Karyomorphological studies of some species of Chrysanthemum sensu lato in Egypt

Abstract

Chromosome numbers and karyotypes are presented in eight taxa in Chrysanhemum senu lato (Asteraceae). Achillea santolina, Cotula barbata and Co. cinerea had new counts for the first time. The chromosome complement of Artemisia arborescens (2n=18) consists of 14 median and four sub- median chromosomes. Achillea fragrantissima (2n=18) consists of 14 median and four sub- median chromosomes; Ach. santolina (2n=36) consists of 26 median- and ten submedian-centromeric chromosomes. Glebionis coronaria (2n=18) consists of 18 median-centromeric chromosomes; while G. coronaria var. discolor (2n= 18) has 16 median- and two submedian-centromeric chromosomes. Cotula barbata (2n=16) consists of 12 median- and four sub-median-centromeric chromosomes, while Co. cinerea (2n=18) has 14 median- and four sub-median-centromeric chromosomes. The chromosome complement of Matricaria recutita (2n=18) consists of 14 median-, two submedian- and two subterminal-centromeric chromosomes.The longest chromosome complement was Artemisia arborescens while the shortest was Cotula barbata. The length of the tetraploid chromosome complement of Ach. santolina was approximately one third shoter than the diploid Artemisia arborescens, and equal to G. coronaria.