Polyploidy in Gymnosperms-A Reappraisal

Abstract Recent polyploidy in gymnosperms is unusually scarce being present only 9.80 % of the 714 taxa studied cytologically. Polyploid forms are represented by sporadic seedlings and individual trees, intraspecific cultivation or wild entirely polyploid species genera. Polyploidy shows a non-random distribution different genera mostly prevalent Ephedra Juniperus , besides classic examples Sequoia Fitzroya . Remarkably, both show adaptive radiation interspecific hybridization followed while Ginkgo viable cytotypes found cultivation. Induced has not provided any tangible results past but recent attempts on certain Cupressaceae hold some promise producing cultivars for horticulture trade. Lastly, various evidences derived from cytological analysis, fossil pollen, guard cells comparative genomic studies indicating occurrence paleopolyploidy have been discussed.