Identification of Molecular Markers and Candidate Genes Associated with Time to Flowering and Length of Reproductive Period in Soybean Through Association Mapping

Adaptation to temporal stress can be achieved by modifying flowering time and lengthening the reproductive period. To identify genotypes, molecular markers, and genes related with these traits, a set of 94 soybeans were genotyped using 7125 SNPs and 6465 DArTs. The genotypes were grouped according to their duration cycle (cycle) and were analyzed, days from emergence to beginning bloom (E–R1), days from beginning bloom to beginning pod (R1–R3), and days from beginning pod to full seed (R3–R6), identifying fifty-six genotypes with short E–R1 (Sh.E–R1) and/or prolonged R1–R3 and R3–R6 (L.R1–R3 and L.R3–R6). The population structure determined with 14 SSR markers that best adjusted was K = 2. For a total of 203 markers associated with Sh.E–R1, L.R1–R3, and L.R3–R6, 1221 candidate genes were identified, of which 17 were previously cited and/or containing markers located in their sequence and were selected for future studies. Splitting the reproductive period in two phases allowed the detection of variability through it. It was verified the existence of genotypes with early bloom and/or prolonged reproductive period within germplasm with similar cycle. The genotypes identified, molecular markers, and associated genes can be used in breeding programs to extend the reproductive period in soybean.