Phenotyping of durum wheat (Triticum turgidumL.subsp. durum) development in a recombinant inbred line population

A good phenotyping of a key trait for adaptability and productivity like development is an essential pre-requisite for an integrate approach to breeding embracing physiology, molecular biology and modeling. A RIL population was grown in pots under three treatments: vernalized plants developing under long days, vernalized plants developing under short days and unvernalized plants developing under long days. Measured traits included: time to terminal spikelet, flag leaf and anthesis, final leaf number and phyllochron, number of spikelets per spike, rate and duration of tillering, maximum tiller number. The results were organized in three chapters. The first two chapters analyzed the genotypic variability in pre-anthesis phases, tillering capacity and spikelet number of durum wheat as affected by vernalization, photoperiod and earliness per se. In the third chapter the development of a sub-set of RILs was modeled by SiriusQuality2. The experimental approach utilized resulted in an accurate phenotyping and allowed to clearly distinguish between the effects of earliness per se, vernalization and photoperiod on the analyzed traits, and also to associate to each RIL a quantitative index describing its earliness per se, photoperiodic sensitivity and cold requirement. These indexes were strongly associated with the varietal parameters of the model, which was able to reproduce the phenotypic variability observed between RILs within environments.