Assessment of Genetic Diversity and Fusarium Root Rot Response in Turkish Bread Wheat

Abstract

Understanding the genetic diversity and population structure of bread wheat germplasm is essential for effective breeding and conservation strategies. This study evaluated 96 bread wheat genotypes from Turkiye-including advanced lines, commercial cultivars, and landraces-using Start Codon Targeted (SCoT) and inter-Primer Binding Site (iPBS) retrotransposon markers. Six SCoT and four iPBS primers generated 81.32% and 75.59% polymorphic bands, respectively, producing clear and reproducible profiles. The average polymorphism information content was 0.19 for both marker systems, with resolving power values of 3.13 (SCoT) and 2.35 (iPBS). Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis grouped the genotypes into two major clusters with 41% overall similarity. Principal coordinate analysis (PCoA) clearly illustrated the genetic differentiation among the genotypes. Analysis of molecular variance (AMOVA) revealed that 69% of genetic variation was distributed within populations. Pathogenicity assays revealed differential disease responses among 21 genotypes to Fusarium culmorum isolate, with the cultivar Empire exhibiting moderate resistance. SCoT and iPBS markers effectively revealed genetic variation and supported the exploitation of promising genotypes for resistance breeding. The identification of genetically distinct and moderately resistant genotypes underscores the potential of Turkish wheat germplasm to support future breeding efforts.