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Title: Applying next-generation sequencing to enable marker-assisted breeding for adaptive traits in common bean (Phaseolus vulgaris L.)
Author: Tock, Andrew J.
ISNI:       0000 0004 6349 0000
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2017
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This research establishes molecular breeding capability for adapting common bean (Phaseolus vulgaris L.) to UK growing conditions. A high-resolution linkage map was constructed for a bi-parental recombinant inbred population (large brown x small white haricot) using genotyping-by-sequencing data. Pre-breeding material was exploited to enable genetic mapping and marker-assisted selection of essential adaptive traits, including (1) resistance to halo blight, caused by Pseudomonas syringae pathovar phaseolicola (Psph), (2) root architecture related to abiotic stress tolerance and nutrient acquisition, (3) earliness of maturity, (4) plant architecture amenable to mechanical harvest, and (5) seed coat colour of consumer interest. A 500-kb mapping interval was defined for quantitative resistance to the broadly virulent Psph race 6, a devastating bacterial pathogen that threatens global bean production with losses from halo blight. Complementary research generating high-quality draft genomes for 32 pathogenically and geographically diverse isolates of Psph identified five high-probability candidate determinants of the broad virulence of Psph race 6, including avirulence protein AvrD. Pathogenicity effectors that are highly conserved within the pathovar were identified as candidate targets for potential race-nonspecific resistance to halo blight. Putative QTL for root architecture traits associated with water and nutrient acquisition were detected on chromosome Pv07. A useful breeding strategy may be to select for larger taproot diameter in view of the comparatively high heritability of this trait. Potentially desirable alleles on Pv07 are linked in coupling phase with the dominant allele of seed coat pigmentation factor P. Identification of lines recombinant for these alleles may prove useful for the introgression of genes governing physiological resilience into white-seeded varieties adapted to UK growing conditions. Provisional QTL for morphological and reproductive traits of agronomic importance, including plant architecture, growth stage and yield, were identified using phenotypic data obtained from pilot field and polytunnel evaluations of the recombinant inbred population.
Supervisor: Not available Sponsor: Midlands Integrative Biosciences Training Partnership ; Biotechnology and Biological Sciences Research Council ; Medical and Life Sciences Research Fund
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QK Botany