Durum wheat breeding in Mediterranean environments - influence of climatic variables on quality traits

Two durum wheat trials were carried out in Mediterranean conditions during 2010/2011 and 2011/2012 growing seasons at Plant Breeding Station-Elvas (Portugal). The experiments were conducted under rainfed conditions however, in 2012, due to extreme drought it was necessary to use artificial irrigation between booting and mid grain filling stage. Thirty durum wheat genotypes were studied and six quality parameters were evaluated: thousand kernel weight (TKW), test weight, vitreousness, protein content, SDS test and pigment content through Minolta CR 300 Colorimeter (L*a*b*) analysis. ANOVA showed that all sources of variation for four quality traits were highly significant (P < 0.001) for both years, except for SDS volume and index b* that were not significant during the two years of trials. Environmental effects showed that total water input during grain filling, appears to affect negatively grain quality by reducing test weight, TKW and semolina yield. Maximum temperatures during the same period reduced test weight, TKW, semolina yield and pigment content (L*), but increased protein content. A negative correlation was found between protein content and test weight and a positive correlation between test weight and semolina yield. Technological trait associated with pasta quality pigment index (b*) was significant different among the genotypes.