Variation in Chromosome Number, Karyotype and Nuclear DNA Content of Five Species of Indian Typhonium Schott. (Araceae)—A Medicinally Important Plant

Detailed karyotype analysis of somatic chromosomes in 5 species of Typhonium Schott. of the family Araceae was carried out for the first time. The chromosome number varied from 2n=16 in T. flagelliforme to 2n=52 in T. diversifollium. Chromosome number 2n=18 and 2n=26 in T. trilobatum and T. roxburghii respectively suggest formation of anueploids during speciation. The asymmetric karyotype revealed structural alterations with 2 distinct types of chromosomes (long and very short types) as evident in different species of Typhonium. Significant variations in chromosome size were observed among the studied species. TF% revealed sub-metacentric long chromosomes in T. flagelliforme (TF value, 33%) and metacentric short chromosomes in T. diversifolium (TF value, 41%). Average chromosome length varied from 2.03 μm in T. diversifolium, a high altitude species (5000–7000 ft), to 8.68 μm in T. flagelliforme, a low land species (70–250 ft). Significant variations were observed in Interphase Nuclear Volume (INV) which varied from 142.05 μm3 in T. trilobatum to 335.02 μm3 in T. flagelliforme; nuclear DNA content varied significantly from 0.199 pg in T. diversifolium to 0.833 pg in T. flagelliforme.