Single Seed Descent (ssd) a tool to exploit the natural diversity to increase durum wheat sustainability and its adaptation to climate changes

A large wealth of genetic diversity is present in the diversity centers of durum wheat. However, modern breeding selection methods are mostly based on improvement of élite lines and this limits the genetic pool which breeders can exploit for the production of new varieties ready to face the predicted climate changes and the demand for reduced inputs. In terms of durum wheat sustainability, the main goal of modern breeding is the production of new varieties carrying new adaptation traits to both abiotic and biotic stress as well as an improved nitrogen use efficiency (NUE) in order reduced lands pollution. The desired traits are often found in landraces still cultivated in situ or stored ex situ in germplasm collections. The Eurisco database totals over 17,000 Triticum durum or synonyms accessions, some 6,800 of which are reported to be traditional varieties and/or landraces. The usefulness of these resources is incontestable, but, at the same time, their great number hampers the possibility to explore in depth their genepool. The challenge is to reduce the number of genotypes to be screened for new useful traits, while maintaining a good representation of the genetic background. A possible approach to reduce the number of genotypes to be assessed is the constitution of a working durum wheat collection assembled by mean of a single seed descent (SSD) approach. In the present contribution we report on the constitution and characterization of a durum wheat SSD working collection worth of a handy number of genotypes. Moreover, the results of a phenotyping experiment of the SSD collection growth under different regimes of nitrogen fertilization will be presented.