Efficacy of new generation fungicides against French bean rust caused by Uromyces appendiculatus

As biorationals, plant oils offer numerous advantages such as being natural products, with low ecotoxicological side effects, and high biodegradability. In particular, drying glyceride plant oils, which are rich in unsaturated fatty acids, might be promising candidates for a more sustainable approach in the discussion about plant protection and the environment. Based on this, we tested the protective and curative efficacy of an oil-in-water-emulsion preparation using drying plant oils (linseed oil, tung oil) and a semi-drying plant oil (rapeseed oil) separately and in different mixtures. Plant oils were tested in greenhouse experiments (in vivo) on green beans (Phaseolus vulgaris L.) against bean rust (Uromyces appendiculatus). We observed that a 2% oil concentration showed no or very low phytotoxic effects on green beans. Both tested drying oils showed a protective control ranging from 53–100% for linseed oil and 32–100% for tung oil. Longer time intervals of 6 days before inoculation (6dbi) were less effective than shorter intervals of 2dbi. Curative efficacies were lower with a maximum of 51% for both oils when applied 4 days past inoculation (4dpi) with the fungus. Furthermore, the results showed no systemic effects. These results underline the potential of drying plant oils as biorationals in sustainable plant protection strategies.

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Breeding for partial resistance in dry beans (Phaseolus vulgaris) to bean rust (Uromyces appendiculatus)

Annals of Applied Biology ◽

10.1111/j.1744-7348.1994.tb04138.x ◽

1994 ◽

Vol 124 (2) ◽

pp. 341-350 ◽

Cited By ~ 4

Author(s):

B R EDINGTON ◽

P E SHANAHAN ◽

F H J RIJKENBERG

Keyword(s):

Phaseolus Vulgaris ◽

Partial Resistance ◽

Uromyces Appendiculatus ◽

Bean Rust ◽

Dry Beans

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

Plant Disease ◽

10.1094/pdis.1999.83.2.108 ◽

1999 ◽

Vol 83 (2) ◽

pp. 108-113 ◽

Cited By ~ 25

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.

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Non-Mendelian and skewed segregation of DNA markers in wide crosses of the bean rust fungus,Uromyces appendiculatus

Current Genetics ◽

10.1007/bf02221580 ◽

1996 ◽

Vol 29 (2) ◽

pp. 159-167 ◽

Cited By ~ 10

Author(s):

J. P. Martinez ◽

J. V. Groth ◽

N. D. Young

Keyword(s):

Dna Markers ◽

Rust Fungus ◽

Uromyces Appendiculatus ◽

Bean Rust ◽

Wide Crosses ◽

Skewed Segregation

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Uromyces appendiculatus in Honduras: Pathogen Diversity and Host Resistance Screening

Plant Disease ◽

10.1094/pdis-02-12-0169-re ◽

2013 ◽

Vol 97 (5) ◽

pp. 652-661 ◽

Cited By ~ 10

Author(s):

Maricelis Acevedo ◽

James R. Steadman ◽

Juan C. Rosas

Keyword(s):

Uromyces Appendiculatus ◽

Bean Rust ◽

Sources Of Resistance ◽

Pathogen Diversity ◽

Major Constraint ◽

Sampling Locations ◽

Significant Difference ◽

High Incidence ◽

The Mean ◽

Virulence Diversity

Bean rust, caused by the fungus Uromyces appendiculatus, is a major constraint for common bean production worldwide. Virulence of U. appendiculatus collected from wild and cultivated Phaseolus spp. was examined in 28 locations across Honduras. Host accessions representing wild and domesticated Phaseolus spp. collected at the same sampling locations were evaluated for resistance against U. appendiculatus. In total, 91 pathotypes were identified from 385 U. appendiculatus isolates according to their virulence on each of the 12 host differentials. No significant difference in pathogen total virulence, measured as the mean disease score, was found between locations. However, significant differences were found in pathotype virulence among isolates collected from different Phaseolus spp. within a location. Moreover, when locations were compared on the basis of pathotype occurrence and frequency, differences among locations were evident. No two locations had the same pathotype composition. The most common pathotype was virulent on 9 of the 12 differential lines. A high number of resistant accessions were identified in Phaseolus coccineus and P. lunatus. Although most wild P. vulgaris accessions were highly susceptible, rust resistance was observed in P. vulgaris landraces collected from farmer's fields. Thirty-two (52%) of the accessions screened showed intermediate to high levels of resistance and, of those, 16% were P. coccineus accessions. Our findings support the hypothesis that interaction of U. appendiculatus in host populations composed of diverse Phaseolus spp. and genotypes has favored highly diverse and virulent pathotypes, creating a center for virulence diversity of the pathogen in Honduras. The high percentage of intermediate and highly resistant accessions identified in the present study supports the strategy of collecting plants from the center of diversity of a pathogen or in locations with high incidence of disease and pathogen diversity to maximize the probability of identifying new sources of resistance.

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

Australian Journal of Botany ◽

10.1071/bt9910527 ◽

1991 ◽

Vol 39 (6) ◽

pp. 527 ◽

Cited By ~ 2

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.

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