Ancestral QTL Alleles from Wild Emmer Wheat Improve Drought Resistance and Productivity in Modern Wheat Cultivars.

Lianne Merchuk-Ovnat,Tzion Fahima,Tamar Krugman,Gabriel A Lidzbarsky,Frank Ordon,Vered Barak,Yehoshua Saranga

doi:10.3389/fpls.2016.00452

Lianne Merchuk-Ovnat, Tzion Fahima + Show 5 more

Open Access

https://doi.org/10.3389/fpls.2016.00452

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Abstract

Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is considered a promising source for improving stress resistances in domesticated wheat. Here we explored the potential of selected quantitative trait loci (QTLs) from wild emmer wheat, introgressed via marker-assisted selection, to enhance drought resistance in elite durum (T. turgidum ssp. durum) and bread (T. aestivum) wheat cultivars. The resultant near-isogenic lines (BC3F3 and BC3F4) were genotyped using SNP array to confirm the introgressed genomic regions and evaluated in two consecutive years under well-watered (690–710 mm) and water-limited (290–320 mm) conditions. Three of the introgressed QTLs were successfully validated, two in the background of durum wheat cv. Uzan (on chromosomes 1BL and 2BS), and one in the background of bread wheat cvs. Bar Nir and Zahir (chromosome 7AS). In most cases, the QTL x environment interaction was validated in terms of improved grain yield and biomass—specifically under drought (7AS QTL in cv. Bar Nir background), under both treatments (2BS QTL), and a greater stability across treatments (1BL QTL). The results provide a first demonstration that introgression of wild emmer QTL alleles can enhance productivity and yield stability across environments in domesticated wheat, thereby enriching the modern gene pool with essential diversity for the improvement of drought resistance.

Highlights

Wheat (Triticum spp.) is one of the world’s major food sources, providing about 20% of the calories consumed by mankind (FAO, 2011)
Our result provide the first evidence that introgression of quantitative trait loci (QTL) alleles from wild emmer wheat can enhance productivity and drought resistance in domesticated wheat
Out of the ∼13,000 single nucleotide polymorphism (SNP) markers used to genotype the introgression lines and their parents, 7880 markers were aligned with the two sub-genomes of the high density tetraploid wheat consensus map (Maccaferri et al, 2015)

Summary

Introduction

Wheat (Triticum spp.) is one of the world’s major food sources, providing about 20% of the calories consumed by mankind (FAO, 2011). 1960s to late 1980s along with advanced agronomic practices, led to substantial and rapid advances in yield (Fischer et al, 1998). This genetic improvement was mainly associated with an increased harvest index (HI) and a shift toward photoperiodinsensitivity rather than increased total biomass (Sayre et al, 1997; Ortiz et al, 2008). Developing crop cultivars with improved drought resistance is considered a sustainable and an economically viable approach to enhance crop productivity and ensure food security for the growing human population. Recent advances in molecular and genomic tools have enabled the identification of quantitative trait loci (QTLs) and diagnostic DNA markers in a wide range of crops, with the promise of accelerating crop improvement toward future challenges (Salvi and Tuberosa, 2015)

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