Hybridization

Abstract

Hybridization involves crossing of two different genotypes that results in a third individual with a different set of traits. Crossing the same species is easy that produces fertile progeny. Because of chromosome-pairing problems during meiosis, wide crosses are difficult and produce sterile progeny. Hybridization is through either insects (oil palm) or wind (maize) under natural conditions. Such plants are referred to as cross-pollinated species. In plants with perfect flowers (autogamous, having flowers with both stamens and pistils), cross-pollination rarely occurs in plants (like wheat and rice) since they are normally self-pollinated. Plants that have separate pistillate and staminate flowers on the same plant (such as maize) are monoecious. Plants that have male and female flowers on separate plants (such as asparagus) are dioecious. Through artificial means, hybrids of both cross-pollinated and self-pollinated plants can be accomplished. The breeder must know the time of development of reproductive structures of the species, treatments to promote and synchronize flowering and pollinating techniques. The concept of hybrid vigour, or heterosis, has resulted from hybridization.