Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 7, 2001
Publication Date: N/A
Interpretive Summary: Barley is an important crop with several uses including malting, food, and feed. When used for malting, it must pass strict quality standards. This has caused scientists who improve malting barley to use parents that are closely related with enough genetic differences to make further improvements in yield and quality traits. Although the presence of the genetic differences was known, its location on chromosomes and association with important genes were not well understood. This study was conducted to improve our understanding of the genetic nature of this precious variability in malting barley. It was found that the variability was in primarily in clusters along the chromosomes where important genes for yield and malting quality traits are presumed to be. These results will guide scientists in improving the most critical genes for further improvements in malting barley, an economically important crop.
Technical Abstract: Barley used for malting is a fine-tuned organism, and it requires breeding within narrow gene pools for realistic cultivar enhancement. Significant phenotypic advance within such narrow gene pools has been achieved and the necessary genetic variability for the breeding progress has been documented, but it was not well understood. This study was conducted to further characterize detectable genetic variability present within a select set of four closely-related malting barley cultivars using three types of molecular markers: RFLP, PCR- RAPD, and AFLP. The markers that identified polymorphism among the select malting cultivars tended to link with each other and to map in chromosomal regions associated with quantitative trait loci QTL for agronomic and malting quality traits that differed among the four cultivars. Although RFLP identified the least amount of polymorphism, the differences detected by RFLP best fit the chronology of the cultivars. These results indicate that a large amount of the genetic variability necessary for cultivar improvement may have originally been present in the breeding gene pool, but does not rule out de novo variation. Further study of populations from crosses within this narrow germplasm is needed to even further elucidate the basis of the phenotypic variability found among these select barley cultivars.