Control genético y modulación ambiental de los componentes del rendimiento de híbridos de maíz (zea mays l.) liberados en diferentes décadas

INCOGNITO, SALVADOR JUAN PABLO; MADDONNI, GUSTAVO ÁNGEL; LÓPEZ, CÉSAR GABRIEL

Rosario

Congreso; Congreso Nacional de Maíz 2014; 2014

AIANBA

Breeding has increased tolerance to crowding of modern hybrids, which attain higher grain yields (GY) than the older genotypes. Few research of genetic gain in maize crops, took into account the eco-physiological traits related to grain yield and the trade-off between kernel number (KN) and kernel weight (KW). No information exists of phenotypic plasticity (Pf) of these traits. The objectives of this study were to determine breeding effects on GY, KN and KW, and the eco-physiological traits related to GY components. Modulation of the environment on these traits was also analyzed using their Pf. Four argentine hybrids representatives of the 70´, 90´, 00´and 10´ decades were sowing at three plant densities (4-8-12 pl m-2) during 2012-2013 in the experimental field of FA-UBA. Measurements of both GY and KN per plant were recorded in ten plants per plot, together with KW, plant grow rate during the critical period (PGRCP), and source:sink ratio during the the post-silking period (S:SPS). The higher GY of modern hybrids was determined by higher KN and larger KW. Most traits showed the capacity of capture favorable, intermediate and unfavorable environmental conditions but the most modern hybrids showed higher stability (lower Pf) not only for GY but also for most evaluated traits mainly at high plant density.