Recurrent Selfed Progeny Selection for Yield in Soybean Using Genetic Male Sterility

Abstract

The value of recurrent S1 line selection using genetic male sterility to achieve intercrosses has been questioned because of reduced seed set on male‐sterile S1 progenies, which can affect the precision of yield measurements. Recurrent S1 progeny selection for yield was practiced in two soybean [Glycine max (L.) Merr.] populations (designated II and III) that segregate for genetic male sterility. Recombination of selected lines was accomplished through insect pollination, and yield evaluations of S1 families disregarded the occurrence of male‐sterile plants in the plots. This study determined (i) rates of progress from four cycles of selection on seed yield in both populations and (ii) effects of selection for yield on other agronomic traits. Yield of Population II increased 76.6 ± 23.8 kg ha‒1 cycle‒1 (b ± SE), for a 2.1% yr‒1 increase; plant height increased 5.9% and lodging decreased 8.9% over the four cycles. Selection in Population III did not produce a significant (P > 0.05) linear increase in seed yield (only 37.7 ± 55.7 kg ha‒1 cycle‒1) and there were no significant (P > 0.05) changes in other traits. The success of selection for yield in Population II but not in Population III was most likely due to differences in genetic variability and heritability between the two. Because yield improvement was significant in Population II, it was concluded that segregation of male sterility in the S1 families was not a serious impediment to the evaluation of their relative yield potentials. Thus, genetic male sterility proved to be a useful tool for recurrent yield selection because of the ease with which selected lines are intermated.