1a. Objectives (from AD-416):
1) Increase oil content above 22% while maintaining protein content and yield; and 2) to explore new and beneficial genetic sources of oil traits that are environmentally stable.
1b. Approach (from AD-416):
We will do detailed comparisons of pod temperatures (10 cultivars) during seed development using a thermocouple (slower and requires contact with pod) and IR thermogun (faster and does not require physical contact). If differences are confirmed again in 2011, we will consider possible physiological mechanisms (e.g., transpirational cooling) and physical factors (e.g., pubescence, color). We will also screen 180 selected accessions from the USDA Soybean Germplasm Collection for oil content at the top and bottom of the canopy. Accessions that have high overall oil content and a strong canopy position effect, will be identified in the summer of year 1 and during the winter, crosses will be made with genotypes that have a small canopy position effect (low delOIL). The progeny of these crosses will be examined in the summer of year 2 for bulk oil content and canopy position effects.
3. Progress Report:
This new project began in April; we will screen diverse genotypes for bulk seed composition and canopy position effects on protein, oil and mineral nutrient concentration. The possible contribution of variation in seed fill duration will be explored. In addition, the possible functional significance of pod stomata will be assessed by monitoring pod temperatures and the response to exogenous abscisic acid application. Finally, effects of row orientation (East-West versus North-South) will be evaluated to see if small differences in yield and composition are reproducible.