Photoperiod sensitivity during stem elongation as an avenue to raise potential yield in wheat

Worldwide wheat yields have been only slightly, and non-significantly, increasing during the 90's, suggesting that they may be levelling off. Considering that there is consensus that large new growing areas will be not introduced and management improvements will be increasingly harder to obtain, genetic improvement would play a more important role to keep rising wheat yields in the future than in the past. In this scenario, the use of physiological bases as a complementary tool to identifying alternative ways for breeding seems to be crucial for breaking the apparent barriers in wheat yields. In this presentation, we attempted to envisage, from published and recent unpublished evidences from our lab, using studies carried out under both controlled and field conditions, some opportunities to manipulate the rate of crop development during the late reproductive phase. This phase has been recognised as critical in terms of yield generation, and the idea of manipulating its response to photoperiod as a tool for increasing yield potential in wheat is reviewed.