Mapping genes for flowering time and frost tolerance in cereals using precise genetic stocks

The development of comprehensive genetic maps based on molecular markers has increased the power of genetical analysis immensely in the last few years. Characters previously recalcitrant to analysis, such as abiotic stress responses, are now amenable, and individual major genes and QTL mediating the variation can be identified. This has allowed the development of strategies for stress amelioration by adjusting the timing of the life cycle and introducing genes which enable the plant to tolerate stress. These strategies are illustrated here by showing how genes for vernalization response and cold tolerance on chromosomes 5A and 5D of wheat have been identified and located. Additionally, their relationships to genes in other species, such as barley and rice can be characterised through comparative mapping approaches, leading to strategies for their isolation using rice genomic tools.