Response to eight cycles of full-sib reciprocal recurrent selection for grain yield and standability in BS10 and BS11 maize populations

Abstract

Developing heterotlc patterns is important in applied maize breeding programs. Interpopulation recurrent selection can be helpful for developing new heterotic patterns and enhancing those identified previously. The objective of this research was to estimate the direct and indirect responses to eight cycles of full-sib reciprocal recurrent selection in maize populations BSIO and BSll. The populations themselves and their crosses corresponding to cycles 0, 2, 4, 6, and 8 were evaluated at two levels of inbreeding (F=0 and F-0.5). Testcrossed populations to the respective cycle 0 populations, and unrelated inbred lines were included in the evaluations. The experiments were conducted in eight environments. Eight cycles of selection were effective for increasing grain yield for the population cross (7.5%) as well as for BSIO (2.9%) and BSll (1.6%). Standability, prolificacy, and other important agronomic traits also changed in the desired direction. In most instances the responses were linear over cycles of selection. The selected populations also performed better than the unselected populations in crosses with testers, other than the opposite population. Changes in inbreeding depression and heterosis were associated with selection. FSRRS seems to