Chromosome identification and karyotype analysis of Podophyllum hexandrum Roxb. ex Kunth using FISH.

Podophyllum hexandrum is an important high altitude medicinal plant from Himalaya. Somatic chromosomes of this species were studied to delineate and physical mapping of repetitive rDNA sites to provide landmarks in chromosome identification. The karyotype formula of this species was found to be 6m + 2sm + 2st + 2t with secondary constriction in the chromosome 1 and 7. The FISH analysis of rDNA sites showed 4 sites for 18S rDNA and 2 sites for 5S rDNA. The chromosome number 1, 2, 5 and 6 can be identified based on 18S rDNA sites in their short arm and chromosome 1 and 2 can be identified by 5S rDNA site in the centromere region. The estimated genome size of this plant is 16.07 pg (1C).