Abstract
Knowledge about the genetic variation of bristle oat (Avena strigosa Schreb.) cultivars is helpful for the development of conservation strategies to molecularly assist selection to improve the introduced germplasm in the Tunisian environment. The present study examines the genetic diversity among 22 accessions of A. strigosa and clarifies its phylogenic relationships to analyze the domestication of these well-adapted ecotypes. Twenty-two accessions of diploid A. strigosa sampled from 22 various geographical locations were analyzed with 20 universal inter-simple sequence repeat (ISSR) primers. Twelve morpho-agronomic traits were scored and all data were compiled to establish the repartition of the total ISSR variation and to analyze the genetic structure of the accessions under study. Out of 275 bands, 252 were recorded as polymorphic. The analysis of molecular variance revealed that 91% of the variation was within groups of accessions according to their geographic origins. In addition, three analyses (Bayesian, principal component analysis, and unweighted pair group method with arithmetic mean) revealed a confused distribution, independent of the geographic origin. Therefore, it may be concluded that the bristle oat accessions are interrelated in spite of their agronomic divergence. Avena strigosa may be a potential forage crop that is suited to marginal Tunisian environments.