MORPHOLOGICAL TRAITS TO ASSESS DIVERSITY AMONG MAIZE POPULATIONS IN A REGION: CHALQUEÑO LANDRACE CASE

Abstract

Studies on genetic diversity of maize (Zea mays L.) in a given region are considered convenient for a better utilization of such diversity, and considering that for these kind of studies a series of characters has been suggested as appropriate, it is important to determine if the list of those variables gotten from among maize races comparisons, should be modified for diversity characterization of populations within a particular ecological region. With this purpose 104 maize accessions were characterized, quantifying 59 morphological traits in four environments; most of the accessions are form the eastern region of the state of Mexico (Chalco-Amecameca-Juchitepec), México. Data were analyzed using the estimation of the variance components ratio r_c =[σ c² / (σ_a² + σ_ca²)], as well as the single value descomposition of the correlation matrix, mainly to determine which original traits were responsible for the three first principal components. This allowed to identify II morphological characters that could be suggested as minimal to carry on studies on regional maize genetic diversity: days to silk, ear height, cob percentage in the ear, number of branches in the tassel, mid-ear diameter kernel length, kernel volume, kernel width, number of rows in the ear, kernel width/length, and kernel color. Therefore, the productive female structures seem to be the most important morphological criteria to be used for diversity classification between and within maize races.