Karyomorphology and Chromosome Behaviour of a form of Eleutherine Plicata Herb. (Iridaceae) with an Aberrant Chromosome Number and a Pericentric Inversion

SUMMARYContrary to previous reports of chromosome number variation from 2n = 12 to 2n = 15 in Eleutherine plicata, we have found regularly 2n = 12 in somatic cells and in the PMC's. Further, our plants showed a sharp centromeric heteromorphism (AC/M type) in the first chromosome pair due to inversion heterozygosity. The heterotypic or bimodal karyotype, with chromosomes ranging in length from 1.26 to 5.28 μm shows a regular bivalent formation with a mean chiasma frequency of 1.93 (± 0.03) chiasmata per bivalent and 75% pollen stainability. Thus, Eleutherine plicata appears to be a disomic with x = 6 chromosomes.