PROTEIN QUALITY IN MAIZE LANDRACES FROM THE MOUNTAINS OF THE STATE OF NAYARIT, MÉXICO

Abstract

Knowledge of the genetic diversity of native maize (Zea mays L.) prevailing in the mountainous region of the State of Nayarit, México, might contribute to its preservation and use. Few studies on the nutritional attributes of these maizes for the benefit of indigenous ethnic groups that own such plant genetic heritage have been carried out. In this study the nutritional attributes of 45 accessions of native maize from the mountains of Nayarit were measured. Collections were conducted from 2003 through 2006 at two physiographic units identified as: Sierra Baja and Sierra Alta. Bofito Pinto (2 accessions), Blandito, Chino Morado y Negro (accessions 57, 58, 66, 49 and 36) formed the group with the best quality protein; which had low percentage of protein (9.0 % in the whole grain and 5.4 % in endosperm, as an average). Nevertheless, the highest lysine (3.52 and 3.65 %) and tryptophan (0.55 and 0.68 % in protein) contents, were located in blue-grain maizes. Accessions 38 and 6 were outstanding for high oil content (6.0 and 5.2 %), 44, 20 and 33 accessions for high protein (12.0, 11.7 and 11.6 %), accessions 6, 44, 45, 50 and 60 provided the largest amounts of lysine and tryptophan. In accordance with the requirements reported by the FAO/WHO for the diet of infants under five, 24 collections able to provide more than 50 % of the requirements of lysine were identified, while five accessions contributed more than 50 % of the requirements of tryptophan, especially in blue grain maize accessions. Therefore, the protein quality of these native maizes is nutritionally acceptable.