Root distribution contributing to pushing resistance in soybean

Abstract

To efficiently develop soybean (Glycine max) cultivars resistant to root lodging, which occurs in the late growth stages and causes significant yield losses, it is essential to understand the root traits that contribute to this resistance. However, the root zones most responsible for plant support remain unidentified, leaving uncertainty about which should be prioritized in root trait evaluation. This study aimed to identify root distributions associated with pushing resistance, which is closely related to root lodging, through vertical and horizontal root pruning combined with analyses of root distribution during the full pod to full seed stages. The results suggest that root length (≥0.5 mm diameter) within the top 15 cm of the soil and within 20 cm horizontally from the plant, especially directly beneath the plant, plays a crucial role in maintaining pushing resistance. The root zone identified in this study may provide a useful target for the de‍tailed evaluation of root traits in field-grown soybean during the late growth stages, and approaches such as shov‍elomics and the basket method could facilitate such evaluations in future breeding programs.