Evaluation of yield relationships and yield components in maize hybrids using multivariate and graphical methods in Karaj region

Selection of desirable hybrids compared to other maize hybrids (Zea mays L.) is one of the methods used to achieve high grain yield in maize. Also, the most important morphological features affecting grain yield can be used in the selection and introduction of genotypes.

This study was conducted to investigate the relationship between different traits with grain yield and the selection of the most important morphological characteristics affecting the grain yield of corn hybrids for genotype selection. The experiment was conducted as a randomized complete block design (RCBD) with three replications in the research farm of Islamic Azad University, Karaj Branch in the cropping years of 2018-2019 on 12 commercial single cross corn hybrids.

The results of combined analysis of variance showed that the genotypes had a significant difference in the probability level of 0.01 in terms of agronomic traits. The effect of  year × genotype was also significant in ear length, grain width, grain length, grain thickness, 1000-grain weight and grain yield. Based on the results of Duncan method comparison, KSC704 and KSC707 genotypes were selected as the highest ranked hybrids. In comparison with the mean of genotype × year in terms of grain yield, SC302 hybrid and KSC701 and KSC706 hybrids in the second crop year were identified as top-ranked genotypes. Factor analysis by Verimex method introduced four factors that explained 73% of the variance of the data and were named as grain characteristics, ear characteristics, plant height and ear length. The results of correlation analysis between traits also showed a positive and significant correlation between ear length trait with number of rows per ear and grain yield. Also, the number of rows per ear had a positive and significant correlation with grain width and grain length. Graphic analysis based on polygonal view of KSC707, KSC706, KSC260, KSC705 and SC604 genotypes were more superior to other hybrids studied. In the genotype ranking chart, KSC707 hybrid was identified as the ideal genotype, which was more favorable than other genotypes in terms of studied traits. The correlation diagram between the traits showed a positive and significant correlation of most of the traits with the yield trait, based on which the traits of grain width, 1000-grain weight, grain length, ear length, number of rows per ear and grain yield had a positive and significant correlation. They were together. Based on the grouping diagram of genotypes according to the studied traits, genotypes were grouped into four parts.

In general, KSC707 genotype was identified as the optimal genotype in terms of the studied traits. The results of this study, which was evaluated in two cropping years, indicate that these genotypes can be used in breeding programs to increase yield.