Colchicine-Induced Polyploidy in Leguminous Crops Enhances Morpho-Physiological Characteristics for Drought Stress Tolerance

Legumes play a significant role in the alleviation of food insecurity, maintaining soil fertility and achieving sustainable crop production under adverse environmental conditions. The increased demand in legume production contemplates that attention on the genetic improvement of these crops through various means such as genetic engineering and mutation breeding should take a centre stage in global agriculture. Therefore, this paper provides succinct analysis of currently available literature on morphological and physiological traits in polyploidised leguminous plants to counter the adverse effects of drought stress. The effects of colchicine on various morphological and physiological traits of polyploidised legumes compared to their diploid counterparts were examined. Numerous reports revealed variations in these traits such as improved root and shoot growth, plant biomass, chloroplastidic content, protein, RNA and DNA. The differences observed were also associated with the strong relationship between plant ploidy-induction and colchicine application. Furthermore, the analysis indicated that polyploidisation remains dose-dependent, and may be achievable at a shorter space of time as this antimitotic chemical interferes with chromosome separations in somatic plant cells. The efficiency of this process also depends on the advancement of treatment conditions (in vitro, in vivo or ex vitro) and successful regeneration of polyploidised plants for adaptation under drought stress conditions. As such, the improvement in metabolite profile and other essential growth characteristics serves as a clear indication that induced polyploidy needs to be further explored to confer resilience to environmental stress, and improve crop yield under drought stress conditions in leguminous plants.