A genetic study of agronomic traits of corn inbred lines using a diallel graphic analysis

In 2007, seven inbred lines of corn were crossed based on a complete diallel cross design. The parents and 42 subsequent hybrids were planted at the research field of Seed and Plant Improvement Research Institute in Karaj using a randomized complete block design with three replications. Yield and other agronomic traits were measured. Hayman method was used for data analysis. The results indicated over dominance gene effects for anthesis-silking interval, days from silking to physiological maturity, plant height, ear length, hundred grain weight, seed depth, number of kernels per row and grain yield. Gene effects for days to physiological maturity, ear leaf area, stamen leaf area and number of rows per ear were partial dominance. The broad
sense heritability ranged between 10.7% and 93.1% for 100-grain weight and number of rows per ear and narrow sense heritabilities were estimated between 1% and 85% for grain yield and number of rows per ear, respectively. Nonadditive genetic effects were predominant to control of all traits except days to physiological maturity, ear leaf area, stamen leaf area and number of rows per ear. The parents which had the highest number of dominant and recessive genes for different traits were: in respects of anthesis-silking interval, lines, No. 6 and 5, days to physiological maturity lines, No. 7 and 3, days from silking to physiological maturity lines, No. 2 and 3, plant height lines, No. 6 and, ear leaf area, lines No. 1 and 4 were selected. For stamen leaf area, lines No. 4 and 2, ear length and number of kernels per row lines, No. 3 and 2, 100-grain weight and number of rows per ear, lines No. 3 and 5, grain depth, lines No. 6 and 4 and grain yield, lines No. 5 and 2 could be selected for further breeding programs.