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It has been commonly accepted that soybean domestication originated in East Asia. Although East Asia has the historical merit in soybean production, the USA has become the top soybean producer in the world since 1950s. Following that, Brazil and Argentina have been the major soybean producers since 1970s and 1990s, respectively. China has once been the exporter of soybean to Japan before 1990s, yet she became a net soybean importer as Japan and the Republic of Korea do. Furthermore, the soybean yield per unit area in East Asia has stagnated during the past decade. To improve soybean production and enhance food security in these East Asian countries, much investment has been made, especially in the breeding of better performing soybean germplasms. As a result, China, Japan, and the Republic of Korea have become three important centers for soybean genomic research. With new technologies, the rate and precision of the identification of important genomic loci associated with desired traits from germplasm collections or mutants have increased significantly. Genome editing on soybean is also becoming more established. The year 2019 marked a new era for crop genome editing in the commercialization of the first genome-edited plant product, which is a high-oleic-acid soybean oil. In this review, we have summarized the latest developments in soybean breeding technologies and the remarkable progress in soybean breeding-related research in China, Japan, and the Republic of Korea. [ABSTRACT FROM AUTHOR]

The maturity group (MG) system is widely used to group soybean [Glycine max (L.) Merr.] varieties based on their growth periods and photothermal responses. However, there is still no universal standard or quantifiable methodology for MG classification. In this study, phenological traits of 107 Chinese, 4 Far East Russian representative soybean varieties, and 113 North American reference varieties covering 13 MGs were evaluated at eight locations (ranging from 30 to 50° N) in four ecoregions of China for two consecutive years (2014 and 2015). Relative maturity groups (RMGs) were attributed to all the varieties based on the linear regression models. To decimalize the RMG values of the early‐maturing varieties belonging to MGs below 0, negative values were defined for MGs 00, 000, and 0000. The additive main effects and multiplicative interaction (AMMI) model was used to screen 185 standard candidate varieties for MGs 0000 to VIII. This study provided a systematic and quantifiable methodology for RMG identification in soybeans. The methodology is expected to be widely adopted by soybean regionalization and germplasm exchanges throughout the world and will be helpful for characterizing the photothermal sensitivity and adaptability of the given soybean varieties. [ABSTRACT FROM AUTHOR]