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GrainGenes Reference Report: TAG-109-62

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Reference
TAG-109-62
Title
Genetic control of dormancy in a Triumph/Morex cross in barley
Journal
Theoretical and Applied Genetics
Year
2004
Volume
109
Pages
62-70
Author
Prada D
[ Show all 6 ]
Abstract
Summary: Seed dormancy in barley (Hordeum vulgare L.) is one of the most important parameters affecting malting. Seed dormancy is quantitatively inherited and variously influenced by the environment. The objectives of the present study were to determine the genome location and effects of quantitative trait loci (QTLs) involved in the expression of seed dormancy in a barley cross between two varieties derived from different germplasm pools. Using a doubled-haploid population of 107 lines of the cross between the malting types Triumph (two-row, dormant) and Morex (six-row, non-dormant), seed dormancy phenotypic data sets from five environments and a 147-marker linkage map were developed in order to perform QTL analyses with simple interval mapping and simplified composite interval mapping procedures. Two different types of variables were considered for seed dormancy characterization: (1) level of dormancy induced during seed development, which was indirectly measured as germination percentage at 3 days and 7 days, GP3 and GP7 respectively; (2) rate of dormancy release in the course of a period after seed harvest (after-ripening). Different mechanisms of genetic control were detected for these two types of dormancy-related traits. A major and consistent dormancy QTL near the centromere on chromosome 7(5H) was associated with the establishment of dormancy during seed development and accounted for 52% and 33% of the variability for GP3 and GP7, respectively. Two other QTLs located in the vicinity of the vrs1 locus on chromosome 2(2H) and near the long arm telomere on chromosome 7(5H) explained 9% and 19% of variation, respectively, for the rate of dormancy release during after-ripening. Likewise, seed dormancy was assessed in an F2 population derived from the cross between two dormant types of distinct germplasm groups, Triumph (European, two-row, malt) and Steptoe (North American, six-row, feed), which showed similar but not identical genetic control for dormancy. Interestingly, there is remarkable dormancy QTL conservation in both regions on chromosome 7(5H) identified in this study and among other barley mapping populations. These widely conserved QTLs show potential as targets for selection of a moderate level of seed dormancy in breeding programs
External Databases
Pubmed: 14991108
Keyword
[ Hide all but 1 of 53 ]
aflp
afterripening
barley
breeding
breeding program
breeding programs
centromere
chromosome
conservation
control
data sets
dormancy
doubled haploid
doubled-haploid population
establishment
f-2 population
f2
feed
genome
germination
germplasm
harvest
hordeum
hordeum vulgare
inheritance
interval
linkage
linkage map
linkage-map
long arm
malt
malting
malting quality
map
mapping
mapping populations
marker
parameters
percentage
period
phenotypic data
pools
quantitative trait
quantitative trait loci
seed
seed development
seed dormancy
selection
set
telomere
trait loci
variability
vrs1 locus

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