Cytological Studies in Some North Indian Labiatae

抄録

Cytological investigations were carried out in 18 species belonging to 13 genera. Teucrium quadrifarium (n=15) represents the first chromosome count for the species. New cytological types were observed in Ocimum canum (n=32+0-4B), O. sanctum (n=16+0-3B), Perilla ocimoides (n=14+0-2B) and in Calamintha clinopodium (n=20). For the remaining taxa, one or all the earlier chromosome reports were confirmed. Meiosis was normal in most of the taxa. The discordant chromosome numbers known in the family make it difficult to consider it as monobasic. Ocimum canum (8x) and Pogostemon plectranthoides (8x) represent the highest grade of ploidy. Intra-specific polyploidy is evident in Ocimum sanctum (2n=32, 64), O. canum (2n=24, 64, 128) and Ajuga macrosperma (2n=16, 32). Aneuploidy is equally common in the family at both the generic and specific levels.