ADAPTATION OF ELITE TEMPERATE AND TROPICAL MAIZE POPULATIONS TO NORTH DAKOTA

Plant breeders often introduce new genetic materials to their breeding programs, but have the challenge of local adaptation. These materials, even if they are elite, need a period of adaptation and testing before they can be fully incorporated into a breeding program. Also, there is a general concern regarding the genetic diversity of maize available to grow on farms, especially in short-season environments where hybrid offer is reduced. Therefore, in order to maintain the sustainability of maize and thus prevent genetic vulnerability, new genetic materials need to be incorporated into North Dakota (ND) germplasm to increase genetic diversity available on northern U.S. farms. Future genetic gains depend on useful genetic diversity. The objective of this study was to assess the adaptation of late-maturing elite temperate and tropical maize populations to ND environmental conditions. BSK(HI)C11, BS11(FR)C13, NDBS1011(FR-M)C0 (a cross between BS11(FR)C13 and BS10(FR)C13), and ND-SHLC (a composite of four highland Mexican populations) were adapted by stratified mass selection for days to silking. The sample size utilized per population was 22,500 plants and the earliest 400 plants to produce silks were selected. Cycle populations were evaluated for direct and indirect responses to selection in a randomized complete block design (RCBD) across nine ND environments. Results showed stratified mass selection to be a cost/effective breeding procedure to adapt elite populations. All improved populations were, on average, a week earlier in days to silking often associated with better grain yield performance and agronomic performance after three to four cycles of selection. Mass selection for adaptation was successful across all maize populations independent from genetic background and/or origin.