The use of lodicule type in assessing the origin of Avena fatuoids

Abstract

It was assumed, on the basis of earlier findings, that the Sativa-type lodicule coupled with other morphological characters is diagnostic of Avena sativa L. and that the Fatua-type lodicule is indicative of A. fatua L. or of F1 hybrids between these two taxa. Almost all of many samples of putative fatuoids that were collected in fields of cultivated oats proved to have Sativa-type lodicules and thus definitely were not of hybrid origin. Using this method, fatuoids can be recognized even when the variety from which they are supposed to have arisen is unknown. The lodicules of many chromosome aberrants were stunted but still conserved their Sativa-type configuration. The few cases of putative fatuoids with Fatua-type lodicules were interpreted as F1 hybrids of A. fatua by Fatuoid and others of A. fatua by A. sativa, depending on gross morphological characters as well. The possibility that as a result of hybrid status of a variety, genetic instability becomes a major factor causing occurrence of fatuoids has been considered.