Agronomic and chemical description of open-pollinated varieties of opaque-2 and purple maize (Zea mays L.) adapted to semiarid region of Argentina

Abstract

The objective of this study was to compare the evolution of two populations of opaque-2 and purple maize in the central semiarid region of Argentina, and to characterize the agronomic traits and grain chemical attributes to conclude the varietal description of each population. Introduced germplasm of both varietal types was grown under rainfed conditions during four crop years (2011/12, 2013/14, 2014/15 and 2015/16) and characterized both agronomically and chemically. Significant differences were observed between varietal types in the morphological traits of plants and cobs, but did not differ in male flowering or female flowering. Purple maize exhibited taller plants with thicker stems and smaller cobs with heavier grains than opaque-2 maize. Purple maize showed lower grain yields (mean of 4.84 vs. 6.16 tn ha−1 in opaque-2 maize) with more marked variations between cycles (3.02 to 6.62 vs. 5.47 to 7.28 tn ha−1 in opaque-2 maize). The effects of the environment and genotype x environment interaction (G × E) were more notable for grain yield and grain chemical features such us protein, amylose and phenolic compound contents. Nonetheless, most of the agronomic traits in each varietal type showed higher genetic effects (67–92% in opaque-2 maize and 55–82% in purple maize) and a lower G × E (3–14% in opaque-2 maize and 7–19% in purple maize). The advances of this study represent substantial efforts on the development, characterization and description of maize genetic resources in Argentina, which represent potential raw materials for the functional-foods industry.