Method for Early Generation Soybean Population Selection Using F2 High‐Parent Heterosis Testing

Abstract

The germplasm pool for North American soybean [Glycine max (L.) Merr.] is narrow, and identifying novel and useful genetic diversity is time consuming and expensive. The objective of this research was to develop an early‐generation population screening method to select diversity × elite populations. The F2 high‐parent heterosis (F2 heterosis) was used as a tool to identify populations with the greatest potential for producing high‐yielding lines in subsequent generations. For Set 1 populations, six populations were selected for significantly positive F2 heterosis, and six were selected for significantly negative F2 heterosis. When these populations were advanced into plant row yield trials, five out of six populations with positive F2 heterosis had the highest average yield for the top 5% of the lines, and five out of six populations with negative F2 heterosis had the lowest average yield for the top 5% of the lines. For Set 2, two populations with the highest positive F2 heterosis value had significantly higher average population yield and average top 5% selection yield compared with two populations with negative F2 heterosis. Differences in combining ability were evident in both sets of populations, as two populations with one parent in common may have opposite classifications for F2 heterosis. Using F2 heterosis as an early‐generation population selection tool may enable the focus of resources to identify which populations have the best opportunity to develop high‐yielding lines with unique diversity. These data will need to be verified in replicated yield testing over multiple years and locations.