scholarly journals Isolates of Uromyces appendiculatus with Specific Virulence to Landraces of Phaseolus vulgaris of Andean Origin

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Craig M. Sandlin ◽  
James R. Steadman ◽  
Carlos M. Araya ◽  
Dermot P. Coyne
Keyword(s):  
Phaseolus Vulgaris ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Rust Fungus ◽  
Distinct Group ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Banding Patterns ◽  
Highly Virulent ◽  
Specific Virulence

Five isolates of the bean rust fungus Uromyces appendiculatus were shown to be specifically virulent on bean genotypes of Andean origin. This specificity was demonstrated by the virulence of five pairs of isolates on a differential set of 30 Phaseolus vulgaris landraces. Each isolate pair was from a different country in the Americas and consisted of one Andean-specific isolate and one nonspecific isolate. Of the differential P. vulgaris landraces, 15 were of Middle American origin and 15 were of Andean origin. The Andean-specific rust isolates were highly virulent on Andean landraces but not on landraces of Middle American origin. Rust isolates with virulence to Middle American landraces were also generally virulent on Andean material; no truly Middle American-specific isolates were found. Random amplified polymorphic DNA (RAPD) analysis of the rust isolates also distinguished the two groups. Four of the Andean-specific rust isolates formed a distinct group compared to four of the nonspecific isolates. Two of the isolates, one from each of the two virulence groups, had intermediate RAPD banding patterns, suggesting that plasmagomy but not karyogamy occurred between isolates of the two groups.

scholarly journals Phenotypic and Genotypic Characterization of Uromyces appendiculatus from Phaseolus vulgaris in the Americas

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 830-836 ◽  
Author(s):  
C. M. Araya ◽  
A. T. Alleyne ◽  
J. R. Steadman ◽  
K. M. Eskridge ◽  
D. P. Coyne
Keyword(s):  
Phaseolus Vulgaris ◽  
Central America ◽  
Random Amplified Polymorphic Dna ◽  
Parallel Evolution ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Rapd Pcr ◽  
Polymerase Chain ◽  
Clear Differentiation

Populations of 90 Uromyces appendiculatus isolates were collected from throughout the Americas and evaluated for virulence on 19 standard bean rust differentials, and also on 12 landraces of Phaseolus vulgaris from South and Central America. The landrace differentials represented geographical centers of bean domestication. Three groups were observed. Two groups were isolates from centers of bean domestication and a third heterogeneous group comprised isolates from countries in South and Central America. Molecular analysis using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was also conducted on these isolates. Cluster analysis of the molecular profiles showed three groups that corresponded to those obtained by virulence tests. These results show a clear differentiation of the pathogen population along similar lines as its host and suggest parallel evolution in the bean rust pathosystem.

scholarly journals Vegetative development of Uromyces appendiculatus var. appendiculatus in Phaseolus vulgaris

1984 ◽  
Vol 62 (10) ◽  
pp. 2003-2010 ◽  
Author(s):  
R. E. Gold ◽  
K. Mendgen
Keyword(s):  
Phaseolus Vulgaris ◽  
Host Cell ◽  
Rust Fungus ◽  
Mesophyll Cell ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Palisade Parenchyma ◽  
Vegetative Development ◽  
Electron Microscopic ◽  
Mesophyll Cells

The morphology of intercellular and intracellular hyphae derived from basidiospores of Uromyces appendiculatus var. appendiculatus is described. Light and electron microscopic observations of the bean rust fungus were made on susceptible leaves of Phaseolus vulgaris from 3 to 10 days after inoculation. Following egress from invaded epidermal and palisade parenchyma cells, the fungus grew rapidly and developed extensive intercellular mycelium. An amorphous to fibrillar extracellular matrix was deposited between fungal and host cell walls. Intercellular hyphae grew closely appressed to the mesophyll cells and penetrated them to form intracellular hyphae from either a terminal or nonterminal mother cell. Intracellular hyphae were fingerlike, sometimes septate, and generally remained terminal in the invaded mesophyll cell. Occasionally the fungus exited the cell to become an intercellular hypha or an intracellular hypha in an adjacent host cell. The plant rarely exhibited a resistantlike reaction at sites of penetration into mesophyll cells.

DNA Markers Reveal Hybrids Between Two Diverse Background Genotypes in Australian Collections of the Bean Rust Fungus Uromyces appendiculatus

1994 ◽  
Vol 42 (3) ◽  
pp. 255 ◽  
Author(s):  
KS Braithwaite ◽  
JM Manners ◽  
JAG Irwin ◽  
DJ Maclean
Keyword(s):  
Comprehensive Evaluation ◽  
Genetic Recombination ◽  
Random Amplified Polymorphic Dna ◽  
Rust Fungus ◽  
Uromyces Appendiculatus ◽  
Rflp Markers ◽  
Clear Correlation ◽  
Bean Rust ◽  
Arbitrary Primers ◽  
Polymorphic Bands

Two classes of molecular markers, RFLPs (restriction fragment length polymorphisms) and RAPDs (random amplified polymorphic DNA) were used to assess genetic diversity among Australian bean rust isolates (Uromyces appendiculatus (Pers.) Unger var. appendiculatus) collected from diverse geographic locations spanning the period 1973-1990. Initially we screened 22 isolates using WLPs from five DNA probes. This was followed by analysis of a subset of 12 of these isolates using RFLPs from 10 cDNA probes and RAPDs from 10 arbitrary primers for a comprehensive evaluation of background genotype. Polymorphic bands revealed the existence of two divergent clusters of isolates, representing genotypes designated A and B. The RFLP markers showed 30% band dissimilarity between A and B, and RAPDs 16% dissimilarity. Isolates in a third cluster (genotype AB) exhibited most of the polymorphic bands present in A and B, but no unique polymorphic bands of their own, indicating that they had most probably arisen from recent hybridisation between isolates of genotype A and B. The subset of 12 isolates included 10 race phenotypes, but no clear correlation between background genotype (as assessed by RFLP and RAPD markers) and race phenotype was evident. We suggest that Australian races of bean rust have most probably evolved by a combination of mutation to virulence from common A and B background genotypes, and genetic recombination.

Isozyme evidence of pycnial fertilization by urediniospores of the bean rust fungus

1989 ◽  
Vol 67 (6) ◽  
pp. 1844-1851 ◽  
Author(s):  
John W. McCain ◽  
J. V. Groth
Keyword(s):  
Rust Fungus ◽  
Uromyces Appendiculatus ◽  
Putative Hybrid ◽  
Hybrid Progeny ◽  
Hybridization Method ◽  
Bean Rust ◽  
Genetic Studies ◽  
Maternal Parent ◽  
Infection Types ◽  
Specific Virulence

Some asexual isolates of the bean rust fungus, Uromyces appendiculatus, exhibit unusual isozyme and host-specific virulence traits. As a hybridization method not involving donor spermatia, urediniospores were applied to receptor pycnia. Aecia developed in a minority (< 10%) of the trials. Inoculations with first sibling generation urediniospores of the putative hybrid progeny on five differential bean lines often produced infection types that matched those of the maternal parent; therefore virulence did not clearly indicate successful crossing. However, urediniospore isozyme patterns containing bands from both parents for six enzymes confirmed hybridization in 7 of 14 progeny. Bands for the remaining progeny matched the maternal parent, indicating origin by selling. Thus, the electrophoretic results indicate that, in the bean rust fungus, urediniospores sometimes can act as spermatia (nuclear donors) for fertilization of pycnia. Pycnium × uredinium crossing should prove to be a useful technique for genetic studies of asexual rust populations.

Host-parasite relationships in bean cultivars of varying susceptibility to bean rust

2000 ◽  
Vol 77 (11) ◽  
pp. 1551-1559 ◽  
Author(s):  
M W Harding ◽  
J C Stutz ◽  
R W Roberson
Keyword(s):  
Phaseolus Vulgaris ◽  
Latent Period ◽  
Rust Fungus ◽  
Freeze Substitution ◽  
Infected Leaf ◽  
Bean Rust ◽  
Infection Efficiency ◽  
Host Cytoplasm ◽  
Short Latent Period ◽  
Host Parasite

Components of disease development were measured in three cultivars of Phaseolus vulgaris L. (common bean) infected with Uromyces appendiculatus (Pers.:Pers.) Unger (bean rust fungus) race O. Disease measurements and light and electron microscope data of host-parasite relationships were obtained and analyzed. Uredinial size, infection efficiency, latent period, and fungal colony radius were measured from infected bean leaves that were grown under controlled conditions. Phaseolus vulgaris cultivar Pinto 111, a highly susceptible check, displayed the largest uredinia, the highest infection efficiency, large colony radii, and a short latent period. Cultivars Early Gallatin and Kentucky Wonder (K.W.) 814 displayed moderate and low susceptibility, respectively. Cultivar Early Gallatin had smaller uredinia, reduced infection efficiency, and longer latent period when compared with cv. Pinto 111. Cultivar K.W. 814 was characterized by minute pustules, restricted colony expansion, and the longest latent period. Ultrastructural data of host-parasite relationships were collected from infected leaf tissues and prepared for transmission electron microscopy by high-pressure cryofixation and freeze substitution. In 'Pinto 111' the collars around haustorial necks were composed of a fibrillar network embedded in an electron transparent matrix. Ultrastructural observations indicated that Cultivars K.W. 814 and Early Gallatin deposited more collar material than 'Pinto 111.' Networks of tubular endomembranes developed near the host-parasite interface in the host cytoplasm of cultivars K.W. 814 and Early Gallatin. The tubules showed continuity with the extrahaustorial membrane and contained an amorphous, electron-dense material in the lumen. Tubular endomembranes were not seen in the highly susceptible cultivar Pinto 111.

A Molecular Approach to Distinguish the Bean Rust and Siratro Rust Pathogens

1991 ◽  
Vol 39 (6) ◽  
pp. 527 ◽  
Author(s):  
KS Braithwaite ◽  
JM Manners ◽  
DJ Maclean ◽  
JAG Irwin
Keyword(s):  
Rust Fungus ◽  
Repeat Unit ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Rust Disease ◽  
Dna Repeat ◽  
Total Dna ◽  
Macroptilium Atropurpureum ◽  
Genomic Probes ◽  
Rust Pathogens

Rust disease on the tropical pasture legume Macroptilium atropurpureum (siratro) is caused by Uromyces appendiculatus var. crassitunicatus. This pathogen was believed to be closely related to the bean (Phaseolus vulgaris) rust pathogen Uromyces appendiculatus var. appendiculatus. The genetic relationship between these two fungi was investigated. Total DNA hybridisations indicated that little homology exists between the high copy genomic DNA of these two rust fungi. Random genomic probes cloned from the bean rust fungus detected extensive Polymorphisms between the two, with only one probe from 17 being monomorphic. The ribosomal DNA repeat unit was also distinguished by RFLPs. It was calculated from the RFLP data that the bean rust fungus and the siratro rust fungus share only 8-14% sequence homology. The results indicate that the two fungi, although morphologically very similar, are not closely related genetically.

scholarly journals Virulence and isozyme diversity of sexual versus asexual collections of Uromyces appendiculatus (bean rust fungus)

Heredity ◽  
1995 ◽  
Vol 75 (3) ◽  
pp. 234-242 ◽  
Author(s):  
James V Groth ◽  
John W McCain ◽  
Alan P Roelfs
Keyword(s):  
Rust Fungus ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Isozyme Diversity
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