Karyotype and meiotic analysis of five species in the genusArtemisia

Abstract

The karyotypes and meiotic behaviour of five species in Artemisia are investigated. The results are concluded as following: A. absinthum Linn., A. sieversiana Ehrhart ex Willd. and A. annua Linn. are diploids; while A. abrotanum Linn. and A. japonica Thumb. are tetraploids. Their karyotypes consist mainly of median centromere and submedian centromere chromosomes, except that A. sieversiana, A. abrotanum and A. japonica have one, one and two pairs of subterminal centromere chromosomes. One pair of satellited chromosomes is respectively observed in A. annua, A. sieversiana and A. absinthum. All the species have a 2A type karyotype. The mean configurations per the pollen mother cells (PMCs) of A. absinthum, A. sieversiana and A. annua are 0.03I + 8.82II + 0.08IV, 1.16I + 8.26II + 0.03III + 0.06IV and 2.15I + 7.78II + 0.04III + 0.04IV; the mean configurations of A. abrotanum and A. japonica are 0.11I + 16.83II + 0.08III + 0.50IV and 0.17I + 16.67II + 0.07III + 0.57IV, respectively. The meiotic behaviour in the PMCs of all species is generally normal, however, higher frequencies of univalents are observed both in A. annua and A. sieversiana. A low frequency of quadrivalents (and trivalents) and chromosome bridges/lagging chromosomes is observed.