Mapping adaptation of barley to Mediterranean environments

Barley (Hordeum vulgare) is an important diploid model for the Triticeae. In order to study inan unique genetic system drought and cold stresses, together with malting quality, a newgenetic map based on the Nure x Tremois (NT) doubled-haploid population has beendeveloped. The winter parent - Nure - is a modern, high yielding two-rowed feed-barleycultivar released by the ISC section of Fiorenzuola. It has a wide range of adaptability,including South European environment, and it belongs to the RLT (Recommended-ListTrials) of Italy. The spring parent - Tremois - is a modern, high yielding French two-rowedmalting variety; it is adapted to fertile environments and included in the RLT.To construct a functional map for the study of the drought tolerance trait, twenty barleyabiotic stress-induced and cold-related genes were placed on the NT map. Moreover, sixtycandidate genes were collected by looking for sequences of gene families involved in droughttolerance. Amongst them genes encoding for LEA proteins, kinases and transcription factorslike DREB/CBF, MYB and bZIP are being mapped. A multilocational irrigated vs. nonirrigatedfield trial on the NT population in Mediterranean Europe, North Africa and WestAsia is being carried out in 2004 for mapping QTLs of yield and drought adaptation traits.As a valuable tool to study low temperature tolerance, two QTLs - corresponding to theVrnH1/Fr-H1 and Fr-H2 loci for frost resistance - were mapped on the long arm ofchromosome 5H (Francia et al. 2004). Fine mapping of these QTLs has been started by usinga large F2 population.Understanding the genetic loci responsible of adaptation to drought environments will allowus to select, by means of molecular markers, superior genotypes for drought tolerance.