Occurrence of meiotic abnormalities and a new report of tetraploid cytotype (4x) of Artemisia nilagirica (C.B. Clarke) Pamp. from Kullu district in Northwest Himalayas

Occurrence of meiotic abnormalities and a new report of tetraploid cytotype (4x) of Artemisia nilagirica (C.B. Clarke) Pamp. from Kullu district in Northwest Himalayas

Artemisia nilagirica (Asteraceae), an important medicinal herb, is widely distributed in the hilly regions of India. On accession based analysis from Western Himalayas in Kullu district, Himachal Pradesh, we here report the presence of individuals with different chromosome counts (2n = 36, 54) and two ploidy levels (2n = 4x, 6x). Both the cytotypes showed allopolyploid meiotic behaviour with perfect 18 and 27 bivalents and equal segregation during anaphase-I. A few meiocytes in these polyploid taxa showed some meiotic irregularities involving chromatin stickiness and abnormal spindle activity leading to laggards, bridges and abnormal sporads and consequently some sterile/unstained pollen grains. Both the polyploid taxa grow under similar ecological conditions but 6x plants were observed to be more robust, grow much taller and possessed larger inflorescences. The 6x plants also differ from 4x individuals in microscopic characters like stomata and pollen grains which are larger sized in 6x compared to 4x.