Chromosomal regions controlling seedling drought resistance in Israeli wild barley, Hordeum spontaneum C. Koch

The objective of the present study was to map quantitative trait loci (QTL) controlling drought-resistance traits at seedling stage of Israeli wild barley (Hordeum spontaneum). Mapping was conducted using an F-4 mapping population derived from a cross between genotype WQ23-38 from xeric (Wadi Qilt, 144 mm annual rainfall) and MA10-30 from mesic (Maalot, 790 mm annual rainfall) environments. Obvious segregation was observed for traits including time to wilt, leaf relative elongation rate, recovery rate, shoot regrowth, osmolarity, relative water content, leaf length, and root length with the coefficient of variation ranging from 10 to 77%. Eighteen putative QTL effects were identified (at false discovery rate = 10%) by single-trait analyses and confirmed by multi-trait analysis and multiple interval mapping using a new MultiQTL package. The results of our study suggest that the xeric genotypes adopted survival strategies while the mesic genotypes adopted growth-sustain strategies to cope with drought stress.