1a.Objectives (from AD-416):
Analyze seed contents of protein, oil and ions as a function of position on the mainstem and Determine whether changes in free hormone concentrations are responsible for differences in internode length among soybean genotypes.
1b.Approach (from AD-416):
Intermodes from diverse genotypes will be collected and analyzed for major hormones (abscisic acid, auxin, gibberellins and brassinosteroids), and results will be correlated with internode length and plant height. Plants will be harvested at maturity and mainstems will be divided into quadrants. Seeds will be analyzed for protein and oil contents using near-infrared spectroscopy and ionomic analysis will be done using inductively-coupled plasma spectroscopy. Plant hormones will be analyzed by liquid chromatography coupled with mass spectrometry.
Cultivar differences in plant height at maturity and seedling root to shoot ratio were observed but internode length was not correlated with any hormone measurements made in preliminary experiments. Canopy architecture was also not correlated with seed composition (protein and oil concentration) or the position effect on seed composition. Ionome analyses of seeds and vegetative plant parts are currently being analyzed.