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Theor Appl Genet (2012) 125:17511765 DOI 10.1007/s00122-012-1951-2
ORIGINAL PAPER
Mapping of QTL for Fusarium head blight resistanceand morphological and developmental traits in three backcross populations derived from Triticum dicoccum 3 Triticum durum
Maria Buerstmayr Karin Huber
Johannes Heckmann Barbara Steiner
James C. Nelson Hermann Buerstmayr
Received: 25 May 2012 / Accepted: 15 July 2012 / Published online: 25 August 2012 The Author(s) 2012. This article is published with open access at Springerlink.com
Abstract Breeding for resistance to Fusarium head blight (FHB) in durum wheat continues to be hindered by the lack of effective resistance sources. Only limited information is available on resistance QTL for FHB in tetraploid wheat. In this study, resistance to FHB of a Triticum dicoccum line in the background of three Austrian T. durum cultivars was genetically characterized. Three populations of BC1F4-
derived RILs were developed from crosses between the resistant donor line T. dicoccum-161 and the AustrianT. durum recipient varieties DS-131621, Floradur and Helidur. About 130 BC1F4-derived lines per population were evaluated for FHB response using articial spray
inoculation in four eld experiments during two seasons. Lines were genetically ngerprinted using SSR and AFLP markers. Genomic regions on chromosomes 3B, 4B, 6A, 6B and 7B were signicantly associated with FHB severity. FHB resistance QTL on 6B and 7B were identied in two populations and a resistance QTL on 4B appeared in three populations. The alleles that enhanced FHB resistance were derived from the T. dicoccum parent, except for the QTL on chromosome 3B. All QTL except the QTL on 6A mapped to genomic regions where QTL for FHB have previously been reported in hexaploid wheat. QTL on 3B and 6B coincided with Fhb1 and Fhb2, respectively. This implies that tetraploid and hexaploid wheat share common genomic regions associated with FHB resistance. QTL for FHB resistance on 4B co-located with a major QTL for plant height and mapped at the position of the Rht-B1 gene, while QTL on 7B overlapped with QTL for owering time.
Introduction
Fusarium head blight (FHB), caused by several members of the Fusarium genus, occurs frequently in small grain cereals in temperate regions throughout the world (McMullen et al. 1997). FHB leads to severe losses not only in grain yield but also in quality; contamination with toxic fungal...