Reproductive Systems and Dynamic Management of Genetic Resources

Abstract

My approach to the above topic will be based on Dobzhansky’s well-known dictum that “nothing in biology makes sense except in the light of evolution.” My thesis is that genetic resource conservation, as well as the deployment of genetic resources in plant breeding, are evolutionary processes and that understanding of the evolutionary mechanisms responsible for the genetic progress that has occurred over time will provide the most certain guide to future progress. I turn now to empirical data to examine the genetic changes that have occurred in three species groups in response to many generations of natural and man-guided selection for high performance in agricultural environments. These species groups are: cultivated barley and its conspecific wild ancestor Hordeum vulgare, ssp. spontaneum; corn, Zea mays and its wild ancestor teosinte (Zea species); and the tetraploid slender wild oat, Avena barbata and its diploid ancestor, the A. birtula-A. wiestii complex. The Hordeum and Avena species groups are heavily self-pollinated whereas the Zeas are outcrossers.