Análise de trilha para seleção de caracteres fenotípicos em linhagens de milho

Abstract

Productivity is a complex and resulting character of expression and association of different components. The knowledge of the relationship between agronomic traits and correlations analysis between grain yield and other characters, has been objective of study in plant breeding to selection process. However, despite inferences about understanding certain character, the correlation coefficients do not give exact relative importance of direct and indirect effects of these factors. In this context, the path analysis is presented as a viable alternative. The objective was to evaluate the relationship between the corn grain yield and secondary agronomic traits to identify, through the Path Analysis, the best characters suitable for breeding purposes in maize varieties, the main character yield in salable bags (bags 60 thousand seeds). The experiments were analyzed since the winter of 2013 until the summer of 2015 in 12 locations in Brazil. The design was randomized blocks and treatments consisted of 271 corn inbred lines. The characters were evaluated: Barren Plants; Malformed Ears; Dominated Plants; Dropped Ears; Discard; Ear Height; Failure of Graining; Moisture; Plant Height; Rotten Grains; Root Lodging; Silk balling; Shed in Boot; Shell Weight; Popped Kernels; Saleable Seeds Units; Total Damaged Plants; Thousand Kernels Weight; Plant Uniformity; Viviparity and Yield. The characters: Yield, Thousand Kernels Weight, Discard and Rotten Grains were the most significant for the variable Salable Seed Units. Yield is the character most suitable for indirect selection as it is the variable with the greatest direct effect, on favorable direction, to the response variable.