Synthetic polyploidy in spice crops: A review

Abstract

Spice crops comprise diverse, economically valuable crops with numerous applications ranging from culinary to pharmaceutical industries. Spices are an integral part of cuisines worldwide, imparting characteristic flavor, aroma, and pungency to food. Breeding and crop improvement efforts in spices have focused on enhancing yield and quality parameters (essential oil, oleoresin, fiber, etc.) along with bioactive chemical constituents. The prominent breeding strategies followed are selection, hybridization, mutation, in vitro approaches, and transgenics. Polyploidy is one of the drivers of speciation and evolution, increasing the biological diversity in many crops, including spices. Polyploidy, either through natural means or artificial induction, broadens the scope of crop improvement. The artificial induction of polyploidy is usually done via antimitotic chemicals, duplicating the complete chromosomal set and allowing for genetic alterations and rearrangements that result in phenotypic changes across the board. As a result, increasing ploidy in crops often results in improved yield, biomass, vigor, biotic and abiotic stress tolerance, and secondary metabolite production, all of which can contribute to the economic success of these crops. This review provides an overview of research on artificial polyploidization in spice crops, including the polyploidy induction system, polyploidy generation, and screening methods to select the polyploids of interest. Thus, we have summarized the significant applications of artificial polyploidy in crop improvement that can serve as a potent reference for future research works in the same direction in the under-explored spice crops.