ALLOZYME VARIATION IN ACCESSIONS OF RUSSIAN WILDRYE

Many accessions in a gene bank collection lack adequate genetic charac terization. To measure genetic variability in Russian wildrye [Psathyr ostachys juncea (Fisch.) Nevski; 2n = 2x = 14; NsNs] for effective man agement and utilization of germplasm resources, 160 plants representin g 11 accessions of this outcrossing species from five countries were a nalyzed by starch gel electrophoresis. Ten enzymes revealed 14 putativ e and scorable loci, of which 11 were polymorphic (on average, 66% of loci were polymorphic and 2.6 alleles were found per locus). High leve ls of isozyme diversity were found mainly within accessions. Fixation of the Idh allele occurred in accessions from Russia, Turkey, and Chin a, whereas polymorphisms at that locus existed in accessions from Mong olia and Iran. Allelic variation at the locus Ak-1 was only detected i n accessions of Russian origin. A large amount of allelic diversity oc curred at most polymorphic loci. Approximately 90% of the allelic dive rsity existed within accessions. Most of the accessions, except one fr om Turkey, were genetically similar. Accessions collected from Russia and Mongolia were closely related, except for accession JA 251, which is closely similar to PI 499558, an accession from Xingjiang, China.