Phenotypic diversity of barley (Hordeum vulgare L.) accessions from diverse agro-ecological zones of Ethiopia using qualitative morphological traits

Assessing phenotypic diversity within barley genetic resources is essential for conserving and utilizing the genetic resources of staple crops such as barley. However, there is insufficient knowledge about the phenotypic diversity of Ethiopian barley. Therefore, this study was conducted using an alpha lattice design with two replications, to assess the phenotypic diversity of 102 barley accessions in Ethiopia using 10 qualitative traits. Key results showed considerable genetic variability, as indicated by the Shannon-Weaver diversity index (H’), which ranged from 0.83 (glume hairiness) to 0.99 (lemma awn). The highest H’ (1.00) for specific traits was observed in different zones: kernel row number in Shewa, growth habit and spike attitude in Gojam, glume hairiness in Harerge, and lemma awn in Semen Omo. For altitude classes, H’ for lemma awn reached 1.00 at ≥ 2600 m.a.s.l. Most of the phenotypic variation was within zone of origin (71%), and within altitude classes (75%). The analysis of variance for H’ values based on the altitude classes and zone of origin showed highly significant to significant difference ( p ≤ 0.001 to p ≤ 0.05). Kernel color, lemma color, and growth habit (zone of origin), as well as lemma color, lemma awn, and lemma color at physiological maturity (altitude classes), were the most informative traits for distinguishing barley accessions and could inform selection criteria for crop improvement. The substantial phenotypic diversity observed among the accessions provides valuable opportunities for barley improvement and conservation efforts. Furthermore, future studies integrating quantitative agronomic traits and molecular markers, and genotype X environment interaction are suggested to identify superior accessions for targeted breeding programs.