Improvement of soybean yield and lodging in relation to morphological traits

Future yield gains may depend on an understanding of the past changes made to soybean by breeding. The objectives of this study were: (1) to use experiments in Ohio and Liaoning province to compare a set of older cultivars from Liaoning province with modern counterparts from breeding programmes in Liaoning and Ohio, and (2) to use elite Ohio lines to assess the potential for improvement in yield and lodging resistance through related morphological traits. Modern Ohio cultivars, modern Liaoning cultivars, and old Liaoning cultivars were differentially adapted to environments. Both Chinese and USA breeders have selected successfully for improved yield, shorter plants, shorter internode length, greater lodging resistance, and higher harvest index. However, there was no significant variation among elite Ohio lines for harvest index. Lodging resistance of late elite lines would be improved by selection for fewer nodes; that of early lines by selection for short internode length.