9527725 Mitchell-Olds Hybrid vigor is central to many questions in agriculture and genetics. Increased fitness of heterozygotes (the phenomenon of hybrid vigor or heterosis) contributes to high yield in many crop species, and may maintain genetic variation in wild populations. Despite their importance, the factors influencing hybrid vigor and other forms of genetic variation are poorly understood at the genetic and molecular level. The research proposed takes a reductionist genetic approach to this problem by studying causes of quantitative genetic variation in important physiological traits. Chromosomal locations and DNA sequence variation of genes that may control metabolism will be examined in an effort to understand the factors influencing levels of genetic variation, vigor, and fitness or yield in plant populations. This work may have important benefits in agriculture, forestry, and understanding of natural populations.
