Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/1996
Publication Date: N/A
Interpretive Summary: An important source of Hessian fly resistance in wheat was identified from the durum wheat variety Iumillo and was transferred to the spring wheat variety Marquillo by standard breeding practices. Marquillo resistance, in turn, was transferred to soft winter wheat varieties, and is effective in controlling resistance-breaking races (biotypes) of the Hessian fly found in the eastern U.S. Resistance from Marquillo was found to be controlled by a single gene, which was identified as H18. Resistance transferred from Marquillo (H18), however, was not as stable at higher temperatures as resistance carried by Iumillo, suggesting that resistance in Iumillo might be controlled by more than a single gene. The reported research demonstrated that Iumillo carries a second gene for Hessian fly resistance that is not present in Marquillo and that is independent of H18. This gene is inherited as a dominant or partially dominant gene, depending upon temperature, and is partially effective at temperatures of 23 and 26 degrees C. The identification and characterization of the second gene is an important step in providing genetic resources for improving Hessian fly resistance in wheat because it provides a source of temperature-stable resistance. Wheat varieties carrying this source of resistance would be effective in controlling the Hessian fly over a broader geographical range.
Technical Abstract: Resistance to Hessian fly, Mayetiola destructor (Say), had been reported by other researchers to be transferred from the donor 'Iumillo' durum wheat (Triticum turgidum desf.) to 'Marquillo' spring wheat (T. aestivum L.). We had observed that Iumillo demonstrated a higher proportion of resistant seedlings than Marquillo at temperatures of 21 degrees C and above, and hypothesized that Iumillo may carry a gene(s) that conditions resistance to biotype L of Hessian fly in addition to H18 that had been transferred into Marquillo. We examined the genetic basis of resistance to Hessian fly of Iumillo to determine whether more than one gene was involved in the expression of resistance. A second gene for resistance to Hessian fly, biotype D, in addition to gene H18, was identified in Iumillo in backcross (BC) F2 families. Seedlings were tested at 16, 21, 23, and 26 degrees C in a growth chamber. The second gene is inherited as a dominant or partially dominant, depending on temperature, gene independent of H18 and segragates independently of H20. Unlike H18, which is not effective above 20 degrees C, this second gene of Iumillo is partially effective in the homozygous state at temperatures of 23 and 26 degrees C.