A Method to Differentiate and Improve Corn Germplasm for Seed Emergence Under Stress.

The sensitivity of warm season crops to cold, saturated conditions during seed emergence is a major limitation to productivity and yield. Corn seeds are commonly exposed to sub-optimal soil temperatures and water logging conditions as a result of increasing adoption of early planting and minimum tillage among other factors. These conditions commonly lead to reduced stands and uneven emergence. Developing corn hybrids with improved seed emergence under stress is a main goal for corn breeders but this is limited by availability of predictive, high throughput phenotypic assays for germplasm differentiation. In this study we evaluated ultra-drying of corn seed as a method to differentiate hybrids for ability to emergence under saturated cold conditions in the field. We also evaluated a cold soak germination test for ability to predict field emergence under stress and facilitate high throughput screening for this trait. Results of field emergence of ultra-dried and control seed under stressful and optimal field conditions will be presented. We will also present germination results of ultra-dried and control seeds in the cold soak test as well as standard cold and warm germination tests, and discuss the application of these methods in breeding programs.