CHARACTERIZATION OF THE HEXAPLOID OAT AVENA-BYZANTINA CV KANOTA MONOSOMIC SERIES USING C-BANDING AND RFLPS

The establishment of a C-banded karyotype of hexaploid oat (Avena spp. , 2n = 6x = 42) has facilitated the cytological characterization of a monosomic series in 'Kanota', an A. byzantina (C. Koch) cultivar. The 'Kanota' series of monosomics analyzed in this study consists of only 12 of the 21 different chromosome-deficient lines possible plus potent ial translocated segments of two or three additional chromosomes. Thes e findings were confirmed by RFLP mapping data from studies in which o at probes were assigned to syntenic groups using the 'Kanota' set of m onosomic lines. Among the remaining nine monosomic lines analyzed, eig ht are missing chromosomes represented in the set of 12 unique lines a nd one line, monosomic K13, is missing a chromosome from the unique se t of 12 that possesses a cytologically detectable translocation. This same translocation, involving chromosomes 7C and 14, is found in 5 of the 21 'Kanota' monosomics. The incompleteness of the set of 'Kanota' monosomics might be due to (i) difficulty in identifying individual oa t chromosomes without C-banding, (ii) plant genotypic and phenotypic v ariability in the original source population of the 'Kanota' monosomic s, and (or) (iii) a high frequency of monosomic shifts in progency of the original 'Kanota' monosomic lines.