Interrelationships among Wheat Genes for Resistance to Hessian Fly1

Abstract

The interrelationships among genes for resistance in six cultlvars and one llne of hexaplold wheat (Triticum aestivum L. aestivum group) of three biotypes of Hessian fly (Mayetiola destructor Say) were analyzed using reactions of F, lines or backcrosses plant progenies at 20 C. Chi‐square goodness‐of‐fit tests were used to test genetic hypotheses. Recombination frequencies and standard errots were determined using the maximum fikelihood method.Three hexaploid wheats, Purdue 4835A4‐6, ‘Knox 62’, and ‘Lathrop’ have resistances to biotypes A and B of Hessian fly derived from PI 94587 tetraploid durum wheat (T. durum L. durum group). The single dominant gene pair H6‐H6, which also confers resistance in Knox 62 and Purdue 4835A4‐6, governs Lathrop's resistance. PurPurdue selection 822‐34 has a single dominant gene pair derived from ‘Elva’ (T. turgidum L. durum group) for resistance to biotype D of Hessian fly. The resistance was found to be inherited independently of the H5H5 gene pair in ‘Abe’. The new gene for resistance was assigned the symbol H9 H9 was linked to H3 (on chromosome 5A) with a recombination frequency of 0.155±0.048. This places H3, H6, and H9 on chromosome 5A but the gene order was not established. The genotypes of ‘Arthur 71’ and Abe were found to be H3H3 H5H5. We established that H5 is independent of the linkage block containing H3, H6, and H9.