418 Bradfield Hall,Cornell University,Ithaca, NY 14853,USAMini-biographySusan McCouch is a Professor of Plant Breeding and Genetics at Cornell University. She received her PhD from Cornell in 1990 and spent 5 years with the International Rice Research Institute (IRRI) in the Philippines before joining the Cornell faculty in 1995. Her work focuses on rice and includes publication of the first molecular map of the rice genome in 1988, early QTL studies on disease resistance, drought tolerance, maturity and yield, development of thousands of SSR markers now widely used in rice genetics and breeding, and most recently, cloning of several genes underlying traits of importance in rice improvement. She has trained scores of young scientists in the use of molecular maps and markers for germplasm enhancement, gene discovery and evolutionary studies in rice. Her current work focuses on the identification and characterization of genes and quantitative trait loci (QTL) from low-yielding wild and exotic Oryza species that enhance the performance of modern rice cultivars. She was recently elected a fellow of the AAAS and has received prestigious teaching and faculty awards.
Discovery and utilisation of wild alleles for crop improvementSusan R. McCouch
Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
srm4@cornell.eduA narrow genetic base in modern crop varieties makes them more susceptible to disease epidemics and to environmental fluctuations. A low level of genetic variation also reduces the possibilities for sustained genetic improvement by plant breeders. Abundant genetic variation can be found in wild and exotic germplasm that is not inherently productive in modern agricultural environments. These materials provide an opportunity for breeders to expand the cultivated gene pool in combination with efficient, gene-based approaches to selection. We have used molecular maps and markers to identify quantitative trait loci (QTL) in interspecific populations derived from crosses between elite, high-yielding
Oryza sativa rice cultivars and its low-yielding wild ancestor,
O. rufipogon. These studies have shown that phenotypically inferior, wild ancestors harbour genes that can contribute positively to rice improvement. Once identified, the genes underlying the QTLs can be cloned. This holds important implications for utilising naturally occurring genetic variation to amplify the genetic base of many of our cultivated varieties and contribute positively to sustainable crop production, particularly in drought and other stress-prone environments. The isolation and characterisation of the genes underlying these QTLs provide essential information about the structure, function and evolution of the target genes. As we consider new approaches to genetic manipulation of crop plants, knowledge about the range of naturally existing variation at key loci and the impact of that variation on phenotypic performance provides a valuable roadmap for the conservation and utilisation of exotic germplasm.
