COMPARISON OF 3 SELECTION PROCEDURES FOR DEVELOPMENT OF EARLY-MATURING SOYBEAN LINES

Northern-latitude soybean [Glycine max (L.) Merr.] breeders are interested in breeding procedures that will efficiently extract high-yielding Maturity Group (MG) 0 and MG I genotypes from crosses involving MG II and III parents. The objective of this research was to compare the efficiency of three selection procedures: pedigree, single-seed descent, and single-seed descent with early-maturity selection for extraction of MG 0 and I genotypes. Four populations derived from crosses of parents of MG 00 and 0 with parents of MG II and III were used to evaluate the selection procedures. Twenty-seven F5 lines of MG I or earlier were selected for each procedure in each population and were evaluated for yield, maturity, plant height, lodging, seed weight, and lengths of the reproductive (R1-R7) and seed filling (R4-R7) periods. No consistent yield advantages were evident for any breeding procedure when the mean yield of all lines, or the top three yielding lines from each maturity set were compared. In addition, no consistent differences were apparent among the selection procedures for maturity, height, lodging, seed weight, or lengths of the R1-R7 and R4-R7 periods. Because it required the least resources, the SSDE procedure emerged as the most cost-effective procedure.