ARS | Publication request: Synthesis of FHB-Tolerant Hybrid Derivatives of Durum Wheat and Durum Alien Addition Lines Involving Wheatgrass Chromosomes

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 27, 2010
Publication Date: June 3, 2011
Citation: Jauhar, P.P. 2011. Synthesis of FHB-Tolerant Hybrid Derivatives of Durum Wheat and Durum Alien Addition Lines Involving Wheatgrass Chromosomes. Meeting Proceedings. 63:21-26.

Technical Abstract: Fusarium head blight (FHB), caused primarily by the fungal pathogen Fusarium graminearum Schwabe, is one of the most serious diseases of durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB). Depending on environmental conditions favoring the spread of pathogen, the disease greatly reduces grain yield and quality. Incorporating FHB resistance into commercial wheat cultivars would be the most appropriate means of controlling this ravaging disease. Diploid wheatgrass (Lophopyrum elongatum (Host) Á. Löve, 2n = 2x = 14; EE genome) is an excellent source of FHB resistance. In our earlier work, this grass showed a mean infection of 3.8%, compared to 60% to 90% infection in durum cultivars. Another diploid wheatgrass, Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (2n = 2x = 14; JJ genome), may also be a potential donor of FHB resistance to durum cultivars. Although these grasses are in the secondary gene pool of durum wheat, they can be easily crossed with durum cultivars using embryo rescue techniques, thereby enabling alien chromatin transfers. Moreover, because of their low chromosome number, it would be desirable to use the diploid wheatgrasses in breeding resistance into durum cultivars. Manipulation of the Ph1 system (located in chromosome 5B), that suppresses pairing among less related chromosomes, is the key to induction of homoeologous pairing and to effect alien gene transfers into durum wheat. In addition to chromosome engineering involving segments of chromosomes, another means of genomic reconstruction is to add desirable alien chromosomes into durum cultivars and produce stable disomic alien addition lines. We have produced such additions involving chromosomes of the two diploid wheatgrasses. Details of this work on fertile hybrid derivatives and stable disomic additions will be described.