PHENOTYPIC DIVERSITY AMONG MAIZE POPULATIONS WITH DIFFERENT DEGREES OF PIGMENTATION

Abstract

Kernel color is one of the components of maize (Zea mays L.) phenotypic diversity. In order to explore variation on such a trait and agronomic performance, 114 maize populations native of several states of the Mexican Central Plateau, were characterized for kernel color based on visual perception, and preclassified into five groups. Five experiments under randomized complete blocks design were established, at Montecillo, state of México in 2003, one per kernel color, in order to prevent pollen interference. Three ears per plot were sampled and kernel color was recorded in two ways: quantitatively by using a colorimeter (lightness, chroma, and hue), and qualitatively by visual classification from the lightest to the darkest. Besides, information on ear, cob, and kernel dimentions and weight were recorded, as well as days to tasseling and silking. Multivariate analyses on four color parameters allowed classification of the 114 maize populations into 6 groups: white (28 populations), yellow (44), orange (4), red (15), blue (18), and purple (5). There were significant differences (P ≤ 0.05) among color groups for traits such as days to tasseling and silking, number of rows on ear, kernel length and width, and ear and cob diameter. On the other hand, ear length, kernels per row, and grain weight per ear were similar among color groups. Populations with colored kernels were earlier and with greater kernel size, along with narrower cob and greater ear diameter, than noncolored kernels.