Thirty sets of reciprocal isopopulations, each with 20 Fi-derived oat lines from the BC0, BC1, and BC2 of all possible matings among five Awia slerilis L. accessions and two A. saliva cultivars, were evaluated in a replicated field trial to determine whether groat protein content was influenced by cytoplasmic inheritance and to study associations between protein content and agronomic traits. A. slerili cytoplasm had no direct effect on groat protein content, but significant interactions between the cytoplasms and nuclear genes from A. saliva and A. s1erilis were detected. Thus, the potential may exist for improving groat protein content of cultivated oats by exploiting specific intra and interspecific nucleo-cytoplasmic combinations. Generally, associations of various traits with groat protein content showed no trend for change over successive backcrosses, but phenotypic and genotypic correlations between protein percentage and all traits except harvest index tended to be larger for lines with A. s1erilis cytoplasm than those with A. saliva cytoplasm
