Santosh Bala

New chromosome reports in Lamiaceae of Kashmir (Northwest Himalaya), India.

Meiotic studies and chromosome data are imperative in order to have an overall germplasm evaluation of a taxon. In the present effort, the meiotic study is carried out in 48 populations belonging to 26 species of Lamiaceae collected from their natural habitats in Kashmir Himalaya, which forms an important part of Northwest Himalaya. Chromosome counts in the five species viz. Dracocephalum nutans (2n = 10), Lycopus europaeus (2n = 22), Marrubium vulgare (2n = 54), Nepeta nervosa (2n = 18) and Salvia sclarea (2n = 22) are first time reported from India. Besides, 17 species are cytologically evaluated for the first time from the study area—Kashmir Himalaya. In Marrubium vulgare, hexaploid cytotype (2n = 6 × =54) is reported for the first time. Also, diploid and tetraploid cytomorphovariants are observed in Calamintha vulgaris (2n = 20, 40), Elsholtzia ciliata (2n = 16, 32) and Mentha longifolia (2n = 20, 40). Various meiotic abnormalities like chromatin stickiness, cytomixis, nonsynchronous disjunction, laggards, chromatin bridges, etc. leading to pollen abnormalities have been documented for the first time in some species. The worldwide status of chromosome number data in each genus is presented.

New chromosome counts in some gentians from Western Himalayas

This study presents cytological investigations of nine species of three genera: Canscora, Gentiana and Swertia of family Gentianaceae from different geographical regions of Kashmir and Himachal Pradesh in the Western Himalayas. Chromosome numbers, detailed meiotic course and pollen fertility have been studied for each species. The study includes five new chromosome counts with first chromosome reports for Gentiana aprica (2n = 20), G. argentea var. albescens (2n = 20), G. pygmea (2n = 20) and varied reports for Swertia ciliata (2n = 26) and Swertia purpurascens (2n = 18). Some studied taxa are marked with almost normal meiosis and high pollen fertility and some are with abnormal meiotic course in the form of unoriented chromosomes, chromatin stickiness, interbivalent connections/secondary bivalent associations, laggards, bridges, etc., in minor fractions. Base numbers in the three genera are briefly discussed with respect to available world level chromosome data.