Identification of QTL for resistance and susceptibility to Stagonospora meliloti in autotetraploid lucerne
MetadataShow full item record
In eastern Australia and California, USA, one of the major lethal fungal diseases of lucerne (Medicago sativa) is Stagonospora root and crown rot, caused by Stagonospora meliloti. Quantitative trait loci (QTL) involved in resistance and susceptibility to S. meliloti were identified in an autotetraploid lucerne backcross population of 145 individuals. Using regression analysis and interval mapping, we detected one region each on linkage groups 2, 6 and 7 that were consistently associated with disease reaction to S. meliloti in two separate experiments. The largest QTL on linkage group 7, which is associated with resistance to S. meliloti, contributed up to 17% of the phenotypic variation. The QTL located on linkage group 2, which is potentially a resistance allele in repulsion to the markers for susceptibility to S. meliloti, contributed up to 8% of the phenotypic variation. The QTL located on linkage group 6, which is associated with susceptibility to S. meliloti, contributed up to 16% of the phenotypic variation. A further two unlinked markers contributed 5 and 8% of the phenotypic variation, and were detected in only one experiment. A total of 517 simple sequence repeat (SSR) markers from Medicago truncatula were screened on the parents of the mapping population. Only 27 (6%) SSR markers were polymorphic and could be incorporated into the autotetraploid map of M. sativa. This allowed alignment of our M. sativa linkage map with published M. truncatula maps. The markers linked to the QTL we have reported will be useful for marker assisted selection for partial resistance to S. meliloti in lucerne.
Showing items related by title, author, creator and subject.
Identification of QTL for reaction to three races of Colletotrichum trifolii and further analysis of inheritance of resistance in autotetraploid lucerneMackie, J.; Musial, J.; Armour, D.; Phan, H.; Ellwood, Simon; Aitken, K.; Irwin, J. (2007)Anthracnose, caused by Colletotrichum trifolii, is one of the most serious diseases of lucerne worldwide. The disease is managed through deployment of resistant cultivars, but new pathotypes present a challenge to the ...
Integration of EST-SSR markers of Medicago truncatula into intraspecific linkage map of lentil and identification of QTL conferring resistance to ascochyta blight at seedling and pod stagesGupta, D.; Taylor, P.; Inder, P.; Phan, H.; Ellwood, Simon; Mathur, P.; Sarker, A.; Ford, R. (2011)Microsatellite markers have been extensively utilised in the leguminosae for genome mapping and identifying major loci governing traits of interest for eventual marker-assisted selection (MAS). The lack of available ...
Analysis of candidate genes within the 3p14-p22 region of the human genome for association with bone mineral density phenotypesMullin, Benjamin H (2011)Previous studies have identified the 3p14-p22 chromosomal region as a quantitative trait locus for bone mineral density (BMD). The overall aim of this thesis is to identify the gene or genes from this region that are ...