Diallel Analysis and Correlation Between Agronomic Traits of Tropical Maize Progenies Under Two Nitrogen Levels.

DIALLEL ANALYSIS AND CORRELATION BETWEEN AGRONOMIC TRAITS OF TROPICAL MAIZE PROGENIES UNDER TWO NITROGEN LEVELS

Rafael Parreira Diniz; Renato Barbosa Camargos; Fernando Lisboa ; Guedes; Márcio Lisboa Guedes; Kaio Olímpio das Graças Dias; Joao Candido de Souza

Nitrogen use efficiency of plants is an active area of study in agricultural research. This is because reduction in the input of nitrogen fertilizers in the production systems can lead to reductions in costs and reduction of environmental problems while creating more sustainable farming system. This research aimed to study the genetic control, characterize progenies S_0:2 regarding the nitrogen use efficiency and to verify, through correlations and relationships of cause and effect, whether there are differences between agronomic traits of maize plants grown in environments with low and high availability of nitrogen in the soil. Four progenies previously classified as responsiveness and tolerance to nitrogen were crossed in complete diallel scheme, obtaining the F₁'s hybrids and reciprocals crosses. The progenies, the hybrids and four controls were set up in two experiments with different nitrogen availability in the soil, low and high, in a randomized complete block design with three replications. The characteristics evaluated were: the leaves chlorophyll content, male and female flowering, stem diameter, plant height, first ear height, plant healthy, stay-green, prolificacy and grain yield, and yield components traits. Analyzes of variance were performed for each experiment, and the joint analysis was subsequently performed. The diallel analysis for grain yield was carried out by using the Griffing’s method 1, besides the estimation of correlations and direct and indirect effects through path analysis. The non-additives effects were more important and stable for the nitrogen use efficiency when assessing grain yield. The classification of hybrid progenies was not stable when it advanced a generation of self-pollination. The phenotypic correlation of leaves chlorophyll content and grain yield was significant only in high-N environment. The female flowering for low-N environment presented a direct effect on grain yield.

Keywords: Zea mays L. Diallel analysis. Additive and non-additive effects. Phenotypic correlation. Path analysis.