Genomic Regions Associated with Tolerance to Freezing Stress and Snow Mold in Winter Wheat

Abstract

Plants grown through the winter are subject to selective pressures that vary with each year’s unique conditions, necessitating tolerance of numerous abiotic and biotic stress factors. The objective of this study was to identify molecular markers in winter wheat (Triticum aestivum L.) associated with tolerance of two of these stresses, freezing temperatures and snow mold—a fungal disease complex active under snow cover. A population of 155 F2:5 recombinant inbred lines from a cross between soft white wheat cultivars “Finch” and “Eltan” was evaluated for snow mold tolerance in the field, and for freezing tolerance under controlled conditions. A total of 663 molecular markers was used to construct a genetic linkage map and identify marker-trait associations. One quantitative trait locus (QTL) associated with both freezing and snow mold tolerance was identified on chromosome 5A. A second, distinct, QTL associated with freezing tolerance also was found on 5A, and a third on 4B. A second QTL associated with snow mold tolerance was identified on chromosome 6B. The QTL on 5A associated with both traits was closely linked with the Fr-A2 (Frost-Resistance A2) locus; its significant association with both traits may have resulted from pleiotropic effects, or from greater low temperature tolerance enabling the plants to better defend against snow mold pathogens. The QTL on 4B associated with freezing tolerance, and the QTL on 6B associated with snow mold tolerance have not been reported previously, and may be useful in the identification of sources of tolerance for these traits.

Mapping QTL conferring speckled snow mold resistance in winter wheat (<i>Triticum aestivum</i> L.)

“…Naruoka et al (2011) reported a QTL for increasing tiller numbers on chromosome 6B (QTn.mst-6B) between markers gwm 88 and gwm 193 in spring wheat, which is located on centromere region. Kruse et al (2017) also reported QTL for snow mold resistance on chromosome 6B. Based on our results, the QTL for snow mold resistance detected on chromosome 6B between markers wmc 104 and barc 136 from Ibis was also on centromere region flanking QTn.mst-6B, which indicated that both QTL are located close regions.…”

Registration of the Finch‐Eltan Winter Wheat Recombinant Inbred Line Mapping Population

“…Maximum likelihood mapping, which used five rounds of optimization, chain lengths of 1000, and termination after 100,000 chains without improvement, was used to determine the distances within linkage groups. These linkage map construction methods are also described in the supplemental materials of Kruse et al (2017). All published QTL were detected via composite interval mapping with WinQTL Cartographer version 2.5 software (Wang et al, 2012).…”

Isoform Sequencing Provides Insight Into Freezing Response of Common Wheat (Triticum aestivum L.)

“…Within 24 h of low-temperature treatment, the expression of TaSnRK2.7 gene reached the highest level. The overexpression of TaSnRK2.7 significantly increased the resistance of Arabidopsis to drought, salt, and low-temperature stress (Zhang et al, 2010 Although tolerance to subzero temperatures is often critical to winter survival, the genetic dissection of freezing tolerance of wheat has been rather limited (Kruse et al, 2017). The Vrn loci located on chromosome 5 are known to have pleiotropic effect to affect both the vernalization response and frost hardiness of winter wheat (Koemel et al, 2004).…”