Molecular mapping of QTLs for Fusarium head blight resistance in spring wheat. II. Resistance to fungal penetration and spread

Abstract

Fusarium head blight (FHB, scab) causes severe yield and quality losses, but the most serious concern is the mycotoxin contamination of cereal food and feed. The cultivation of resistant varieties may contribute to integrated control of this fungal disease. Breeding for FHB resistance by conventional selection is feasible, but tedious and expensive. The aim of this work was to detect QTLs for combined type I and type II resistance against FHB and estimate their effects in comparison to the QTLs identified previously for type II resistance. A population of 364, F1 derived doubled-haploid (DH) lines from the cross 'CM-82036' (resistant)/'Remus' (susceptible) was evaluated for components of FHB resistance during 2 years under field conditions. Plants were inoculated at anthesis with a conidial suspension of Fusarium graminearum or Fusarium culmorum. The crop was kept wet for 20 h after inoculation by mist-irrigation. Disease severity was assessed by visual scoring. Initial QTL analysis was performed on 239 randomly chosen DH lines and extended to 361 lines for putative QTL regions. Different marker types were applied, with an emphasis on PCR markers. Analysis of variance, as well as simple and composite interval mapping, revealed that two genomic regions were significantly associated with FHB resistance. The two QTLs on chromosomes 3B (Qfhs.ndsu-3BS) and 5A (Qfhs.ifa-5A) explained 29 and 20% of the phenotypic variance, respectively, for visual FHB severity. Qfhs.ndsu-3BS appeared to be associated mainly with resistance to fungal spread, and Qfhs.ifa-5A primarily with resistance to fungal penetration. Both QTL regions were tagged with flanking SSR markers. These results indicate that FHB resistance was under the control of two major QTLs operating together with unknown numbers of minor genes. Marker-assisted selection for these two major QTLs appears feasible and should accelerate the development of resistant and locally adapted wheat cultivars.

Resistance gene analogs associated with Fusarium head blight resistance in wheat

“…Molecular mapping provides a useful tool for characterization of the effect of quantitative trait loci (QTLs) for disease resistance, localization of the QTL on a chromosome region detected in a defined population, and understanding interactions between different disease resistance QTLs (Tanksley, 1993;Paterson, 1998). To date, several QTLs for FHB resistance have been reported (Bai & Shaner, 2004), and one QTL on chromosome 3BS from Sumai 3 and its derivative Ning7840 was consistently identified to have a major effect on FHB resistance in various genetic backgrounds (Bai et al, 1999;Anderson et al, 2001;Buerstmayr et al, 2002;Guo et al, 2003). Several types of DNA markers closely linked to the QTL have been identified (Bai et al, 1999;Waldron et al, 1999;Buerstmayr et al, 2002;Guo et al, 2003;Xu & Ban, 2004), and some of them have been extensively used for marker-assisted selection (MAS) in breeding programs.…”

Maize (Zea Mays L) landraces from the southern region of Brazil: contamination by Fusarium sp, zearalenone, physical and mechanical characteristics of the kernels

“…It also has a higher probability of attack by insects, due to easiness of penetration in endosperm (Bútron et al, 2009). According to Buerstmayr et al (2003), the genetic resistance of the grain to the infection by Fusarium sp depends on two factors: resistance to the penetration of hyphae in the grain and resistance to the fungic development in endosperm of the grain. In a study carried out by Ono et al (2000) moldy grains have a positively correlation with the number of units of colony of Fusarium sp, indicating that grains with damages in pericarp is a way of fungi contamination.…”

Cloning and characterization of the ribosomal protein L3 (RPL3) gene family from Triticum aestivum

“…The obtained allele scores of the three polymorphic SNP markers were added to the pre-existing marker data for the CM-82036/Remus mapping population (Buerstmayr et al 2002(Buerstmayr et al , 2003 and/or the Frontana/ Remus population (Steiner et al 2004). The SNP markers were mapped using Mapmaker 3.0b (Lander et al 1987) with the commands 'group', 'order', 'try' and 'ripple'.…”

“…'Frontana' shows a very complex resistance pattern that predominantly acts against fungal penetration, but also passive resistance associated with morphological features was found (Steiner et al 2004). On the other hand 'CM-82036' shows a very high level of resistance to fungal penetration and spread within the plants (Buerstmayr et al 2002(Buerstmayr et al , 2003. It has been shown that a major quantitative trait locus (QTL) for FHB resistance is linked to detoxiWcation of DON by glycosylation in CM-82036 (Lemmens et al 2005).…”

“…Three cultivar speciWc single nucleotide polymorphisms (SNPs) were identiWed and used to develop molecular markers. The corresponding genes were mapped by applying the SNP markers to mapping populations, which have been generated before for the identiWcation of FHB-resistance QTLs in 'CM-82036' and 'Frontana' (Buerstmayr et al 2002(Buerstmayr et al , 2003Steiner et al 2004). Mapping of the RPL3 genes relative to previously mapped FHB resistance QTL should allow conclusions whether or not RPL3 could be involved in active FHB resistance in wheat.…”