Breeding plans in case of global warming

Summary

Many cultivated crop plants of temperate and cool temperate zones have during their domestication been transferred far from their original habitats and been distributed over a wide range of climates. In general crop plants seem to possess potential to climatic adaptation. Processes in the past have taken hundreds or thousands of years and over large number of generations. The concern on the velocity of the expected global warming and of subsequent changes in other factors justifies planning of breeding for global warming. Perennial plants, forest trees in particular are more at the focal point than annual plants. Most agricultural annuals may be replaced any year with another cultivar or species better adapted to contemporary circumstances. Trees need tens of years to reach commercial dimensions or fructiferous age.

Capriciousness is the main problem of climate change. Large variation of temperature, precipitation among years actually masks the gradual change of average values. The amplitude of variation among years exceeds the predicted average change. Thus, plasticity of individuals besides within population variation in adaptive traits is a corner stone of breeding plans. From the ecological point of view two factors are significant: 1. mild winters may interfere dormancy release and frost tolerance, and also alter host-parasite relationships. 2. The timing of thermal seasons will change in relation to photoperiod. This phenomenon is most prominent in the far north, where the relative warming is largest and the photoperiodic pattern steepest. Even though perennial plants display potential of acclimatization, selection and breeding are eligible measures to improve productivity. As long as the magnitude and velocity of the global warming remain uncertain, it is impossible to set specified aims to breeding. The only reasonable method is to run parallelly several lines with differing patterns of adaptive traits. Multiple population breeding system (MPBS) seems to be tailored to this purpose.