Monogenic and epistatic resistance to bean rust infection in common bean
ABSTRACT In order to determine the relationship between resistance genes and hydrolytic enzyme induction, the interaction between two Phaseolus vulgaris cultivars (Sierra and Olathe) and two Uromyces appendiculatus races (47 and 55) were analyzed. Resistance of Sierra to race 55 was expressed as hypersensitive flecking, whereas the resistance of Olathe to race 47 was not associated with macroscopic symptoms and was classed as immunity. The Sierra/race 47 and Olathe/race 55 interactions were compatible. An analysis of a F2 population and F3 families demonstrated that a monogenic factor controlled resistance to race 47 while two genes controlled the interaction with race 55. At one locus determining resistance to race 58 resistance is dominant to susceptibility, and at the second locus hypersensitive resistance is dominant to immunity. Both alleles at the second locus are hypostatic to the susceptibility allele at the first locus. The induction of the hydrolytic enzymes β-1,3-glucanase and chitinase was monitored for the four interactions over a ten-day period. For the compatible interactions, the hydrolytic enzyme activities increased slightly over time. This pattern was also noted for the Olathe/race 55 immune-resistance interaction. In contrast, the β-1,3-glucanase and chitinase activity for the Sierra/race 55 hypersensitive-resistance interaction was significantly greater from day 2 through day 10. These results suggest the possibility that induction of hydrolytic enzyme activity may be associated with hypersensitive, but not immune resistance in the bean/bean rust interaction.
- SourceAvailable from: Vinod kumar Singh1 edited by Authored, 08/2013; Lambert Academic Publishing., ISBN: 978-3-659-44839-3
- 07/2010: pages 1 - 99; , ISBN: 9780470543672
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ABSTRACT: Common bean is an economically, nutritionally, and socially important crop. It is grown in distinct regions and different seasons around the world by subsistence level farmers with low-technology input as well as by farmers that use high input technologies. One important factor that can limit the bean growing and drastically affect grain yields is the high number of destructive pathogens that attack and cause serious damage to the crop. Among them is bean rust, incited by the fungus Uromyces appendiculatus. This disease is distributed throughout the world, but it effectively causes major production problems in humid tropical and subtropical regions. In Brazil, rust causes major losses in south, southeast, and central regions of the country. Bean rust control by resistant cultivars is an easy and economical strategy to be used in association to other rust management practices. Pyramiding of different race-specific resistance genes in association with other genes conferring adult plant resistance, slow rusting, and reduced pustule size can prolong the lifespan of a common bean cultivar by creating a more durable resistance complex against the rust pathogen. This review manuscript presents an overview on bean rust and reports some breeding efforts aiming to develop rust resistant cultivars in Brazil.Tropical Plant Pathology 10/2013; 38(5):361-374. · 0.51 Impact Factor