COMPARISON OF YIELD AND MORPHOLOGICAL CHANGES IN V-520C TUXPEÑO MAIZE ADAPTED TO HIGHLANDS IN MEXICO

Abstract

Visual mass selection (VMS) is an effective method to adapt tropical and subtropical races of maize (Zea mays L.) to other environments. The Tuxpeño V-520C maize variety is native to the lowlands of Veracruz, but was adapted to highlands through VMS for 14 (C14) and 19 (C19) cycles by selecting healthy and good yielding plants. This study evaluated grain yield and morphological changes in plant and ear at the original variety V-520C (C0), C14 and C19, along with Compuesto Universal (CU) of the Chalqueño race as a control. In the 2013 and 2014 agricultural cycles, six experiments were carried out in the states of Mexico and Veracruz. A randomized complete blocks design with three replications was used. Grain yield, agronomic traits, tassel characteristics and yield components were recorded. The combined analysis of variance across localities and the individual one for Veracruz did not include CU while analysis for the highlands did. There were significant morphological changes due to VSM in the combined and highland analyses. There was significance between environments, between genotypes or in the genotype-by-environment interaction for grain yield and morphological traits of plant and ear in all the three analyses. C19 increased favorable gene frequencies for higher yield in the combined analysis (3.5 t ha^-1) and in that of Veracruz (2.6 t ha^-1); also, it reduced days to flowering, plant height and tassel size, and increased the number of primary branches of the tassel and yield components. Because of this, C19 was the best genotype, similar to CU. Visual mass selection was effective for adaptation of Tuxpeño V-520C maize from the tropical zone to the temperate zone.