Leaf micromorphology and genetic diversity analysis of Iranian <i>Hordeum</i> species using ISSR and SCoT markers

The genus Hordeum (Poaceae), of the tribe Triticeae, comprises approximately 32 species with substantial potential for barley improvement. Hordeum vulgare is an economically important cereal widely cultivated across diverse environments, from the Arctic to desert and humid regions. In this study, we analyzed 67 individuals from 11 populations representing five Iranian Hordeum species using inter‐simple sequence repeats (ISSR) and start codon targeted (SCoT) molecular markers. We evaluated the discriminatory power of these markers and identified diagnostic micromorphological traits of the abaxial leaf blade. Genetic variation and affinities among Iranian Hordeum species were assessed using molecular markers combined with micromorphology. Neighbor‐net and UPGMA analyses revealed close evolutionary relationships among Hordeum marinum , Hordeum bulbosum , and Hordeum murinum . Micromorphological examination of the abaxial leaf surface showed significant interspecific variation in both qualitative and quantitative traits. Additionally, H. bulbosum exhibited close affinities with Hordeum vulgare subsp. spontaneum and, to a lesser extent, with Hordeum brevisubulatum . While most Hordeum research has focused on biological traits, salinity tolerance, and disease resistance, breeding efforts are limited by small grain size and scarce genetic information on wild taxa. Our findings provide valuable insights for the collection, conservation, and genetic management of Hordeum germplasm, contributing to future breeding and improvement programs. Overall, this study highlights the utility of integrating molecular and micromorphological data to guide the conservation and targeted improvement of barley and related species.