STANDARD GIEMSA C-BANDED KARYOTYPE OF RUSSIAN WILDRYE (PSATHYROSTACHYS-JUNCEA) AND ITS USE IN IDENTIFICATION OF A DELETION TRANSLOCATION HETEROZYGOTE

Ten accessions of Russian wildrye, Psathyrostachys juncea (Fisch.) Nev ski (2n = 2x = 14; NsNs), collected from different geographical region s were analyzed using the C-banding technique. C-banding pattern polym orphisms were observed at all levels, i.e., within homologous chromoso me pairs of the same plant, among different individuals within accessi ons, between different accessions of the same geographic area, and amo ng accessions of different origins. The seven homologous groups varied in the level of C-banding pattern polymorphism; chromosomes A, B, E, and F were more variable than chromosomes C, D, and G. The polymorphis ms did not hamper chromosome identification in Ps. juncea, because eac h chromosome pair of the Ns genome had a different basic C-banding pat tern and karyotypic character. A standard C-banded karyotype of Ps. ju ncea is proposed based on the overall karyotypes and C-bands in the 10 accessions. The C-bands on the Ns-genome chromosomes were designated according to the rules of nomenclature used in wheat. A deletion-trans location heterozygote of Russian wildrye was identified based on the k aryotype and C-banding patterns established. The chromosome F pair con sisted of a chromosome having the distal segment in the long arm delet ed and a translocated chromosome having the distal segment of long arm replaced by the distal segment of the long arm of chromosome E. The c hromosome E pair had a normal chromosome E and a translocated chromoso me having the short arm and the proximal segment of the long arm of ch romosome E and the distal segment of the long arm of chromosome F.