Meiotic chromosome number in a few taxa of the Lamiaceae from Lahaul-Spiti (Cold desert) and its adjoining areas of North West Indian Himalaya

Abstract

The present paper deals with the cytological sampling in 13 populations of four species such as Dracocephalum heterophyllum Benth., Micromeria biflora (L.) Hunds., Origanum vulgare L. and Scutellaria discolor Colebr. from the flora of Lahaul-Spiti and its adjoining areas of North West Indian Himalaya. The meiotic chromosome number of 2n=24 of D. heterophyllum was tetraploid (4x) report from the India for the first time, while chromosome number of 2n=48 of S. discolor (2n=48) was the first report of the tetraploid (4x) record to the world cytological database. Two species, namely, M. biflora (2n=30) and O. vulgare (2n=30) with diploid (2x) chromosome counts were cytologically reconfirmed to the Indian flora. Morphovariants were also reported in these two (i.e. M. biflora and O. vulgare) taxa. In studied genera nearly 33.33% of species in Dracocephalum L., 66.67% species in Micromeria Benth., nearly all the species in Origanum L. and 31.89% of species in Scutellaria L. are available with their cytological counts to the Indian flora.