SUPERIOR POPULATIONS WITHIN THE MAIZE DIVERSITY FROM EASTERN STATE OF MÉXICO

Abstract

Within the corn (Zea mays L.) types available in a region, there are differences in morphology and yield capacity. The present study evaluated native maize populations based on their morphology and yield, to identify outstanding collections and to compare yields from populations collected in 1968-1972 and 1995-1996. In the localities of Poxtla, Tlapala and Tecámac, 130 collections were evaluated, most of them native from the eastern region of the State of México and some hybrids as controls. In all of them, 18 morphological characters were measured. Analyses of variance by location and combined through environments were performed, as well as orthogonal contrast analysis to compare populations collected in 1968-1972 vs. 1995-1996. Comparison of harmonic means (n) was done with the Tukey test. Prominent collections in the creamy Chalqueño group were COL-6712, COL-6758, COL-6715, COL-6717 and COL-260v, since their grain yield was similar to that of the best hybrids; for Elotes Chalqueños group the best entry was COL-6719, and for the Cacahuacintle and Ancho groups COL-6718 and COL-6739 were the best collections. Based on percentage of grain, ear diameter, width, length and volume of grain and weight of 100 seeds, it was detected that populations collected in 1995-1996 were superior to those of 1968-1972. The empirical selection done by farmers suggests that they are able to generate local maize populations with longer growth season and greater grain yield. The facts that farmers maintain their preference for local varieties instead of sowing hybrids, and that there are superior local populations, can be used for the conservation of biological diversity and for improving corn productivity in situ.