Characterization of the hexaploid oat Avena byzantina cv. Kanota monosomic series using C-banding and RFLPs

Abstract

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 potential translocated segments of two or three additional chromosomes. These findings were confirmed by RFLP mapping data from studies in which oat probes were assigned to syntenic groups using the 'Kanota' set of monosomic lines. Among the remaining nine monosomic lines analyzed, eight are missing chromosomes represented in the set of 12 unique lines and one line, monosomic K13, is missing a chromosome from the unique set 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 oat chromosomes without C-banding, (ii) plant genotypic and phenotypic variability in the original source population of the 'Kanota' monosomics, and (or) (iii) a high frequency of monosomic shifts in progency of the original 'Kanota' monosomic lines.Key words: oats, C-banding, RFLPs, image analysis, aneuploids.