YIELD AND THEIR COMPONENTS IN MAIZE-TEOSINTE BACKCROSSES

Abstract

Maize breeders preffer traditional sources of germplasm instead of taking advantage of teosinte (Zea spp) populations which can incresse genetic variability in their breeding programs. One of the problems in using wild relatives species is that their economical yield is too low, because they have not had the same selection process than those crop species. Nevertheless, to appraise the utility of teosinte populations in the maize breeding programs constitutes a challenge. The objetive in this study was to evaluate in six elite modified maize lines, the changes in economic yield and their components in function of teosinte population and backcrossing levels used. Lines were evaluated at Celaya, Gto. (1996 and 1997) and Tlajomulco, Jal. (1996). The experimental design was a randomized complete block with three replications under a split-split-plot arrangement. The six lines were included as main plots. The six races of teosinte were considered in the subplots and the four backcrosses were in the sub-subplots. Results showed that the modified lines with teosinte germplasm could be used in the formation of populations for a recurrent selection program with broad genetic variability to combine the modified lines in BC₂ and BC₃ to combine the total diversity of the lines and the teosinte sources. If it is required to recover the lines for hybridization programs, it should be in BC₃ with the teosinte source that have favorable alelles for grain yield and less unfavorable alelles for other agronomic traits.