Molecular Plant Breeding
Monireh Rahimi; Roham Eshghi; Farshad Ebrahimpour
Volume 3, Issue 5 , February 2013, , Pages 41-48
Abstract
Drought stress is a major constraint for barley production and yield stability in rainfed ecosystems. An advanced backcross breeding strategy was used to identify quantitative trait loci (QTLs) associated with yield and yield components in a BC3 population derived from an interspecific cross between ...
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Drought stress is a major constraint for barley production and yield stability in rainfed ecosystems. An advanced backcross breeding strategy was used to identify quantitative trait loci (QTLs) associated with yield and yield components in a BC3 population derived from an interspecific cross between six-rowed spring barley (H. vulgare) ‘Azhul’ and wild barley (H. spontaneum) line ‘Spontaneum I’, under drought stress. The linkage map constructed by 170 SSR molecular markers covered a total length of about 1008.7 cM. For ten agronomical characteristics, 27 QTLs were determined. The phenotypic variation explained by individual QTLs ranged from 5.7% to 34.8% and the LOD scores ranged between 3 and 12.4. A total of 12 new QTLs were identified, where at ten QTLs the exotic introgression caused an improved trait performance, under drought stress. Four QTLs contributed by ‘Spontaneum I’ on chromosomes 1H, 2H, 3H and 7H were found to significantly increase chlorophyll content, days to maturity, flag leaf length and number of tillers per spike, respectively. In conclusion, the results of this study showed that Hordeum spontaneum, the wild progenitor of barley, is a potential source of useful genetic variation for barley breeding programs.
Molecular Plant Breeding
M Rahimi; F Ebrahimpour; R Eshghi
Volume 2, Issue 3 , January 2013, , Pages 35-48
Abstract
In this study, an F2:3 population derived from the cross between Hiberna and Pfyner was used to analyze the inheritance of yield and its components in barley by generation mean analysis and to map the corresponding QTLs (quantitative trait loci) by microsatellite markers. Generation mean analysis suggested ...
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In this study, an F2:3 population derived from the cross between Hiberna and Pfyner was used to analyze the inheritance of yield and its components in barley by generation mean analysis and to map the corresponding QTLs (quantitative trait loci) by microsatellite markers. Generation mean analysis suggested that both additive and dominance effects were important for most of the traits evaluated, but dominance and non-allelic interaction had a more pronounced effect for days to maturity, number of grains per spike, spike length and plant height. The highest heritability was obtained for number of tillers, indicating that this trait is controlled by additive effects. The additive effects played major role in the inheritance of grain yield per plant, since heritability of this trait was low. The linkage map constructed by 159 microsatellite markers covered a total length of about 1030.5 cM. Using the method of composite interval mapping 2, 4, 2, 4, 1, 4 and 7 QTLs were detected for days to maturity, number of tillers, 1000-grain weight, plant height, spike length, number of grains per spike and grain yield, respectively. Ten QTLs had corresponding occurrences with the QTLs reported earlier, indicating that these QTLs are stable across genetic backgrounds. The results of this study also showed that, grain yield per plant controls with several minor genes.
