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Colchicine induced polyploids have notdirectly contributed for crop improvementin the past. On the other hand, theso-called natural polyploids, derived fromthe functioning of numerically unreduced(2n) gametes have been shown to bemore relevant for crop improvement in manycases. Different types of cytologicalabnormalities during meiosis can give riseto 2n gametes and the geneticcomposition of these gametes is variable.Depending on the type meioticabnormalities, various types of 2ngametes, such as first division restitution(FDR), second division restitution (SDR),indeterminate meiotic restitution (IMR) andpost meiotic restitution (PMR) gametes,among others, have been described in recentyears. For the improvement ofautopolyploids such as potato, alfalfa,Vaccinium spp., and some of thefodder grasses, FDR gametes have beenproved to be highly useful. However, theuse of 2n gametes for the …