Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/9/2003
Publication Date: 8/9/2003
Citation: Stack, R.W., Garvin, D.F., Hansen, J.M. 2003. Genetic characterization of FHB resistance supression conditioned by chromosome 2A of Triticum dicoccoides. Phytopathology. 93(Suppl. 1):80.
Technical Abstract: We recently reported that disomic substitution lines prepared by replacing chromosomes of 'Langdon' durum with those from T. dicoccoides (TDIC) showed highly significant differences in response to Fusarium head blight (FHB). Several of the chromosome substitution lines showed increased resistance to FHB. In addition to those, one line [LDN(DIC2A)] was highly susceptible, just as is the TDIC accession that contributed the chromosomes to the substitution lines. In F1 hybrids with other substitution lines, the gene(s) on 2A behaves as a "susceptibility gene" that acts in an additive manner. In most F1 hybrids involving the LDN(DIC-2A), the FHB score was intermediate between the parents. However, in F2 populations derived from crosses to FHB resistant lines, the FHB resistance frequency distribution suggests that the gene(s) on chromosome 2A not only confer increased FHB susceptibility, but also suppress the effect of FHB resistance genes.