Molecular and genetic characterization of Fusarium head blight resistance in winter wheat Centenaire
(2012)
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- (en) Fusarium head blight (FHB) is a devastating disease of wheat (Triticum aestivum L.) with worldwide economic and health impact caused by a group of trichothecene producing Fusarium species with Fusarium graminearum being the most prevalent. Breeding wheat resistant to FHB is one of the best strategies to minimize crop and grain quality losses due to the pathogen. However, the numbers of reported FHB resistance sources are limited including mostly spring genotypes and as well the molecular events leading to FHB resistance are still poorly understood. In the present work, we initiated a study on molecular and genetic characterization of FHB-resistant winter wheat genotype Centenaire exhibiting Type II resistance. The molecular aspect of this thesis was identification and characterization of putatively candidate defense genes expressed in Centenaire during F. graminearum infection using suppression subtractive hybridization. Forty three differentially expressed sequences were identified as up-regulated in the resistant germplasm due to the infection in the first 72 hours post-inoculation. Time-course expression study confirmed that some of the newly identified transcripts were differentially expressed between resistant and susceptible wheat accessions and they were related to metabolic pathways with potential role in resistance. Thirty out of forty three gene candidates were assigned to the corresponding wheat chromosomes and several were localized in the regions known to harbor quantitative trait loci for head blight resistance. In the present thesis we reported the identification of five new full-size ATP-binding cassette transporters G (ABCG) subfamily differentially expressed in wheat genotypes with contrasting resistance to head blight. The obtained results emphasize the potential involvement of ABCG transporters in wheat resistance to FHB, at least in part through the detoxification of the pathogen-produced mycotoxin deoxynivalenol. In addition, evidences that ABCB and ABCC transporter subfamilies may be also involved in resistance mechanisms were shown. Molecular markers were used to study the genetic basis of the quantitative resistance to FHB in wheat population B360 derived from cross between Centenaire x Robigus and consisting of 148 individual lines. Considering marker segregation data and phenotypic observation for each line from population B360 in different environments allowed us to identify eight microsatellite markers on chromosomes 1B, 2B, 3A, 4B, 5A and 6B linked to quantitative trait loci for FHB resistance. The results presented in this work point out possible molecular mechanisms involved in resistance to head blight. Identification of microsatellite markers linked to quantitative trait loci for FHB resistance propose winter genotype Centenaire as a source for head blight resistance with possible use in wheat breeding programs.
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Muhovski, Y. (2012). Molecular and genetic characterization of Fusarium head blight resistance in winter wheat Centenaire. https://hdl.handle.net/2078.5/160420