Exploiting the potential of Global Durum Panel for plant and human health

Durum wheat (Triticum turgidum L. ssp. durum (Desf.) Husn.) is the 10th most important cultivated cereal worldwide. Breeding activities developed improved varieties increasing for production, but a side effect in selecting the "best" individuals is the genetic erosion of the cultivated durum wheat varieties in comparison with their wild relatives. A recent effort to overcome this effect is the Global Durum Panel (GDP) collection developed by the international durum wheat research community. It is a freely shared wide collection of 1011 genotypes composed by modern germplasm and landraces, with a selection of emmer and primitive tetraploid wheats. The collection has been genotyped with the Illumina 90k wheat array. For our purposes, we selected a subset of the GDP collection (more than 200 genotypes), including 195 landraces. The population structure is in progress to verify: i) how much of the genetic variability from the original population has been retained in our subset collection; ii) how many groups compose the subpopulation; iii) if outliers to be discarded are present. Preliminary results indicated that the subpopulation includes four groups matching the geographic origin of the genotypes. The subcollection will be exploited to perform genome wide association studies (GWAS) to address two topics in durum wheat farming and seed processing. The first topic is related to the durum wheat disease caused by the soil-borne cereal mosaic virus (SBCMV), transmitted via roots by the plasmodiophorid protist Polymyxa graminis Led. Both new SBCMV variants and climate changes can contribute to a significant impact of infection in the near future. The use of the GDP subset collection could be very useful to identify genetic determinants of plant resistance. The subcollection will be grown in greenhouse using a soil infected by SBCMV. Infection will be evaluated by visual evaluation of symptoms and qRT-PCR. The second topic is related to human health as durum wheat is an important raw material for processed food typical of the Mediterranean region. The processing of wheat at high temperatures produces unsafe compounds, including acrylamide, a molecule known to be neurotoxic and suspected to be carcinogenic. A direct correlation between free Asparagine (fAsn) content in wheat seeds and acrylamide formation has been shown. We are investigating the subcollection to explore the natural variation for fAsn content in the seeds and to identify novel traits useful for breeding programs. A first year preliminary GWAS revealed some genomic regions putatively associated to seed fAsn content.