ASSOCIATION TESTING OF CANDIDATE GENES REGULATING FLOWERING TIME AND PLANT HEIGHT.

¹ Department of Genetics, North Carolina State University, Raleigh, NC 27695

² Department of Genetics, University of Wisconsin, Madison, WI 53706

³ Department of Crop Science, North Carolina State University, Raleigh, NC 27695

⁴ USDA-ARS, North Carolina State University, Raleigh, NC 27695

Animal systems have taken advantage of association approaches to rapidly link nucleotide polymorphisms with traits. A similar approach was utilized to relate candidate gene sequence diversity with the quantitative traits of flowering time and plant height in maize. A putative transcriptional regulator of floral transition, indeterminate1 (id1), is thought to be a major player in controlling flowering time (Colasanti et al, 1998). The candidate gene dwarf3 (d3) is involved in the biosynthesis of gibberellin and influences plant height and maturity (Winkler et al, 1995). Each candidate gene was PCR amplified and sequenced from 100 diverse maize lines. Flowering time and plant height for each line were scored in two environments. Estimates of population structure, derived from random markers throughout the genome, were used to eliminate non-functional associations. The effect of sequence polymorphisms on flowering time and plant height was tested with association tests. Understanding the effects of such nucleotide polymorphisms and their presence in the germplasm will improve selective breeding techniques for these quantitative traits.