Variability, Association and Selection of Promising Characters for Breeding Creole Maize

Abstract

Genetic variability is the main characteristic when seeking to select promising genotypes for plant breeding. Thus, the objective of this work was to investigate the genetic variability in agronomic and morphological characteristics of traditional varieties of maize, in addition to determining the degree of association and the selection of variety and promising characters to be explored in programs of genetic breeding of Creole maize. The experiment was conducted at the Federal University of Acre (UFAC), Rio Branco - Acre, in the 2017/2018 harvest period. A randomized block design was used, with five replications. The treatments were four varieties of Creole maize (V1, V2, V3 and V4) from the Vale do Juruá region and another hybrid cultivar LG 3040 (HI). The morpho-agronomic characteristics were evaluated in the useful area of the plots: days to silking (DS), days to anthesis (DA), plant height (PH) and height ear insertion (HEI), stem diameter (SD), mass of ear (ME), length ear (LE), diameter ear (DE), total grain mass (TGM), mass of 100 grain (M100G), grain moisture (GM) and grain productivity (GP). The data were subjected to analysis of variance and comparison of means. The values of genotypic and phenotypic variance were also estimated, heritability in the broad sense, selection accuracy, phenotypic, genotypic and environmental correlation, in addition to the principal component analysis (PCA). Variations in characteristics were found between the varieties of Creole maize and their interrelations, showing greater influence of ME, PH, TGM, M100G, DE and GP in the expression of the phenotype. Therefore, it is concluded that there is genetic variability in the characteristics evaluated, with emphasis to V4 that showed superior performance allowing direct selection of the characteristics SD, ME, TGM and M100G to be incorporated into an breeding program.

Variabilidade nutricional e física de variedades tradicionais de milho (Zea mays L.) cultivados no vale do Juruá, Acre, Brasil

“…A importância do milho no Brasil é ampla, pois sua produção ocorre tanto em pequenas propriedades tipicamente familiares, cuja finalidade é a subsistência, bem como em grandes extensões de terra, na qual predomina o uso de tecnologias de produção e mão-deobra qualificada (3) . Nas regiões desenvolvidas economicamente, as lavouras são destinadas ao cultivo do milho híbrido e transgênico, enquanto nas regiões onde há predominância da agricultura familiar, os milhos cultivados constituem-se das variedades tradicionais locais (4) .…”