Grain composition variation among native maize (Zea mays L.) of Yucatan, Mexico

The diversity of races and native populations of maize (Zea mays L.) has great food, social and economic importance for rural communities in Mexico, and should to be studied for documentation, conservation and utilization. The aim of this study was to evaluate the variation in protein, lysine, tryptophan, crude fiber, ash, oil and starch of grain in a collection of 41 native populations of maize from the north-central region of Yucatan, Mexico, of the populations known locally as Nal t'eel, Xmejen nal, T'síit bakal and Xnuuk nal. The materials were increased in Iguala, Guerrero, in the autumn-winter 2002-2003 cycles. The experimental design was randomized block with two replications per treatment; an ANOVA was carried out and treatments means were compared with Tukey's test. There were significant differences (p≤0.05) in protein content (9.35 to 12.50 %), lysine (0.27 to 0.39 %), tryptophan (0.08 to 0.13 %), ash (1.12 to 1.83 %), oil (3.37 to 4.52 %), crude fiber (0.72 to 1.65 %) and starch (57.54 to 69.92 %). Besides, the variation patterns are associated with populations: early Nal t'eel and Xmejen nal had the highest contents of protein and tryptophan and late T'síit bakal and Xnuuk nal had lower contents of protein and higher contents of lysine. Six populations of Xmejen nal, one of Xnuuk nal and one of Nal t'eel were outstanding. Also, positive and significant correlation (p?0.05) was observed between ash and lysine (0.99) and tryptophan (0.97) content in the Nal t'eel group. The results showed high variability in grain composition, useful for breeding programs of native maize materials and to formulate strategies of in situ conservation of local collections in the study region.