Genetic Parameters Using Line × Tester Multiplication for Growth, Yield and Quality of Maize

Abstract An on-site experiment was conducted in the Anbar-Ramadi Governorate, situated at a longitude of 43.26 and a latitude of 33.43, during both the spring and fall seasons of 2022. A total of 10 lines were utilized, consisting of 3 paternal lines and 7 pure maternal lines. The crossbreeding was conducted using the strain × examiner multiplication method, resulting in the production of 21 distinct hybrids. The objective of the study was to investigate genetic action, genetic factors, and the impacts of general and particular combining susceptibility using a randomized complete block design (RCBD) with three replications. All attributes exhibited significant variations between the parents and their hybrids. The Inb23 strain demonstrated superior performance in terms of average individual plant output, achieving a weight of 138.32 g. Additionally, the Inb17 × AGR21 hybrid had the greatest average plant yield, measuring 198.28 g. The ZP607 tester had the most significant beneficial impact on plant output in terms of general combining ability, with a value of 3.097. The variation components of particular combining ability were larger than the variance components of general combining ability. The importance of dominance variance exceeded that of host variance. The heritability in the narrow sense was low for the number of grains per stalk and yield, but it achieved its maximum level. The weight of 300 seeds and the number of effective leaves were 14.27% and 13.44%, respectively. This resulted in a dominance score greater than one for all attributes. The study concludes that it is feasible to utilize certain superior parents in crossbreeding to create unique hybrids that have the capacity to combine and generate high grain yields. This is because many of their traits are governed by dominance and superdominance. Additionally, the trait of the number of effective leaves can serve as a reliable indicator for enhancing yield.