Biotechnology Assisted Wheat Breeding for Organic Agriculture
Research output: Book/Report › Ph.D. thesis
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Biotechnology Assisted Wheat Breeding for Organic Agriculture. / Steffan, Philipp Matthias.
Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, 2014.Research output: Book/Report › Ph.D. thesis
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TY - BOOK
T1 - Biotechnology Assisted Wheat Breeding for Organic Agriculture
AU - Steffan, Philipp Matthias
PY - 2014
Y1 - 2014
N2 - Common bunt of wheat is a major seed borne disease of wheat worldwide. It isof particular importance to organic farming, where systemic fungicides cannot beapplied. The knowledge about location and mechanisms of common bunt resistancein wheat is limited, and only three race specific genes have so far been mapped tochromosomes, and 9 quantitative trait loci (QTL) have been reported. Infectionwith common bunt occurs shortly after wheat sowing, however, symptoms can onlybe clearly assessed after the heading stage. Thus a long time for disease assessmentis required. The use of molecular markers for common bunt resistance may potentiallyhelp to speed up resistance breeding by shortening the long time required forphenotypic disease screening.Here, we report the results of1. an association mapping study for common bunt resistance,2. a QTL mapping study for the localization of common bunt resistance gene Bt 9and3. a yield trial assessing yield and yield stability of common bunt resistant wheatcomposite cross populations.Association mapping A collection of 248 wheat accessions was screened for commonbunt resistance during two years under field conditions. Accessions were genotypedwith diversity array technology (DArT) markers. To avoid spurious associationsdue to population stratification, DArT markers were used to estimate theextend of population stratification. Correcting for population stratification by theinclusion of a kinship matrix, a compressed mixed linear model identified two novelQTL for common bunt resistance located on wheat chromosomes 2B and 7 A. Theidentification of new resistance loci may help to broaden our understanding of commonbunt resistance in wheat, and QTL may potentially be exploited by markerassisted selection in plant breeding.QTL mapping The wheat common bunt resistance gene Bt 9 is highly effectivein Denmark, yet its chromosomal location has so far remained unknown. A doublehaploid population segregating for Bt 9 was screened phenotypically for common buntresistance reactions in three environments, and genotyped with DArTseq markers.Missing markers between typed markers were imputed on a 1cM grid along thewhole genome, and single marker regression tests located Bt 9 to the dorsal endof chromosome 6D. The development of molecular markers in tight linkage withBt 9 will offer the possibility to apply marker assisted selection for common buntresistance in wheat.Composite cross populations Race specific Bt genes may quickly be overcome bythe development of virulences in the common bunt fungi. By inter-crossing 23 wheataccessions with common bunt resistances, two wheat composite cross populations(CCP) were created. Yield of CCP was equal to parental yield, and levels of resistanceto common bunt were high in CCP. It is concluded that CCP can deliverstable yields, even under common bunt infection.
AB - Common bunt of wheat is a major seed borne disease of wheat worldwide. It isof particular importance to organic farming, where systemic fungicides cannot beapplied. The knowledge about location and mechanisms of common bunt resistancein wheat is limited, and only three race specific genes have so far been mapped tochromosomes, and 9 quantitative trait loci (QTL) have been reported. Infectionwith common bunt occurs shortly after wheat sowing, however, symptoms can onlybe clearly assessed after the heading stage. Thus a long time for disease assessmentis required. The use of molecular markers for common bunt resistance may potentiallyhelp to speed up resistance breeding by shortening the long time required forphenotypic disease screening.Here, we report the results of1. an association mapping study for common bunt resistance,2. a QTL mapping study for the localization of common bunt resistance gene Bt 9and3. a yield trial assessing yield and yield stability of common bunt resistant wheatcomposite cross populations.Association mapping A collection of 248 wheat accessions was screened for commonbunt resistance during two years under field conditions. Accessions were genotypedwith diversity array technology (DArT) markers. To avoid spurious associationsdue to population stratification, DArT markers were used to estimate theextend of population stratification. Correcting for population stratification by theinclusion of a kinship matrix, a compressed mixed linear model identified two novelQTL for common bunt resistance located on wheat chromosomes 2B and 7 A. Theidentification of new resistance loci may help to broaden our understanding of commonbunt resistance in wheat, and QTL may potentially be exploited by markerassisted selection in plant breeding.QTL mapping The wheat common bunt resistance gene Bt 9 is highly effectivein Denmark, yet its chromosomal location has so far remained unknown. A doublehaploid population segregating for Bt 9 was screened phenotypically for common buntresistance reactions in three environments, and genotyped with DArTseq markers.Missing markers between typed markers were imputed on a 1cM grid along thewhole genome, and single marker regression tests located Bt 9 to the dorsal endof chromosome 6D. The development of molecular markers in tight linkage withBt 9 will offer the possibility to apply marker assisted selection for common buntresistance in wheat.Composite cross populations Race specific Bt genes may quickly be overcome bythe development of virulences in the common bunt fungi. By inter-crossing 23 wheataccessions with common bunt resistances, two wheat composite cross populations(CCP) were created. Yield of CCP was equal to parental yield, and levels of resistanceto common bunt were high in CCP. It is concluded that CCP can deliverstable yields, even under common bunt infection.
UR - https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122787403305763
M3 - Ph.D. thesis
BT - Biotechnology Assisted Wheat Breeding for Organic Agriculture
PB - Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen
ER -
ID: 124606960