Chromosome number (2n)

Value 1440 unitless
Organism Adder's Tongue Fern
Reference Leitch IJ, Soltis DE, Soltis PS, Bennett MD. Evolution of DNA amounts across land plants (embryophyta). Ann Bot. 2005 Jan95(1):207-17.PubMed ID15596468
Primary Source 1) Khandelwal S. 1990. Chromosome evolution in the genus Ophioglossum L. Botanical Journal of the Linnean Society 102: 205–217. (2) Abraham A, Ninan CA, Mathew PM. 1962. Studies on the cytology and phylogeny of the pteridophytes VII. Observations on one hundred species of South Indian ferns. Journal of the Indian Botanical Society 41: 339–421.
Comments Ophioglossum (Adders tongue fern) is characterized by numerous, small chromosomes (1·5–4·5 µm long Abraham et al., 1962) and 2n up to 1440 (Khandelwal, 1990). Notice that this is the 2n value, i.e. counting the sister chromosomes as two separate chromosomes. Note-According to Otto et al 2000 PMID 11092833, in Ophioglossum pycnostichum 2n=1260˜84x, where researchers use x to denote the base chromosome number of a lineage and 2n to refer to the chromosome number in somatic tissue, regardless of whether an individual is diploid (2n=2x), triploid (2n=3x), etc.
Entered by Ron Milo - Admin
ID 100478