Pachytene chromosome morphology of Artemisia annua L

Morphology of the pachytene chromosomes of Artemisia annua (2n=18) has been studied in detail. In all chromosomes the heterochromatin is clustered around the centromere. On the basis of total length the chromosomes are numbered from 1 to 9, the last being the shortest of the complement. The short arm of chromosome 3 is associated with the nucleolus. Each of the nine pachytene bivalents has been identified by its distinctive morphological features such as relative length, position of centromere, symmetry of heterochromatic parts and presence of characteristic chromomeres.