Genomic Tools for the Study of the Adaptation of Barley Crop to Climatic Constraints

The Nure x Tremois (NT) population of doubled-haploid lines has been exploited in order to map QTLs for adaptation of barley to climatic constraints. The winter parent - Nure - Italian two-rowed feed-barley cultivar, has a wide range of adaptability, including South European environments. The spring parent - Tremois - French two-rowed malting variety is adapted to fertile environments. Multilocational irrigated vs. non-irrigated field trials of the NT population have been carried out during two years (2003/04 and 2004/05) in Mediterranean Europe, North Africa and West Asia to map QTLs (Quantitative Trait Loci) of yield and drought adaptation traits, under the frame of the European MABDE project. The NT mapping population also represents a valuable resource for genomic analysis of winterhardiness-related traits. The two major loci for low temperature tolerance (Fr-H1 and Fr-H2) were found to segregate on the long arm of chromosome 5H. Moreover, QTLs controlling heading date under controlled photoperiod and vernalization conditions were placed on chromosomes 1H, 2H, 4H and 5H. The agronomic behaviour of the groups of DH lines differentiated for alleles carried at the QTL markers was surveyed. Candidate genes (CGs) involved in barley response to abiotic stresses and plant development have been placed on the NT map, as well. The co-location of QTLs along with CGs putatively related to plant adaptation to environmental conditions is presented and discussed.