Identification of tolerance to high density and lodging in short petiolate germplasm M657 and the effect of density on yield-related phenotypes of soybean

Abstract

Soybean yield has traditionally been increased through high planting density, but investigating plant height and petiole traits to select for compact architecture, lodging resistance, and high yield varieties is an underexplored option for further improving yield. We compared the relationships between yield-related traits, lodging resistance, and petiole-associated phenotypes in the short petiole germplasm M657 with three control accessions during 2017–2018 in four locations in the Huang–Huai region, China. The results showed that M657 exhibited stable and high tolerance to high planting density and resistance to lodging, especially at the highest density (8×105 plants ha−1). The regression analysis indicated that a shorter petiole length was significantly associated with increased lodging resistance. The yield analysis showed that M657 achieved higher yields under higher densities, especially in the northern part of the Huang–Huai region. Among the varieties, there were markedly different responses to intra- and inter-row spacing designs with respect to both lodging and yield that were related to location and density. Lodging was positively correlated with planting density, plant height, petiole length, and number of effective branches, but negatively correlated with stem diameter, seed number per plant, and seed weight per plant. The yield of soybean was increased by appropriately increasing the planting density on the basis of the current soybean varieties in the Huang–Huai region. This study provides a valuable new germplasm resource for the introgression of compact architecture traits that are amenable to providing a high yield in high density planting systems, and it establishes a high-yield model of soybean in the Huang–Huai region.