Heterosis - An overview and its utilization in forestry

Heterosis is a widely occuring biological phenomenon in both the plants and animal species. The exploitation of heterosis is a common objective in plant breeding. In forest tree breeding this usually takes the form of strategies to avoid inbreeding depression or the exploitation of positive heterosis through deployment of high performing full sibs in either family or clonal forestry. The tailoring of tree in future biomass production by genetic manoeuvring holds a great promise. Depending upon breeding objectives, both positive and negative heterosis is useful for crop improvement. In general, positive heterosis is desired for yield and negative heterosis for early maturity. The manifestation of heterosis has enabled plant and tree breeders to significantly improve the tree performance by exploiting hybrid vigour. The many studies on quantitative genetics in forestry over the past 20 years have helped to advance breeding populations. With the availability of modern molecular tools, scientists can begin to explore the phenomenon of heterosis into its individual genetic components should provide new help to guarantor a plentiful supply of quality products for the future generations.