Tuesday, November 14, 2006 - 9:00 AM

Validation and Genetic Characterization of Three Major QTL for Fusarium Head Blight Resistance in Wheat.

Jianli Chen, Carl A. Griffey, Maroof A. Saghai-Maroof, Jody Fanelli, and Joe Paling. 419A Smyth Hall, Virginia Tech, Virginia Tech, CSES Department, Blacksburg, VA 24061-0404

This study was conducted to characterize and evaluate the effect of three major FHB QTL, previously reported on chromosomes 3AS, 3BS, and 5AS on multiple FHB resistance components in two independent studies, one involving a mapping population derived from a cross between a known resistance source W14 and a susceptible soft red winter (SRW) wheat cultivar ‘Pioneer2684’, and the other involving seventy adapted SRW wheat lines. Fine maps of the three QTL were constructed in the mapping population. Six simple sequence repeat (SSR) and four sequence-tagged site (STS) markers associated with FHB resistance in the three QTL regions were identified and then used to characterize FHB QTL marker haplotypes and their effect on FHB resistance in seventy wheat genotypes. This study confirmed that the 3AS, 3BS, and 5AS QTL were significantly associated with FHB resistance and further indicated that the 3AS and 3BS QTL have a larger effect on three FHB resistance components (type II and III resistance and resistance to Fusarium Damaged kernels) evaluated in greenhouse experiments, while the 5AS QTL has a larger effect on type I resistance evaluated in a field experiment. Six favorable marker alleles including two (fcp396 and fcp402) on 3AS, two (barc133 and STS3B142) on 3BS, and two (Xbarc117 and barc186) on 5AS are recommended for MAS of the three QTL for improved FHB resistance in wheat. Wheat lines having favorable marker alleles identified in the current study will provide breeding programs with a source of unique and adapted FHB resistant parents and some of the lines may have potential for release as cultivars.