Analysis of C‐Banding Chromosome Patterns of Sorghum

Abstract

Chromosome banding patterns can reveal the locations of specific heterochromatin characteristics for individual chromosomes in a given species. Thus, banding patterns have been used to identify individual chromosomes, to detect chromosomal structural aberrations, and to elucidate evolutionary relationships among taxonomically related species. However, such banding patterns have not been documented for any of the species in the genus Sorghum. Since these chromosomes are small and frequently difficult to distinguish, the C‐banding technique was applied to Combine Kafir 60, a cultivar of Sorghum bicolor (L.) Moench, to determine the banding patterns of the chromosome complement. While different C‐banding treatments gave somewhat different karyotypes, all gave satisfactory results for identifying individual chromosomes. All chromosomes of Combine Kafir 60 showed intensive centromeric C‐bands. Intercalary bands were present in Chromosomes 3, 4, 5, and 9, with some variations in their positions. Telomeric C‐bands were identified in both arms of Chromosomes 1, 2, and 7, and in the short arm of Chromosome 3. Chromosomes 6, 8, and 10 had only centrometic Cbands. Some C‐bands were constant in showing their characteristics and some were facultative. All 10 chromosome pairs in Combine Kafir 60 were identified by their C‐banding patterns, along with their length and arm ratios. This banding pattern can be used as the basis for detecting intraspecific chromosomal variability and an interspecific genomic relationship.