THE EXTENT AND STRUCTURE OF GENETIC-VARIATION IN SPECIES OF THE SITOPSIS GROUP OF AEGILOPS

The extent and structure of genetic variation in 21 populations coveri ng the five species of the Sitopsis group of Aegilops were investigate d by analysis of electrophoretically discernible water soluble leaf pr oteins. Sixteen loci were examined. All loci were polymorphic across t he five species. Over 40 per cent of the alleles were found in all fiv e species and only three rare alleles were species-specific. Genetic d iversity was high (D = 0.267) with 51 per cent of the total diversity contributed by within-population diversity, 16 per cent by diversity b etween populations within a species and 33 per cent by diversity betwe en species. Over all 21 populations the mean number of alleles per loc us per population was 1.57 and the proportion of polymorphic loci was 0.38. Aegilops speltoides was genetically distant from the other four species, Ae. bicornis, Ae, longissima, Ae. searsii and Ae. sharonensis . Aegilops sharonensis was found to be equally close to Ae. longissima and Ae. bicornis. Aegilops searsii was equally distant from Ae. longi ssima, Ae. bicornis and Ae. sharonensis.