ARS | Publication request: CHROMOSOME ENGINEERING FOR SCAB RESISTANCE IN DURUM WHEAT.

Submitted to: International Congress of Genetics Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2003
Publication Date: July 1, 2003
Citation: JAUHAR, P.P. CHROMOSOME ENGINEERING FOR SCAB RESISTANCE IN DURUM WHEAT. INTERNATIONAL CONGRESS OF GENETICS PROCEEDINGS. 2003. ABSTRACT p.156-157.

Technical Abstract: Durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB) is an important cereal used for human consumption worldwide. Its high protein content and gluten strength make it the choice wheat for preparing pasta products. It is an important crop of the Northern Plains of the United States, and is grown in several European countries, including Italy, France, Turkey, Romania, and Ukraine, and in Canada. Current durum cultivars have little resistance to Fusarium head blight (FHB), or scab, a ravaging disease caused by the fungal pathogen Fusarium graminearum. We found that a diploid wheatgrass Lophopyrum elongatum (2n = 2x = 14; EE genome) is an excellent source of FHB resistance, which could be transferred to commercial durum cultivars by hybridization coupled with manipulation of chromosome pairing. Chromosome pairing in wheat is under strict genetic control that restricts pairing to homologous partners. Promotion of homoeologous pairing (i.e., pairing between wheat and alien chromosomes) in intergeneric hybrids is a key to alien gene transfer into wheat. We have found that certain genotypes of wild grasses suppress the activity of the pairing-regulating gene, Ph1, thereby accelerating pairing among homoeologs. Adopting such a chromosome engineering, we have transferred chromatin from diploid wheatgrass into the durum genome and produced several fertile hybrid derivatives with varying degrees of scab resistance, some with only 10% infection compared to 60 to 90% in parental durum cultivars. Using fluorescent genomic in situ hybridization, we have confirmed the integration of alien chromatin into the durum genome. The technique of chromosome engineering will be described and its value in breeding scab resistance into durum wheat will be discussed.