New alleles of maturity genes that influence soybean phenology.

Soybean [Glycinemax (L.) Merr.] is a photoperiod‐sensitive legume native to Asia and a major global commodity crop. Adapting flowering time to match production environments can help maximize yield potential by extending the reproductive phase while optimizing the vegetative phase length. One major flowering gene, E1, and its two homologues, E1‐like‐A (E1LA) and E1‐like‐B (E1LB), have functionally characterized alleles, but use in breeding programs is limited to mainly e1‐as for earlier flowering in northern latitudes (>36° N). Two new native alleles, e1:T110A and e1lb:S34R, are presented and characterized for their impact on days to flowering and maturity under maturity group III environments. Significant differences were observed between genotypes, and environment played a role in the lines under study. Lines with an e1‐as background had the highest number of days in reproductive phase over our two environments; a line with allele e1lb:S34R (e1‐as and E1LA) was inconsistent between years but had the longest reproductive phase in one environment. Overall, compared to soybean germplasm with functional E1, E1LA, and E1LB, lines with allele e1:T110A (E1LA and E1LB) were similar for days to flowering but matured, on average, 7 days earlier. Lines with previously characterized allele e1la:K82E (functional E1 and E1LB) had similar days to flowering and maturity as the new e1:T110A (E1LA and E1LB). The line with e1lb:S34R flowered and matured earlier than lines with functional E1LB (e1‐as and E1LA). These new alleles highlight the natural diversity that could be utilized to produce cultivars well suited for a local environment. Core Ideas: Alleles of soybean genes E1, E1LA, and E1LB can finetune flowering and maturity.Mutant allele e1:T110A shortened maturity but not flowering time compared to functional E1.Mutant allele e1lb:S34R had intermediate effects compared to functional E1LB and null e1lb alleles. Plain Language Summary: To maximize yield potential, soybean plants need to produce vegetative mass that is appropriate to support the development of as many pods and seeds as possible during the frost‐free growing season. Soybean vegetative and reproductive development is highly influenced by signals derived from day length. Relatively few differences in a small set of maturity genes have been utilized to control soybean development. From a survey of wild soybeans, we discovered new versions of two maturity genes, bred them into a soybean cultivar, and determined their effects on vegetative and reproductive development. The results showed significant effects on maturity but not flowering time for one gene and both maturity and flowering time for the other gene. The impact of this work is new knowledge about finetuning soybean adaptation to different production environments and soybean germplasm that can be exploited to potentially increase soybean yield in certain environments. [ABSTRACT FROM AUTHOR]