Estimates of Genetic Variability and Trait Association among Maize (Zea mays L.) Inbred Lines

Abstract

The present study aimed to evaluate the extent of genetic variability, trait associations in 133 maize inbred lines across eleven traits. The experiment was conducted during the Kharif 2022 using a randomized complete block design (RCBD) with two replications. Analysis of variance (ANOVA) revealed significant differences among the inbred lines for all traits, indicating substantial variability. Grain yield varied from 1.89 to 10.62 t/ha with an average mean value of 3.73 t/ha. Phenotypic variance was higher as compared to genotypic variance and highest plant height followed by ear height. However, the difference between phenotypic and genotypic variance was very narrow for majority of the traits. Similarly, phenotypic coefficient of variation (PCV) was marginally higher than the genotypic coefficient of variation (GCV) for all the traits and highest GCV and PCV was recorded for grain yield per hectare (38.97%, 42.99%) followed by hundred grain weight (27.81%, 29.02%) and ear height (23.29%, 25.15%) indicating that these characters are under genetic control and have high potential for selection. High amount of broad-sense heritability coupled with high genetic advance as a percent of mean (GAM) was observed for anthesis-silking interval (0.88, 143.60%) followed by grain yield per hectare (0.82 and 72.77%) indicating that phenotypic based selection for these traits would be successful. Grain yield per hectare had the highest genotypic correlation with cob girth (0.58) followed by kernel row number (0.53), hundred grain weight (0.50), number of kernels per row (0.48) and cob length (0.43) suggesting indirect selection of these traits helps in improving the grain yield.