Location: Cereal Crops Research
Project Number: 5442-21000-037-29
Start Date: Jun 01, 2014
End Date: May 31, 2019
Fusarium head blight is a serious fungal disease that currently threats durum wheat (Triticum turgidum ssp. durum) production in North America. There is an urgent need to identify FHB-resistant genes or QTL that are useful for improving FHB resistance in durum and to develop adapted durum germplasm with improved FHB resistance. Several previous studies showed that four tetraploid wheat accessions (T. dicoccum PI 272527 and PI 41025, T. carthlicum PI 61102 and PI 94748), a hexaploid wheat line (PI 277012) carrying two 5A QTLs, a wheat line (TC67) carrying a 5A QTL from T. timopheevii, and two wheat-Elymus tsukushiensis translocation lines (TA5660 and TA5661) have certain level of Type II FHB resistance. In addition, durum cultivar ‘Divide’ is known to possess a moderate level of resistance to FHB. By using these resistance sources in crosses with durum cultivars ('Ben', 'Lebsock', 'Maier', 'Tioga', 'Carpio', and 'Joppa'), we previously developed a number of durum lines and populations, which will be used to identify FHB-resistant genes and QTL and to develop elite durum germplasm with improved FHB resistance and superior agronomic performance with improved FHB resistance. For identifying FHB-resistant QTL, a population of 200 recombinant inbred lines (RILs) from a cross between durum Divide and T. dicoccum PI 272527 will be developed and evaluated for FHB resistance in the greenhouse for three seasons and field nurseries in two locations for two years using a randomized complete block design with three replications. The population will be genotyped using the wheat 9K SNP arrays and a linkage map covering all 14 chromosomes will be then constructed with the polymorphic SNP markers. The phenotypic data and the linkage map will be used to identify QTL associated with FHB resistance. The statistical analysis will be performed using the SAS program. For QTL detection, single-factor regression analysis was performed using the entire marker data set, but for simple interval mapping and composite interval-regression mapping, a subset of the markers spaced > 2 cM apart and giving the most complete genome coverage will be used. QTL analysis will be performed using the program Windows QTL Cartographer (v2.5). For develop elite durum germplasm with improved FHB resistance, we previously selected 20 stable lines (BC1F7 and beyond) with improved FHB resistance derived from PI 272527, PI 41025, PI 61102, PI 94748, and PI 277012. We will continue evaluating these lines for FHB resistance in greenhouse and field nurseries in multiple locations. The top four lines carrying FHB resistance from PI 272527, PI 41025, PI 94748, and PI 277012 will be intercrossed to pyramid different QTL together. To transfer FHB resistance from TC67, TA5660, and TA5661, the BC1-deived lines derived from their backcrosses with Divide, Tioga, and Carpio will be evaluated for FHB resistance in greenhouse and field nurseries in multiple locations. The durum lines carrying the resistance from TC67, TA5660, and TA5661 will be crossed and backcrossed with Carpio and Joppa to improve their agronomic and quality traits.