Hessian Fly Resistance of Triticum Durum-derived Soft Winter Wheat.

Hessian fly (Mayetiola destructor Say) is one of the most destructive pests of wheat (Triticum aestivum L.) worldwide.  The most effective and economical method to control Hessian fly (Hf) is through cultivars with resistant genes.  From wheat and its wild relatives, at least thirty-two Hf-resistant genes have been identified.  The objectives of this study are to characterize the gene(s) involved in Hessian fly resistance from the Indiana line IN97219-A3-5, which has resistance to Hessian fly biotype L, and to identify linked molecular markers to facilitate marker assisted selection (MAS).  The biotype L is the most virulent of all 16 Hessian fly biotypes.  IN97219-A3-5 with the pedigree Len*3/3/Knox*2//D6647/PI 323440 derived Hf resistance from the tetraploid, Triticum durum, PI 323440.  IN97219-A3-5 is crossed to AGS2000, a Georgia line susceptible to biotype L.  The parents are screened for polymorphic SSR (simple sequence repeat) markers on chromosomes A and B.  Markers for chromosome D are excluded since IN97219-A3-5 is a durum derived source of resistance.  Phenotypic evaluation is conducted in F_2:3 families with Hessian fly biotype L pupae.  Bulked segregate analysis is used to identify SSR markers segregating with the resistant gene(s).  The markers identified with bulked segregate analysis will be tested on the F₂ lines.  Chinese Spring deletion lines will also be used to verify the chromosomal location of the gene(s).  A planting date study will also be conducted at two locations, three dates and three repetitions.  A growth chamber study will also be conducted at three temperatures: 16°C, 20°C, 23°C.