The development and use of a molecular model for soybean maturity groups

Authors: Langewisch, Tiffany; LENIS, JULIAN - Dow Agrosciences; JIANG, GUO-LIANG - Virginia State University; WANG, DECHUN - Michigan State University; PANTALONE, VINCENT - University Of Tennessee; Bilyeu, Kristin

Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2017
Publication Date: 5/30/2017
Publication URL: http://handle.nal.usda.gov/10113/5729139
Citation: Langewisch, T.L., Lenis, J., Jiang, G., Wang, D., Pantalone, V.R., Bilyeu, K.D. 2017. The development and use of a molecular model for soybean maturity groups. Biomed Central (BMC) Plant Biology. 17:91. doi: 10.1186/s12870-017-1040-4.

Interpretive Summary: Soybean has been adapted to grow in particular regions defined by latitude. In the United States (US), these regions have been categorized into different bands of soybean maturity groups (MGs). Soybean lines are classified into a MG based on the days it takes the line to go from planting to when 95% of the pods can be harvested (full maturity). Soybeans must be grown in the region that fits their MG so that the farmer can obtain optimal growth and yield. This specificity to geographical location hinders the ability of plant breeders to efficiently and broadly deploy agriculturally important traits across different environments and maintain the appropriate maturity. Maturity is influenced by both environmental factors and the contribution of maturity genes commonly referred to as E maturity genes that control plant development. In this report we investigated the frequency of variation and diversity of the E maturity genes in a large collection of soybean land-races, North American ancestors, Chinese cultivars, North American cultivars, commercial lines, and private-company lines. We determined the E gene combinations needed to adapt soybean to different MGs in the US and discovered a strong footprint of breeding selection for E gene combinations released in the US. This data allowed us to formulate a three gene maturity model that will enable plant breeders to more effectively transfer traits into different MGs and to increase the overall efficiency of targeted breeding for specific MGs.

Technical Abstract: Achieving appropriate maturity in a target environment is essential to maximizing crop yield potential. In soybean [Glycine max (L.) Merr.], the time to maturity is largely dependent on developmental response to dark periods. Once the critical photoperiod is reached, flowering is initiated and reproductive development proceeds. Therefore, soybean adaptation has been attributed to genetic changes and natural or artificial selection to optimize plant development in specific, narrow latitudinal ranges. In the United States (US), these regions have been classified into 10 maturity groups (MG), with lower MG being shorter season than higher MG. Growing soybean lines not adapted to a particular environment typically results in poor growth and significant yield reductions. The objective of this study was to develop a molecular model for soybean maturity based on the alleles underlying the major maturity loci: E1, E2, and E3. We examined allelic variation and diversity of the E maturity genes in a large collection of landraces, North American ancestors, Chinese cultivars, North American cultivars or expired Plant Variety Protection lines, and private-company lines. The E gene status of accessions in the USDA Soybean Germplasm Collection with SoySNP50K Beadchip data was also predicted. We determined the E allelic combinations needed to adapt soybean to different MGs in the US and discovered a strong signal of selection for E genotypes released in the US. The E gene maturity model proposed will enable plant breeders to more effectively transfer traits into different MGs and increase the overall efficiency of targeted breeding for specific MGs.