FIELD HETEROGENEITY OF THE STRESS AFFECTS GENOTYPIC RESPONSE TO SALINITY IN DURUM-WHEAT

A large durum wheat germplasm collection was evaluated for salinity to lerance at a naturally salt-affected site in northern Syria. Given the unreplicated experimental design (modified augmented design) adopted to cope with the size of the trial and limited seed available, a study was conducted on several replications of the control cultivar 'Hauran i' used throughout the field, to assess the effects of soil heterogene ity on the genotypic response to the stress. The results confirmed pre vious observations on the great variation of salt content in naturally salinized field sites, and indicated that the variation of response t o the stress was largely due to such soil variation. Implications of u se of naturally saline sites on screening germplasm for stress toleran ce are discussed.