Phenotypic diversity of rosemary (Salvia rosmarinus Schleid.) accessions for qualitative characters

Rosemary is one of the industrially significant crops traded over the world. Its cultivation in many countries depends on locally adapted populations rather than on the use of improved varieties. Collection and characterization of the local populations could contribute to their conservation and selection of desirable traits. Therefore, this study was undertaken to estimate the diversity of 45 rosemary accessions collected from different parts of Ethiopia using qualitative morphological traits. The frequency distribution of characters reflected the polymorphism of the studied characters, and a total of 39 phenotypic classes were observed. Shannon-weaver diversity indices estimated across accessions ranged from 0.43 to 0.99 with a mean value of 0.79, demonstrating the existence of adequate phenotypic diversity among the accessions. Estimates of diversity indices within and among growing regions revealed that intra-region diversity (0.57) exceeds inter-region diversity (0.43). Cluster analysis classified the accessions into six major clusters regardless of the accessions' geographical origin. This was consistent with the estimated within and among growing regions diversity indices. The results clearly showed the presence of considerable levels of phenotypic diversity that could be exploited as a source of a valuable gene pool for future breeding programs.