Polyploidization using colchicine in horticultural plants: A review

Polyploidization of plants occurs in nature but it is a slow and gradual process that has driven evolution and speciation throughout the ages. As time is important, polyploidization can be induced in a shorter period by using colchicine that interferes with mitosis of cells. To develop an efficient polyploidization protocol of a species, up to date research is paramount. The efficiency of polyploidization induction system depends on the advancement of propagation techniques of the species which consist of in vitro, ex vitro and in vivo systems. During polyploidization induction, several parameters can be manipulated to obtain highest percentage of polyploids. These parameters include colchicine concentration, treatment duration and explant type. Several other factors that enhance these parameters include usage of shaker, DMSO (Dimethyl sulfoxide) and medium types. Induced putative polyploids are selected indirectly based on morphological parameters, anatomical parameters and flow cytometry. Selected putative polyploid can be verified directly and accurately using chromosome counting. Polyploidization has been practised for decades with notable breakthrough recently in terms of polyploidization system and polyploid identification. Current trend in polyploidization has included polyploid characterization in their protocol in terms of polyploid ultrastructure, bioactive compounds, photosynthetic capabilities and metabolomics studies. Establishment of methodologies in polyploid characterization will help the plant breeder to assess noble phenotype among polyploids which can be beneficial for commercial purpose. This paper seeks to provide an overview on an array of current best practices in polyploidization using colchicine.