Rastogi and Ohri . Silvae Genetica (2020) 69, 13 - 19 13 Chromosome Numbers in Gymnosperms - An Update Shubhi Rastogi and Deepak Ohri Amity Institute of Biotechnology, Research Cell, Amity University Uttar Pradesh, Lucknow Campus, Malhaur (Near Railway Station), P.O. Chinhat, Luc know-226028 (U.P.) * Corresponding author: Deepak Ohri, E mail:
[email protected],
[email protected] Abstract still some controversy with regard to a monophyletic or para- phyletic origin of the gymnosperms (Hill 2005). Recently they The present report is based on a cytological data base on 614 have been classified into four subclasses Cycadidae, Ginkgoi- (56.0 %) of the total 1104 recognized species and 82 (90.0 %) of dae, Gnetidae and Pinidae under the class Equisetopsida the 88 recognized genera of gymnosperms. Family Cycada- (Chase and Reveal 2009) comprising 12 families and 83 genera ceae and many genera of Zamiaceae show intrageneric unifor- (Christenhusz et al. 2011) and 88 genera with 1104 recognized mity of somatic numbers, the genus Zamia is represented by a species according to the Plant List (www.theplantlist.org). The range of number from 2n=16-28. Ginkgo, Welwitschia and Gen- validity of accepted name of each taxa and the total number of tum show 2n=24, 2n=42, and 2n=44 respectively. Ephedra species in each genus has been checked from the Plant List shows a range of polyploidy from 2x-8x based on n=7. The (www.theplantlist.org). The chromosome numbers of 688 taxa family Pinaceae as a whole shows 2n=24except for Pseudolarix arranged according to the recent classification (Christenhusz and Pseudotsuga with 2n=44 and 2n=26 respectively.