Supplementary Material 1: Table S1. Paralogous gene pairs in segmental duplication events of alfalfa MsBBX genes. Table S2. Collinear genes of MsBBXs between alfalfa and Arabidopsis, alfalfa and O. sativa, alfalfa and M. truncatula. Table S3. The functions of Cis-regulatory elements in MsBBX gene promoters. Table S4. The primers used in this stud