Unlocking Genetic Mysteries: Genome Mapping in Polyploids

Introduction

Polyploids are organisms with more than two sets of chromosomes. They are very important in agriculture and play a fundamental role in evolutionary processes, such as differentiation of species (Soltiset al., 2016). One of the most fundamental descriptions of any organism is its ploidy level and chromosome number. Plant scientists in particular will be familiar with this representation of the chromosomal constitution of the sporophyte generation (i.e. the adult plant). The second term in this seemingly simple equation describes the normal complement of chromosomal copies possessed by a member of that species, which is generally 2x (“two times”) for diploids. Species where this number exceeds two are collectively referred to as polyploids. Not unexpectedly, each polyploid individual is the product of the fusion of gametes from two parents, just like their diploid counterparts. In other words, polyploids can also be defined as individuals derived from non-haploid gametes (in the case of triploids derived from diploid × tetraploid crosses, only one gamete satisfies this condition).