3-MODE ANALYSES OF MAIZE USING MORPHOLOGICAL AND AGRONOMIC ATTRIBUTESMEASURED IN MULTILOCATIONAL TRIALS

This study provides examples of the application of three-mode methods to agronomic and morphological data from multiattribute and multilocat ional trials of accessions from two Mexican maize (Zea mays L.) races, Conico and Tuxpeno. Initially, Conico accessions from the state of Me xico were classified into five subgroups, whereas Tuxpeno accessions w ere classified into three subgroups based on the ecogeographical regio n of origin. A three-mode classification method reassigned accessions to form more homogeneous subgroups. The new Conico groups were called C1, C2, C3, C4, and C5 and the new Tuxpeno groups were named T1, T2, a nd T3. Intra-racial genetic diversity was investigated by three-mode p rincipal component analysis. Most Conico Group C3 accessions had low g rain yield, early maturity, short plants, and short ears. Group C2 acc essions had the tallest plants, the shortest kernels, and the narrowes t ears; whereas, Group C4 accessions had the longest kernels and the w idest ears. Accessions in Groups C1 and C5 were the highest yielders a nd had the longest ears. A core subset would include accessions from a ll five subgroups with an approximate average response for all attribu tes, plus some accessions with extreme responses. Tuxpeno Group T2 acc essions were earlier and had shorter plants than the accessions from G roup T1. Group T3 accessions had higher grain yield and longer kernel length. A core subset of Tuxpeno accessions could be formed as suggest ed for Conico. If a Tuxpeno core subset with high grain yield and shor ter plant type is desired, more accessions from Groups T2 and T3 shoul d be included.