Expression and Inheritance of Resistance of ELS 6404‐160 Durum Wheat to Hessian Fly

Abstract

ELS 6404‐160, CI17647, a durum wheat (Triticum durum Desf.) introduction from Ethiopia, was found resistant to several biotypes of Hessian fly [Mayetiola destructor (Say)]. Additional genes for resistance are needed for breeding wheat for resistance to the Hessian fly. Research was conducted on a random plant (designated as Selection 5) of ELS 6404‐160. Our objectives were to determine (i) the number of genes in ELS 6404‐160‐5 controlling resistance to biotypes B and D, (ii) if the gene(s) are different from known genes effective against biotypes B, D, and L, (iii) the pattern of resistance of ELS 6404‐160‐5 to biotypes B, C, D, and L, and (iv) the effectiveness of the resistance at three temperature regimes. Test cross progeny and F3 line analyses, conducted in greenhouses or growth chambers, indicated that ELS 6404‐160‐5 has two genes for resistance which are different from other genes known to provide resistance to biotypes D and L. Segregation of test cross progeny rows in a three segregating to one susceptible ratio following the test cross of ELS 6404‐160‐5 with susceptible D6647 indicated that resistance was governed by two genes. The occurrence of susceptible test cross progenies in test crosses following crosses of ELS 6404‐160‐ 5 with genotypes with known genes for resistance to biotype D indicated that the genes in ELS 6404‐160‐5 were different than those previously described. ELS 6404‐160‐5 is resistant to biotypes B, C, D, and L and resistance is quite stable to biotype D at three temperatures. The genes from ELS 6404‐160‐5 are designated H14 and H15. Gene H15 is closely associated with H9 on chromosome 5A; H14 may be linked to or independent of H10, which is on chromosome 5A.