IDENTIFICATION OF THE EXTRA CHROMOSOMES IN GIEMSA STAINED SOMATIC CELLS OF PACHYTENE IDENTIFIED TRISOMICS OF SOLANUM CHACOENSE

Abstract

Four secondary trisomics, identified by pachytene analysis in Solanum chacoense Bitt., were analyzed with the Giemsa stain technique. The clones V1700.8 and V1700.24 which, according to pachytene analysis, were secondary trisomics for the long and short arm of chromosome IV, respectively, were identified as secondary trisomics for the long and short arm of chromosome C, respectively, in Giemsa stained somatic cells. Clone V1700.1, a secondary trisomic for the long arm of chromosome IX, was identified as having an extra isochromosome for the long arm of chromosome F, and clone V1700.4, a secondary trisomic for the short arm of chromosome IX, was identified as having an extra isochromosome for the short arm of chromosome F. Chromosomes IV and IX in pachytene correspond to chromosome C and F, respectively in Giesma stained somatic cells. It was possible to locate the centromeres of the chromosomes by using pairs of secondary trisomics. The morphology of the short chromosomes is described in detail to facilitate their identification.