Genetic analysis of the components of winterhardiness in barley (Hordeum vulgare L.)

Abstract

Winterhardiness in cereals is the consequence of a number of complex and interacting component characters: cold tolerance, vernalization requirement, and photoperiod sensitivity. An understanding of the genetic basis of these component traits should allow for more-effective selection. Genome map-based analyses hold considerable promise for dissecting complex phenotypes. A 74-point linkage map was developed from 100 doubled haploid lines derived from a winter x spring barley cross and used as the basis for quantitative trait locus (QTL) analyses to determine the chromosome location of genes controlling components of winterhardiness. Despite the greater genome coverage provided by the current map, a previously-reported interval on chromosome 7 remains the only region where significant QTL effects for winter survival were detected in this population. QTLs for growth habit and heading date, under 16 h and 24 h light, map to the same region. A QTL for heading date under these photoperiod regimes also maps to chromosome 2. Contrasting alleles at these loci interact in an epistatic fashion. A distinct set of QTLs mapping to chromosomes 1, 2, 3, and 5 determined heading date under 8 h of light. Under field conditions, all QTLs identified under controlled environment conditions were determinants of heading date. Patterns of differential QTL expression, coupled with additive and additive x additive QTL effects, underscore the complexity of winterhardiness. The presence of unique phenotype combinations in the mapping population suggests that coincident QTLs for heading date and winter survival represent the effects of linkage rather than pleiotropy.

Structural and functional characterization of a winter malting barley

“…The fact that 88Ab536 also has the spring allele at PPD-H2 , which confers insensitivity to short days (Faure et al 2007), is not a desirable feature for a winter barley. Short-day photoperiod sensitivity would be better for a fall-sown variety because it will keep plants at the vegetative state longer (Pan et al 1994), perhaps through the maintenance of the expression of genes conferring low-temperature tolerance (Fowler et al 2001). Therefore, the substitution of this spring allele by the winter one would be desirable for greater cold tolerance that allows expanding the potential winter malting barley acreage.…”

Allelic variations at Dhn4 and Dhn7 are associated with frost tolerance in barley

“…Location of the F primer given by Choi et al (1999) is underlined, and those of F1 and R1 are highlighted (Figure 4). The F 2 individuals derived from the Akcent × Okal cross were used to confirm the close linkage between dhn4 and dhn7 reported by Pan et al (1994) for Dictoo × Morex, and Francia et al (2004) for Nure × Tremois. As shown in Table 3, only parental homozygotes or double heterozygotes were detectable among the 34 segregants tested.…”

“…In barley, 13 dhn genes have been identified to date (Van Zee et al 1995;Choi et al 1999;Rodriguez et al 2005), and these are distributed across four of the seven barley chromosomes (dhn10 and dhn11 on 3H, dhn6 and dhn13 on 4H, dhn1, dhn2 and dhn9 on 5H, and dhn3, dhn4, dhn5, dhn7, dhn8 and dhn12 on 6H) . The dhn genes mapping to chromosomes 5H and 6H appear to be clustered (Pan et al 1994;Campbell & Close 1997). Allelic variation at the sequence level has been demonstrated for most of these dhn genes (Choi et al 1999;Close et al 2000;Lababidi et al 2004), with dhn4 being the most variable (Choi et al 1999).…”

Identification of quantitative trait loci associated with flowering, vegetative traits and photoperiod response in maize (Zea mays L)

“…The F3 lines homozygous for A632Ht alleles at both loci had a DTA of 92 days. Epistatic effects between QTL for flowering genes were previously detected in maize (Rebai et al, 1997), wheat (Klaimi and Qualset, 1973;Pan et al, 1994), barley , soybean (Coberet al, 1996), rice (Yamamoto et al, 2000) and Arabidopsis .…”