New determinations of somatic chromosome number in cultivated and wild species of Saccharum

Thirty-one clones of Saccharum officinarum, collected from New Guinea, were analysed and the somatic chromosome number was determined. Of the 31 clones, 29 showed 2n = 80 (typical clones), while two clones, NG 77-56 and NG 77-26, were atypical with 2n = 116 and 70 respectively. Chromosome number was determined for 62 clones of S. spontaneum, available in the world germplasm collection, through root tip mitosis. Variable numbers were identified from the same area of collection. Clones collected from north-western regions (Gujarat and Rajasthan) of India showed a majority of 2n = 80 types and 2n = 64 types, whereas 62% of clones collected from Meghalaya (north-east) showed 2n = 64. This is the first time that 2n = 80 cytotypes of S. spontaneum have been reported from the western sector of India. The clones collected from Himachal Pradesh and Uttaranchal showed lower number, e. g. 2n = 56 and 2n = 60.