Il contributo dell'analisi molecolare nella comprensione del processo di domesticamento e i benefici del grano: caratterizzazione della composizione delle subunità glutenininiche in una collezione di ecotipi di frumento duro.

Abstract

Durum wheat is the 10th most important crop worldwide owing to its annual production of 37 million tons. FAO forecasts that the annual wheat demand is expected to increase of about 2% per year in the forthcoming 40 years in spite of the limited area of production. The domestication process reduced the diversity of durum wheat of about 84%, increasing the genetic vulnerability to biotic and abiotic stresses and reducing the adaptability to the upcoming climate change. Additionally, changes in global dietary habits has caused an increasing prevalence of gluten-related disorders. The need to identify new varieties with increased yield and more sustainable management, preserving a high technological quality and healthier impact on humans, is mandatory for researchers, wheat breeders and farmers. In the present project, we chose to address this issue through the exploitation of the available biodiversity preserved in gene banks, as source of novel traits for wheat breeding. A subset a 152 genotypes derived from a worldwide germplasm collection of durum wheat, selected by Single Seed Descent, were characterized for the relative high molecular weight glutenin subunits (HMW-GS) composition since they exert a key role on flour’s quality and, in particular, on gluten strength. A combined “Omic" approach was applied on the germplasm material; traditional SDS-PAGEs, at protein level, were coupled to the exploitation of PCR-based molecular markers at genomic level and revealed a high level of variability within the genotypes. The relationship between the HMW-GS composition and the geographical origins of the germplasm was also verified allowing to trace evolutionary history of wheat diffusion and diversification. Additional in vitro tests were performed to identify and quantify gluten peptides (immunogenic and toxic) associated with celiac disease.