Maroua Ouaja1, Bochra A Bahri1,2, Lamia Aouini1, Sahbi Ferjaoui3, Maher Medini4, Thierry C Marcel5, Sonia Hamza6. 1. Institut National Agronomique de Tunis, Université de Carthage, 43 Avenue Charles-Nicolle, Tunis, 1082, Tunisie. 2. Department of Plant Pathology and Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, 30223, USA. 3. Centre Régional de Recherches en Grandes Cultures (CRRGC), Route de Tunis, BP, 350, Beja, Tunisie. 4. Banque Nationale des gènes, Boulevard du Leader Yasser Arafat Z. I Charguia 1, Tunis, 1080, Tunisie. 5. UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France. 6. Institut National Agronomique de Tunis, Université de Carthage, 43 Avenue Charles-Nicolle, Tunis, 1082, Tunisie. hamza.sonia@inat.agrinet.tn.
Abstract
BACKGROUND: Tunisia is considered a secondary center of diversification of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and utilization in wheat breeding programs. Here, we investigated a diverse collection of 304 local accessions of durum wheat collected from five regions and three climate stages of central and southern Tunisia. RESULTS: Durum wheat accessions were morphologically characterized using 12 spike- and grain-related traits. A mean Shannon-Weaver index (H') of 0.80 was obtained, indicating high level of polymorphism among accessions. Based on these traits, 11 local landraces including Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H' = 0.98), spike shape (H' = 0.86), grain size (H' = 0.94), grain shape (H' = 0.87) and grain color (H' = 0.86) were the most polymorphic morphological traits. The genetic diversity of these accessions was assessed using 10 simple sequence repeat (SSR) markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high (I = 0.62; He = 0.35). In addition, population structure analysis revealed 11 genetic groups, which were significantly correlated with the morphological characterization. Analysis of molecular variance (AMOVA) showed high genetic variation within regions (81%) and within genetic groups (41%), reflecting a considerable amount of admixture between landraces. The moderate (19%) and high (59%) levels of genetic variation detected among regions and among genetic groups, respectively, highlighted the selection practices of farmers. Furthermore, Mahmoudi accessions showed significant variation in spike density between central Tunisia (compact spikes) and southern Tunisia (loose spikes with open glume), may indicate an adaptation to high temperature in the south. CONCLUSION: Overall, this study demonstrates the genetic richness of local durum wheat germplasm for better in situ and ex situ conservation and for the subsequent use of these accessions in wheat breeding programs.
BACKGROUND: Tunisia is considered a secondary center of diversification of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and utilization in wheat breeding programs. Here, we investigated a diverse collection of 304 local accessions of durum wheat collected from five regions and three climate stages of central and southern Tunisia. RESULTS: Durum wheat accessions were morphologically characterized using 12 spike- and grain-related traits. A mean Shannon-Weaver index (H') of 0.80 was obtained, indicating high level of polymorphism among accessions. Based on these traits, 11 local landraces including Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H' = 0.98), spike shape (H' = 0.86), grain size (H' = 0.94), grain shape (H' = 0.87) and grain color (H' = 0.86) were the most polymorphic morphological traits. The genetic diversity of these accessions was assessed using 10 simple sequence repeat (SSR) markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high (I = 0.62; He = 0.35). In addition, population structure analysis revealed 11 genetic groups, which were significantly correlated with the morphological characterization. Analysis of molecular variance (AMOVA) showed high genetic variation within regions (81%) and within genetic groups (41%), reflecting a considerable amount of admixture between landraces. The moderate (19%) and high (59%) levels of genetic variation detected among regions and among genetic groups, respectively, highlighted the selection practices of farmers. Furthermore, Mahmoudi accessions showed significant variation in spike density between central Tunisia (compact spikes) and southern Tunisia (loose spikes with open glume), may indicate an adaptation to high temperature in the south. CONCLUSION: Overall, this study demonstrates the genetic richness of local durum wheat germplasm for better in situ and ex situ conservation and for the subsequent use of these accessions in wheat breeding programs.
Entities:
Keywords:
Durum wheat; Genetic diversity; Landrace characterization; Local landraces; Phenotypic diversity; Population structure
Authors: Hugo R Oliveira; Michael G Campana; Huw Jones; Harriet V Hunt; Fiona Leigh; David I Redhouse; Diane L Lister; Martin K Jones Journal: PLoS One Date: 2012-05-16 Impact factor: 3.240
Authors: Angélique Gautier; Thierry C Marcel; Johann Confais; Charles Crane; Gert Kema; Frédéric Suffert; Anne-Sophie Walker Journal: BMC Res Notes Date: 2014-06-18