Meiotic Studies and B-Chromosomes in Sedum oreades (Decne.) R. Hamet (Crassulaceae) from Alpine Regions of Northwest Indian Himalaya

Abstract

Meiotic studies carried out in the individuals of Sedum oreades (Decne.) R. Hamet (Crassulaceae), which exists at diploid level (n=11) revealed the presence of 0-4B-chromosomes, non-synchronous disjunction of bivalents, chromatin bridges, and laggards as well as some pollen sterility (8%) in the collection from Manimahesh Hills (Gauri Kund, 3930 m, Chamba district, Himachal Pradesh). The present diploid chromosome count of n=11 is the first report from India but agrees with the earlier report from Nepal Himalayas. The presence of B-chromosomes in the species is also the first record for the species. The paper here discusses in detail the course of meiosis and the effect of B-chromosomes and other meiotic abnormalities on meiotic course and pollen fertility.