Testcross response to four cycles of half-sib and S2 recurrent selection in the BS13 maize (Zea mays L.) population

Abstract

Inbred progeny recurrent selection has been shown to be theoretically superior to several forms of noninbred-progeny recurrent selection. However, recent improvements to theory and empirical evidence suggest that inbredprogeny recurrent selection is not a superior method of recurrent selection. In the BS13(S) population, inbred-progeny recurrent selection has not been effective at improving population per se performance. However, no other selection programs have been evaluated in BS13(S), so there is no basis to compare inbred-progeny recurrent selection in BS13(S) to other methods to determine if other methods might be more effective. Four cycles of half-sib selection with inbred line B97 as tester have been completed. The first four cycles of half-sib selection and first four cycles of inbred-progeny selection were testcrossed to B97 and evaluated in a replicated experiment in 2007 and 2008. Half-sib selection improved grain yield, grain moisture, stalk lodging, root lodging, test weight, and final plant density, whereas inbred-progeny selection did not improve any of these traits. This study adds to growing empirical literature suggesting that inbred-progeny recurrent selection is inferior to noninbred-progeny selection methods. A hypothesis has been put forth that pseudo-overdominance caused by linkage disequilibrium may have limited response to inbred-progeny recurrent selection in BS13(S) as well as other maize populations. © Crop Science Society of America.