Genetic analysis of low-n traits in maize (<i>Zea mays L</i>) using triple test cross

Abstract

Low-N maize variety is developed for its ability to tolerate low nitrogen soil environment. This experiment was conducted to study the genetic implication of Low-N maize variety for grain yield and related traits under low nitrogen soil conditions triple test cross analysis. Inbred lines used for the study were generated from twelve low nitrogen tolerance open pollinated maize varieties after six generations of selfing. Two inbred lines along with their F1 were used as testers for ten inbred lines in a triple test cross pattern to generate 30 crosses. The 30 crosses, their parents and the testers to State University, Ado-Ekiti during 2017 planting season. The experimental design was a Randomized Complete Block Design (RCBD). Data were collected on plant height, ear height, days to 50% anthesis, days to 50% silking, incidence of curvularia leaf spot, blight, plant aspect, ear aspect, ear rot, stay green, cob per plant, ear weight, grain moisture content and grain yield. All data were subjected to analysis of variance and complete genetic estimates. Additive and dominants were significant (P < 0.05) for all traits; however, epitasis estimates were not significant for all the traits tested. The degree of dominance component indicated partial dominance for all the traits. Correlation coefficients for days to 50% anthesis and 50% silking, plant height, ear height, number of cobs per plant and grain yield were positive and significant (P < 0.05). Since both additive and dominance gene actions were important for low-N traits, the use of reciprocal recurrent selection procedure can be adopted in incorporating the trait into elite maize varieties.