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

2020 ◽  
Author(s):  
Safa Ben Krima ◽  
Amine Slim ◽  
Sandrine Gélisse ◽  
Hajer Kouki ◽  
Isabelle Nadaud ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Life Story ◽  
Triticum Turgidum ◽  
Phenotypic Diversity ◽  
Quantitative Resistance ◽  
Farming Systems ◽  
Septoria Tritici ◽  
Genetic Groups ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

AbstractDurum 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.

Screening of durum wheat landraces (Triticum turgidum subsp. durum) for the malting suitability

2018 ◽  
Vol 83 ◽  
pp. 101-109 ◽  
Author(s):  
Vincenzo Alfeo ◽  
Barbara Jaskula-Goiris ◽  
Ginfranco Venora ◽  
Emanuele Schimmenti ◽  
Guido Aerts ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

scholarly journals Phenotypic diversity of Tunisian durum wheat landraces

2010 ◽  
Vol 18 (1) ◽  
Author(s):  
A Sourour ◽  
K Chahine ◽  
T Youssef ◽  
SA Olfa ◽  
SA Hajer
Keyword(s):  
Durum Wheat ◽  
Phenotypic Diversity ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

scholarly journals SNP-Based Genetic Structure of Tunisian Durum Wheat Landraces and Distribution of the Resistance to Septoria Tritici Blotch

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa M. Sri ◽  
...  
Keyword(s):  
Population Structure ◽  
Durum Wheat ◽  
Eastern Mediterranean ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Mediterranean Populations ◽  
Population Structure Analysis ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.

scholarly journals Genetic Diversity of Omani Durum Wheat (Triticum turgidum sub sp. durum) Landraces

2021 ◽  
Vol 15 (1) ◽  
pp. 21-32
Author(s):  
Ali H. Al Lawati ◽  
Saleem K Nadaf ◽  
Nadiya A. AlSaady ◽  
Saleh A. Al Hinai ◽  
Almandhar Almamari ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Irrigation System ◽  
Crop Improvement ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Plant Parts ◽  
Improvement Programs ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

Introduction: The Sultanate of Oman is rich in diversity of the most important crops like wheat, which not only has a global significance but is also regarded as one of the strategic crops in the country. The country has an ancient cultivation history of both bread wheat (Triticum aestivum L.s.l.) and durum wheat (Triticum turgidum sub sp. durum) because of its characteristic location on the eastern edge of the Arabian Peninsula. Wheat landraces constitute the prime genetic resources of cultivated wheat not only in Oman but also in several MENA (the Middle East and North Africa) countries. Indigenous landraces have paramount significance for their potential utilization in crop improvement and conservation programs. Hence, the present study was undertaken to subject 17 indigenous durum wheat accessions for analyses of diversity to select parents for hybridization in national crop improvement programs. Materials and Methods: The trial was conducted consecutively for two cropping seasons (2017-2018 and 2018-2019) during winter from November to March on the layouts of a loamy soil site under sprinkler irrigation system in Augmented Design with five check varieties replicated five times randomized and distributed throughout the experimental area under spacing and crop husbandry practices as per national recommendations. The data on 9 quantitative (Plant descriptors) and 6 qualitative traits on the presence (score 1) or absence (score 0) of pigmentation on 6 plant parts were collected. These traits were subjected to both Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) to comprehend the contribution of these characters towards diversity and form prime diverse clusters from 17 indigenous durum wheat landraces to select appropriate parents for crossing. Results: The results indicated that indigenous durum wheat accessions were significantly different (p>0.05) with respect to all the quantitative characters except the number of tillers. Of 36 combinations of associations among 9 agro-morphological characters’ studied, only six correlations involving four characters viz. tiller no., spikelets/ spike, grains/spike, and grain length were found significant (p<0.05). The results of two multivariate analyses indicated the formation of four diverse clusters with different compositions of accessions, thus not supporting each other in discerning diversity. The parents were selected for hybridization for improving characters of growth for higher yield or productivity with one or two identifying markers of pigmentation on plant parts. Conclusion: The indigenous durum wheat landraces / accessions were found to be more diverse and potential for use in the national crop improvement programs for higher productivity.

scholarly journals SNP-based Genetic Structure of Tunisian Durum Wheat Landraces and Distribution of the Resistance to Septoria Tritici Blotch

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa . Sripa ◽  
...  
Keyword(s):  
Population Structure ◽  
Durum Wheat ◽  
Eastern Mediterranean ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Mediterranean Populations ◽  
Population Structure Analysis ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.

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