TY - JOUR AU - Fehr, W. R. AU - Ortiz, L. B. PY - 1975/07/01 Y2 - 2024/03/29 TI - Recurrent Selection for Yield in Soybeans JF - The Journal of Agriculture of the University of Puerto Rico JA - JAUPR VL - 59 IS - 3 SE - Articles DO - 10.46429/jaupr.v59i3.10611 UR - https://revistas.upr.edu/index.php/jaupr/article/view/10611 SP - 222-232 AB - Procedures have been developed for yield testing of soybeans (<em>Glycine max</em> (L.) Merr.) that permit S<sub>1</sub> testing with 1 year per cycle and S<sub>4</sub> testing with 2 years per cycle. The principal factors in the program include efficient procedures for obtaining crossed seed by hand pollination, crossing and generation advance in Puerto Rico, and yield tests in Iowa by use of hill plots. Details for each of the three factors are discussed. With the facilities available, expected genetic gain per year for yield was calculated for S<sub>1</sub> testing without male sterility (S<sub>1</sub>), S<sub>1</sub> testing with male sterility S<sub>1</sub>(<sub>ST</sub>), S<sub>4 </sub>testing without male sterility (S<sub>4</sub>), and half-sib family selection with male sterility (HF). The greatest expected gain per year was obtained with S<sub>1</sub> testing. There is more genetic variability among S<sub>4</sub> lines than among S<sub>1</sub> lines due to inbreeding, but expected genetic gain is less for S<sub>4</sub> testing because 2 years are required per cycle. S<sub>1</sub>(<sub>ST</sub>) had less expected gain per year than S<sub>1</sub> or S<sub>4</sub> testing because 2 years are required per cycle if homozygous male-fertile genotypes are evaluated. Expected genetic gain was least for HF because less genetic variability is expressed among lines than for the other three methods. ER -