Understanding meiosis and the implications for crop improvement.

Abstract

Over the past 50 years, the understanding of meiosis has aged like a fine bottle of wine: the complexity is developing but the wine itself is still young. While emphasis in the plant kingdom has been placed on the model diploids Arabidopsis (Arabidopsis thaliana L.) and rice (Orzya sativa L.), our research has mainly focussed on the polyploid, bread wheat (Triticum aestivum L.). Bread wheat is an important food source for nearly two-thirds of the world's population. While creating new varieties can be achieved using existing or advanced breeding lines, we would also like to introduce beneficial traits from wild related species. However, expanding the use of non-adapted and wild germplasm in cereal breeding programs will depend on the ability to manipulate the cellular process of meiosis. Three important and tightly-regulated events that occur during early meiosis are chromosome pairing, synapsis and recombination. Which key genes control these events in meiosis (and how they do so) remains to be completely answered, particularly in crops such as wheat. Although the majority of published findings are from model organisms including yeast (Saccharomyces cerevisiae) and the nematode Caenorhabditis elegans, information from the plant kingdom has continued to grow in the past decade at a steady rate. It is with this new knowledge that we ask how meiosis will contribute to the future of cereal breeding. Indeed, how has it already shaped cereal breeding as we know it today?