Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2005
Publication Date: 1/5/2006
Citation: Chu, C., Faris, J.D., Friesen, T.L., Xu, S.S. 2006. Molecular mapping of hybrid necrosis genes Ne1 and Ne2 in hexaploid wheat using microsatellite markers [abstract]. Plant and Animal Genome XIV Conference. Abstract No. P280:171.
Technical Abstract: Hybrid necrosis is the gradual pre-mature death of leaves or plants in certain F1 hybrids of wheat, and it is caused by the interaction of two dominant complementary genes Ne1 and Ne2 located on chromosome arms 5BL and 2BS, respectively. To date, molecular markers linked to these genes have not been identified. We observed that the F1 hybrids from the crosses between the bread wheat variety ‘Alsen’ and four synthetic hexaploid wheat (SHW) lines (TA4152-19, TA4152-37, TA4152-44, and TA4152-60) developed at the International Maize and Wheat Improvement Center exhibited hybrid necrosis. This study was conducted to determine the genotypes of TA4152-60 and Alsen at the Ne1 and Ne2 loci, and to map the genes using microsatellite markers in F2 and backcross populations. Genetic analysis indicated that Alsen has the genotype ne1ne1Ne2Ne2 whereas the SHW lines have Ne1Ne1ne2ne2. Five and six microsatellite markers were found to be linked with Ne1 and Ne2, respectively. Two of these markers, Xbarc74 and Xbarc55, were closely linked to Ne1 (2 cM) on 5BL and Ne2 (3.3 cM) on 2BS, respectively. Both genes are relatively near their respective centromeres, but on opposite sides. Genetic linkage analysis showed that Ne1 was 40.9 cM proximal to Tsn1, a locus conferring sensitivity to a host selective toxin Ptr ToxA produced by the tan spot fungus. The closely linked microsatellite markers identified in this study can be used to genotype parental lines for Ne1 and Ne2 or to eliminate the two hybrid necrosis genes using marker-assisted selection.