Life story of Tunisian durum wheat landraces revealed by their genetic and phenotypic diversity

• Published in: bioRxiv
• Main Authors: Safa Ben Krima, Slim, Amine, Gelisse, Sandrine, Hajer Kouki, Nadaud, Isabelle, Sourdille, Pierre, Yahyoui, Amor, Sarrah Ben M'barek, Suffert, Frederic, Marcel, Thierry C
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 14.08.2020
• Subjects: Disease resistance; Genetic diversity; Genetic markers; Genetic structure; Microsatellites; Pasta; Population genetics; Septoria tritici blotch; Triticum durum
• DOI: 10.1101/2020.08.14.251157

Durum wheat (Triticum turgidum L. subsp. durum) landraces represent a prominent genetic resource for Mediterranean farming systems and breeding programs. Fourteen landraces sampled in Tunisia were genotyped with 9 microsatellite markers and characterized with 15 morphological descriptors, including resistance to the fungal disease Septoria tritici blotch (STB). The genetic diversity, nearly was as important within landraces populations (45%) than between populations (54%). It was structured in seven genetic groups and was only partly explained by the variety name or the locality of origin. Populations were also greatly diversified phenotypically (Shannon-Weaver H'=0.54) with traits related to spike and awn colours being the most diversified. Resistance to STB was either qualitative in two populations or with varying degrees of quantitative resistance in the others. A Pst-Fst comparison indicate a local adaptation of the populations. Overall, the genetic structure of Tunisian durum wheat landraces revealed a complex selection trajectory and seed exchanges between farmers. Competing Interest Statement The authors have declared no competing interest.