (Pers.) Schrot.) in many parts of the world. In this work, a collection of L. culinaris germplasm accessions was screened under growth chamber conditions for response to U. Viciae-Fabae. Several sources of incomplete resistance have been identified, both of hypersensitive and of non-hypersensitive nature. Incomplete hypersensitive resistance was due to a late-acting host cell necrosis that resulted in an intermediate infection type (IT). Incomplete non-hypersensitive resistance was due to a hampered cell penetration not associated with host cell necrosis, reducing the number of haustoria per colony and therefore hindering the growth of the colony and reducing and retarding disease development in spite of a high IT.

Kurt Mendgen - One of the best experts on this subject based on the ideXlab platform.

  • Plasma Membrane H+-ATPase Activity in Spores, Germ Tubes, and Haustoria of the Rust Fungus Uromyces Viciae-Fabae
    Fungal genetics and biology : FG & B, 1996
    Co-Authors: Christine Struck, Matthias Hahn, Kurt Mendgen
    Abstract:

    Abstract Using plasma membrane-enriched vesicles, the properties of the H+-ATPase (EC 3.6.1.35) from the rust fungusUromyces Viciae-Fabaewere studied. The enzyme is strictly Mg2+-dependent and is inhibited by vanadate. The pH-optimum is at 6.7. By Western blot analysis using a monoclonal antibody against corn plasma membrane H+-ATPase a polypeptide of approximately 104 kDa could be detected. The vanadate-sensitive H+-ATPase activity of microsomal vesicles obtained from different stages of rust development was determined. Uredospores had only a very low enzyme activity (1.9 μmol Pi × mg−1protein × h−1). In germ tubes the ATPase activity was about twofold higher (4.0 μmol Pi × mg−1protein × h−1). An eightfold higher ATPase activity (16.1 μmol Pi × mg−1protein × h−1) was found in microsomal vesicles from haustoria which had been isolated from rust-infectedVicia fabaleaves. These results suggest, that the electrochemical gradient generated by the H+-ATPase of haustoria plays an important role for their function, possibly by promoting nutrient uptake from host cells.

  • regulation of pectin methylesterase and polygalacturonate lyase activity during differentiation of infection structures in Uromyces viciae fabae
    Microbiology, 1995
    Co-Authors: H B Deising, Alexander K. Frittrang, Stefan Kunz, Kurt Mendgen
    Abstract:

    the kinetics of their synthesis and the Kms of the three major isoenzymes were determined. The enzyme activity was formed independently of the presence of its substrate and its regulation was thus differentiation-specific. A single PL was induced when haustoriaI mother cells were formed and its synthesis appeared to be controlled by both the developmental stage of infection structures and the availability of its substrate. Polygalacturonate concentrations lower than 0'025 mg ml- 1 induced enzyme synthesis, and at 0'25 mg ml- 1 the induction proces's appeared to be saturated. Enzyme formation in the presence of 50 mM glucose, fructose or sucrose suggested that neither pectic enzyme was subject to catabolite repression. Significant proportions of PME (approx. 57%) and PL (approx. 76%) activity were located extracellularly in 24-h-old differentiated infection structures and could contribute to the establishment of the parasite. Physico-chemical and kinetic properties of the enzymes and associated alterations of the apoplastic pH of infected host plants appeared to be important factors in the success of infection and could explain the restriction of cell wall damage at the penetration site usually observed in interactions involving obligately biotrophic fungi.

  • Extracellular proteases of the rust fungus Uromyces Viciae-Fabae
    Experimental Mycology, 1995
    Co-Authors: Martina Rauscher, Kurt Mendgen, Holger B. Deising
    Abstract:

    Abstract Rauscher, M., Mendgen, K., and Deising, H. 1995. Extracellular proteases of the rust fungus Uromyces Viciae-Fabae. Experimental Mycology 19, 26-34. On thigmo-inductive membranes the broad bean rust fungus Uromyces Viciae-Fabae differentiates complex infection structures including haustorial mother cells. Using this in vitro system, formation of extracellular proteases of the obligately biotrophic fungus was studied during infection structure differentiation. Enzyme activities occur when appressoria are formed, and extracellular washing fluids of substomatal vesicles, infection hyphae, and haustorial mother cells show complex protease patterns on polyacrylamide gels containing gelatin as substrate. The majority of the rust proteases can be classified as metallo-, including Ca 2+ -stabilized proteases. The presence of substrate is not required for synthesis of the enzymes. The extracellular proteases, in contrast to intracellular enzymes of this fungus, specifically degrade fibrous, hydroxyproline-rich proteins. Since such proteins are important in plants for cell wall stability and play a role in defense against fungal pathogens, the extracellular proteases of U. Viciae-Fabae may be involved in localized breaching of the host cell wall.

  • Cellulolytic enzymes of the obligately biotrophic rust fungus Uromyces Viciae-Fabae are regulated differentiation-specifically
    Mycological Research, 1993
    Co-Authors: Stefan Heiler, Kurt Mendgen, Holger B. Deising
    Abstract:

    Uredospores of the obligately biotrophic broad bean rust fungus Uromyces Viciae-Fabae form infection structures on artificial membranes providing a thigmotropic signal. In nature these are essential for invasion of the host plant through the stomata. This experimental system was used to analyse the production of cellulolytic enzymes during the differentiation of rust infection structures. Low cellulase activity was detected in dormant spores and in germ tubes. Enzyme activity increased during appressorium development and reached a maximum when infection hyphae and haustorial mother cells were formed. Seven cellulolytic enzymes were separated by chromatofocusing on DEAE = Si500 and PBE 94 exchangers. At least two cellulases, characterized by isoelectric points of 7·1 and 7·3, were identified as endo -cellulases. The neutral enzyme forms increased from 3·3% of the total activity at appressorium formation to 36·6% when infection hyphae were formed (18 h p.i.), and to 45·4% in haustorial mother cells (24 h p.i.). Cellulase activity of the rust fungus is neither substrate-inducible nor catabolite repressible. The regulation of these enzymes appears to be strictly controlled by the differentiation of infection structures, and is therefore distinct from cellulases of necrotrophs and saprophytes investigated thus far.

  • Characterization and partial purification of pectinesterase, a differentiation-specific enzyme of Uromyces Viciae-Fabae
    Journal of General Microbiology, 1992
    Co-Authors: Alexander K. Frittrang, Holger B. Deising, Kurt Mendgen
    Abstract:

    The differentiation-specific formation of three isoforms of pectinesterase by the broad bean rust fungus Uromyces Viciae-Fabae is described. Activity becomes detectable when substomatal vesicles are formed. In crude extracts isoform A contributed 78% of the total pectinesterase activity, and isoforms B and C contributed 20% and 2%, respectively. All three isoforms were found extracellularly in ratios identical to those in extracts. The isoelectric points of the pectinesterase isoforms were 8.4 (A), 5.7 (B), and 4.7 (C) as determined by chromatofocusing. Isoform A had an M r of 33500 and showed a distinct pH optimum at 6.0. The M r of isoform B was 40000; its pH optimum ranged from 5.5 to 7.5. Due to its extremely low activity, isoform C was not further characterized. The possible role of pectinesterases in the infection process of the broad bean rust fungus is discussed.

Rubiales Diego - One of the best experts on this subject based on the ideXlab platform.

  • Identification and multi-environment validation of resistance to rust (Uromyces Viciae-Fabae) in Vicia faba
    'CSIRO Publishing', 2017
    Co-Authors: Sillero, Josefina C., Emeran, Amero A., Rojas-molina, María M., Kharrat Mohamed, Winkler Johana, Khan, Habib R., Flores Fernando, Rubiales Diego
    Abstract:

    A germplasm collection of 484 accessions of Vicia faba was screened for resistance to rust (Uromyces Viciae-Fabae) under field conditions. Accessions varied in the levels of rust infection, although no complete resistance was identified. Stability of resistance of the 39 most-resistant accessions was tested in a multi-location experiment in Austria, Egypt, Tunisia, United Kingdom and Spain over three additional field seasons. Genotype × environment interaction accounted for 43% of the sum of squares of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. This might hamper the efficiency of selection suggesting the need for selection in different environments. Three possible mega-environments were discerned in the studied area, Mediterranean (Spain, Tunisia and Egypt), Oceanic (UK) and Continental (Austria). Córdoba (Spain) and Kafr El-Sheik (Egypt) showed as ideal environments for rust resistance screenings within Mediterranean environment. Several accessions (300, 303, 311, 313, 720, 1196 and 1271) were grouped as moderately to highly resistant in the three defined mega-environments. These accessions showed clear differences both in terms of reduced disease severity and high stability, which make them good candidates for international faba bean breeding programmes. Concerning each mega-environment, accessions 300 and 311 were the most resistant and stable ones across the Mediterranean one, followed by accessions 720, 1022, 1272, 1320 and BPL261. On the contrary other accessions (313, 452, 481 and 1196) were the most resistant in Oceanic and Continental environments. However, 452 and 481 were susceptible in the Mediterranean mega-environment. This contrasting performance across the environments was also supported by contradictory performance of the checks BPL261 and Baraca in Oceanic and Continental environments, suggesting differential virulence in rust populations, which deserves further attention.Peer reviewe

  • Prospects for durability of available resistances to fungal diseases and parasitic weeds in pea and faba bean
    2017
    Co-Authors: Rubiales Diego, Fernández-aparicio Mónica, Barilli Eleonora, Fondevilla Sara, Villegas-fernández, Ángel M., Sillero, Josefina C.
    Abstract:

    Trabajo presentado en la International Conference Advances in grain legume breeding, cultivations and uses for a more competitive value-chain, celebrada en Novi Sad (Serbia) el 27 y 28 de septiembre de 2017.Peas and faba beans, as any other crops, can be damaged by a number of diseases. Breeders have explored a range of strategies to exploit available resistances, that unfortunately use to be scarce, incomplete and of limited heritability. As a result, only cultivars with moderate levels of resistance are available to farmers in most instances. This is further complicated by the fact that several clearly distinct species (i.e. Orobanche crenata and O. foetida; Uromyces Viciae-Fabae and U. pisi; Erysiphe pisiand E. trifolii) can infect the same legume crop. Here we will revise current status of resistance in pea and faba bean to a number of fungal diseases and parasitic weeds discussing historic and recent achievements, with a special focus on potential durability.N

  • Managing on-farm biosecurity risk through pre-emptive breeding: rust of pea and lentils
    'Japanese Society of Applied Entomology & Zoology', 2017
    Co-Authors: Barilli Eleonora, Rubiales Diego, Lichtenzveig Judith, Lee Robert
    Abstract:

    Trabajo presentado en COSTWG1 / EPPN2020 workshop, celebrado en Novi Sad (Serbia) el 29 y 30 de septiembre de 2017.Rust is a significant yield constraint in the production of lentil and field pea in various regions of the world. Rust is incited by Uromyces Viciae-Fabae in lentils and in in peas under tropical conditions, while U. pisi is the principal agent causing pea rust in temperate regions. A pea and lentil germplasm collection consisting on more than 300 accessions including current elite cultivars and breeding lines selected in key rust host-spots, were evaluated in terms of rust resistance under field and controlled conditions to allow the identification of novel sources of resistance and introgression of resistant loci into locally adapted elite germplasm. Plants were artificially inoculated and were macroscopically evaluated under field conditions at Córdoba, Spain during two growing seasons. In addition, germplasm was also evaluated under controlled conditions against 4 different rust isolates from various origins. Plant responses were assessed in terms of infection type (IT) and percentage of disease severity (DS %). The most common response of pea to U. pisi was of susceptibility, with all pea accessions showing compatible reaction with mature pustules (IT=4) although 17% of them showed partial resistance associated with reduced DS (

  • Response of Vicia species to ascochyta fabae and Uromyces Viciae-Fabae
    'Czech Academy of Agricultural Sciences', 2014
    Co-Authors: Sillero, Josefina C., Rubiales Diego
    Abstract:

    A collection of 267 accessions belonging to 61 Vicia species other than V. fab a was screened under growth chamber conditions for response to Ascochyta fabae and Uromyces Viciae-Fabae, causal agents of ascochyta blight and faba bean rust, respectively. High resistance to both diseases was very frequently detected in Vicia spp. in contrast to the high susceptibility previously reported in most V. f a b a accessions. Most of the Vicia spp. accessions studied here were very resistant or even immune to A. fabae with only one per cent of the accessions allowing development of small lesions bearing pycnidia. High resistance or immunity to U. Viciae-Fabae was also frequently found in the collection, with only ten per cent of the accessions showing compatible interaction although with reduced disease severity. These findings reinforce the specificity of A. fabae and U. Viciae-Fabae and clarify the potential role of cultivated and wild Vicia spp. in the epidemiology of these faba bean diseases.Peer Reviewe

  • Resistance to rusts (Uromyces pisi and u. Viciae-Fabae) in pea
    'Czech Academy of Agricultural Sciences', 2014
    Co-Authors: Barilli Eleonora, Sillero, Josefina C., Prats Elena, Rubiales Diego
    Abstract:

    Pea is the second most important food legume crop in the world. Rust is a pea disease widely distributed, particularly in regions with warm, humid weather. Pea rust can be incited by Uromyces Viciae-Fabae and by U. pisi. U. Viciae-Fabae prevails in tropical and subtropical regions such as India and China, while U. pisi prevails in temperate regions. Chemical control of rust is possible, but the use of host plant resistance is the most desired means of rust control. In this paper we revise and discuss the occurrence and incidence of both pathogens on peas, the availability of resistance sources and the present state of the art in pea breeding against this disease.Peer Reviewe

A. Beckett - One of the best experts on this subject based on the ideXlab platform.

  • The orientation of urediniospores of Uromyces Viciae-Fabae during fall and after landing
    Mycological Research, 1998
    Co-Authors: John A. Clement, Robert Porter, A. Beckett
    Abstract:

    The orientation of individual urediniospores and spore clusters of Uromyces Viciae-Fabae , during fall and after landing in still air, was recorded using high-speed video microscopy. Individual spores and aggregates fell in a variety of orientations. On landing spore clusters attached to the substratum without rebounding or fragmenting and typically retained their orientation during fall. * Some aggregates landed and attached in orientations in which their mass was asymmetrical with respect to their point of contact. Attachment also occurred when spores fell onto spore aggregates which had previously landed on the substratum. Rate of fall was influenced by the orientation and size of cluster. When dispersed and collected on substrata under simulated field conditions, the orientation and attachment of urediniospore clusters were similar to those of aggregates deposited in still air.

  • The role of hydrophobicity in attachment of urediniospores and sporelings of Uromyces Viciae-Fabae
    Fungal Biology, 1994
    Co-Authors: John A. Clement, Robert Porter, Tariq M Butt, A. Beckett
    Abstract:

    Aggregation of urediniospores of Uromyces Viciae-Fabae was caused by their hydrophobic surfaces. Solvent extraction of the lipids from the surface of spores decreased aggregation and increased attachment of imbibed spores to hydrophilic substrata. After landing on a substratum, urediniospores oriented randomly and made contact with the surface via spines. Spine/substratum attachment was stable on hydrophilic and hydrophobic substrata even when the alignment of spore aggregates was grossly asymmetrical to the point of attachment. When incubated at 100% r.h. capillary condensation formed between the spore wall and contiguous surfaces and spores imbibed. After imbibition hydrophobic regions remained on the surface of spores. Extracellular matrix released from the germ pore and extending germ-tube contained a region of hydrophobicity at its periphery. There was a positive correlation between protein concentration in the extracellular matrix and its ability to spread on a wax surface. Hydrophobic interactions contribute to the passive and active attachment of spores and sporelings.

  • Characterization of the extracellular matrix produced in vitro by urediniospores and sporelings of Uromyces Viciae-Fabae
    Fungal Biology, 1993
    Co-Authors: John A. Clement, Tariq M Butt, A. Beckett
    Abstract:

    The composition and pattern of temporal release of extracellular matrix produced in vitro by urediniospores and sporelings of Uromyces Viciae-Fabae is presented. In shake culture, proteins, neutral sugars and uronic acids are released in a diphasic manner which correlates with stages of the germination process and decrease in culture pH. During the initial phase, prior to germ tube emergence, predominantly low-molecular-weight carbohydrates are liberated with some high-molecular-weight polypeptides. These probably originate from solubilization of the spore surface matrix and lysis of the germ pore plug. The second phase of release, concurrent with germ-tube emergence and elongation, is characterized by increasing concentrations of high-molecular-weight polypeptides, some of which may be glycosylated. Phosphatase, glycosidase, esterase and proteolytic activity is present in the matrix prior to germination and during both subsequent phases. The pattern of polymer release and the pH changes recorded may reflect differing mechanisms of synthesis and liberation which may be important both for the adhesion of sporelings to substrata and for the localization and activity of extracellular enzymes.