Genetic diversity and population structure of Zymoseptoria tritici on bread wheat in Tunisia using SSR markers

• Published in: European journal of plant pathology Vol. 163; no. 2; pp. 429 - 440
• Main Authors: Chedli, Rim Bel Hadj, Aouini, Lamia, M’Barek, Sarrah Ben, Bahri, Bochra Amina, Verstappen, Els, Kema Gerrit, H. J., Rezgui, Salah, Yahyaoui, Amor, Chaabane, Hanène
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-06-2022; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Bread; Crop production; Ecology; Genetic diversity; Genetic markers; Genetic structure; Growing season; Life Sciences; Markers; Microsatellites; Pathogens; Plant Pathology; Plant Sciences; Population; Population genetics; Population structure; Septoria tritici blotch; Variance analysis; Wheat; Zymoseptoria tritici; Tunisia; Population structure; Genetic diversity; Bread wheat
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-022-02486-x

Septoria tritici blotch (STB) caused by
Zymoseptoria tritici
is the primary biotic stress for durum wheat production in Tunisia. The present study was aimed to decipher the genetic diversity and population structure of
Z. tritici
bread wheat isolates; in the northern regions of Tunisia this pathogen infected exclusively bread wheat. A total of 162 single-spore isolates were sampled during the 2015–2016 growing season from nine naturally infected bread wheat fields at four locations in the three main wheat-growing regions in Tunisia, previously reported as hot spots for Septoria disease (Cap Bon, Bizerte, and Beja). Collected isolates were fingerprinted using twelve polymorphic microsatellite markers to assess the genetic diversity and population structure of
Z. tritici
. All the microsatellite loci were polymorphic and a high genetic diversity was observed within the whole population. The highest Nei’s index value (0.42), Shannon Index (0.84) and private allele numbers (36) were found at the El Haouaria location (Cap Bon region). Furthermore, a moderate genetic differentiation within and among the surveyed locations (73% and 27%) was confirmed by analysis of molecular variance (AMOVA). On the other hand, the STRUCTURE program was shown to be less sensitive in revealing genetic structure especially at low levels of diversity. Thus, information on the genetic structure of the pathogen population collected from bread wheat is useful for designing and implementing durable and effective management strategies.