Integrated assessment of some productive traits and molecular diversity using ISSR markers in bread wheat

This study aimed to examine the quantitative and molecular genetic variation of four bread wheat (Ibaa99, Furat, Bohooth22, and Mawada), based on yield traits and ISSR markers. The field experiment took place in Najaf Governorate (Iraq), during the 2024 - 2025 winter growing season. It used a randomized complete block design (RCBD) with three replications. Analysis of variance (ANOVA) results showed highly significant differences among the studied varieties in all traits. The Bohooth22 variety recorded the highest values for number of spikes per plant (7.11), thousand-grain weight (43.5 g), number of grains per spike (52.2), and grain yield (32.3 g/plant (. Genetic parameters showed a indicates a relatively stronger genetic control, with phenotypic variation coefficients (PCV) ranging from 6.1% to 23.4% and genetic variation coefficients (GCV) ranging from 4.8% to 19.8%. The traits also exhibited relatively high broad-sense heritability values (68.3% to 71.4%), with relatively high predicted heritability for both grain-to-spike (GA = 7.82; 16.1%) and grain yield (GA = 4.98; 17.3%). The results of the ISSR technique with four primers showed 38 bands. Out of these, 26 were polymorphic, which represents 68% polymorphism. The genetic similarity coefficients ranged from 0.60 to 0.74. Cluster analysis (UPGMA) demonstrated the distinctness of the Bohooth22 genotype and its separation into an independent cluster. These results show the significance of combining quantitative genetics with ISSR markers. This approach helps identify better wheat genotypes that are suitable for breeding programs in Iraq.