High density genetic mapping of Fusarium head blight resistance QTL in tetraploid wheat

Abstract

Breeding for Fusarium head blight (FHB) resistance in durum wheat is complicated by the quantitative trait expression and narrow genetic diversity of available resources. High-density mapping of the FHB resistance quantitative trait loci (QTL), evaluation of their co-localization with plant height and maturity QTL and the interaction among the identified QTL are the objectives of this study. Two doubled haploid (DH) populations, one developed from crosses between Triticum turgidum ssp. durum lines DT707 and DT696 and the other between T. turgidum ssp. durum cv. Strongfield and T. turgidum ssp. carthlicum cv. Blackbird were genotyped using the 90K Infinium iSelect chip and evaluated phenotypically at multiple field FHB nurseries over years. A moderate broad-sense heritability indicated a genotype-by-environment interaction for the expression of FHB resistance in both populations. Resistance QTL were identified for the DT707 × DT696 population on chromosomes 1B, 2B, 5A (two loci) and 7A and for the Strongfield × Blackbird population on chromosomes 1A, 2A, 2B, 3A, 6A, 6B and 7B with the QTL on chromosome 1A and those on chromosome 5A being more consistently expressed over environments. FHB resistance co-located with plant height and maturity QTL on chromosome 5A and with a maturity QTL on chromosome 7A for the DT707 × DT696 population. Resistance also co-located with plant height QTL on chromosomes 2A and 3A and with maturity QTL on chromosomes 1A and 7B for the Strongfield × Blackbird population. Additive × additive interactions were identified, for example between the two FHB resistance QTL on chromosome 5A for the DT707 × DT696 population and the FHB resistance QTL on chromosomes 1A and 7B for the Strongfield × Blackbird population. Application of the Single Nucleotide Polymorphic (SNP) markers associated with FHB resistance QTL identified in this study will accelerate combining genes from the two populations.

Genetic Characterization of Multiple Components Contributing to Fusarium Head Blight Resistance of FL62R1, a Canadian Bread Wheat Developed Using Systemic Breeding

“…Currently, two major FHB resistance loci on 5AL have been reported. The first maps to the VrnA1 region, around 584.7 Mb, and has been described in both hexaploid and durum wheat (Prat et al, 2017;Sari et al, 2018;He et al, 2019). The FHB resistance 5AL QTL from FL62R1 mapped to this region, though it only had a minor effect on flowering time and plant height.…”

Potential of Genomic Selection and Integrating “Omics” Data for Disease Evaluation in Wheat

“…Phenotyping over multiple environments is routinely conducted to identify superior FHB resistant germplasm. Phenotypic selection has been successful in spite of interactions between FHB resistance loci and the environment, and the unfavorable association of FHB resistance with agronomic traits such as plant height (PH) and maturity [32][33][34][35].…”

“…The undesirable association between agronomic traits such as plant height (PH) and heading date (HD) with FHB resistance is a challenge for the application of GS. There is compelling evidence supporting the negative correlation between FHB resistance and PH and HD, which is often reflected as the co-localization of PH and HD QTL with FHB resistance QTL [32,34,35,93]. The dwarfing alleles of Rht-B1 and Rht-D1 have been associated with FHB susceptibility [94,95].…”

“…Thus, it seems realistic to develop program-specific breeder SNP chips that captures the available haplotypes at a reasonable cost. The decision on what SNPs to be included in the breeder chip could be based on the estimation of LD decay over genetic distances inferred from high-density QTL mapping studies [34,35,143] or comprehensive haplotype mapping of wheat diversity panels [136,144]. Thus, in addition to high-throughput phenotyping, advances in genotyping technologies are also shaping the future of GS including SNP arrays and DNA/RNA sequencing.…”

Biotechnological and Digital Revolution for Climate-Smart Plant Breeding

“…Recent studies report the molecular characterization of QTLs together with the identification of DNA polymorphisms underlying important traits, such as resistance to drought in barley and FHB resistance in wheat [74][75][76]. A large number of QTLs have been identified in cereals for agronomic and physiological traits under heat temperature and water stress conditions.…”