GENETIC COMPONENTS OF AGRONOMIC AND PHYSIOLOGICAL SEED QUALITY TRAITS IN MAIZE INBRED LINES

Abstract

The association between field evaluation and seed quality traits and their genetic components are important factors to improve germplasm characterization in a plant-breeding program. The objectives were to analyze the relationship among the mean values and combining ability effects, and to explore the genetic control of agronomic and physiological quality of seed traits. The genetic material consisted of six maize inbred lines and their single crosses among them. Data recorded were male flowering days, plant and ear height, and grain yield; seed physiological quality was obtained as the germination percentage, first count of the standard germination test, speed germination index and emergence percentage. Results indicated a wide variation (P≤0.01) among genotypes on all the evaluated traits. Significant differences (P≤0.01) were shown for most traits except grain yield on both general and specific combining ability effects. The single crosses 43x10, 4x7, 43x4 and 36x7 were identified as having high yielding, high plant and ear height, with an inconsistent association with the different physiological quality attributes. Parents 10, 36 and 43 showed good quality indices, were late, and had low plant and ear height, including grain yield. Phenotypic expression and genetic effects, supported by a correlation analysis indicate that there is not a direct and significant relationship between the agronomic and seed quality traits. These results showed that additive genetic effects were more important for ear and plant height, and for all seed quality traits, whereas the non-additive effects determined the expression of days to flowering and grain yield.