Evaluation of the Genetic of Resistance to Maize Iranian mosaic virus (MIMV) by Generations Mean Analysis

This study was conducted during 2011-2014 at the College of Agriculture, Shiraz University and Research Center for Agriculture and Natural Resources of Fars Province. A cross between MO17 and K1263/1 was conducted as susceptible and resistant lines against MIMV. Following the production of F1 and F2 populations, BC1 (F1 × MO17) and BC2 (F1 × K1263/1) generations were produced by backcrossing of F1 with either parental lines. Evaluation of different generations was performed by inoculation of plants by Laodelphax striatellus in greenhouse and field trials in two years. Traits related to MIMV resistance were measured as area under disease progress curve (AUPDC), the percentage of chlorotic disease symptoms, and absorbance value of samples at 405 nm in ELISA test. Based on the results, the highest and lowest amounts of neasured trails were scored in parental lines MO17 and K1263, respectively. Results of GMA and scaling tests indicated that 3-parameters model including mean (m), additive [d] and dominance [h] effects had the best fitness in both experiments. In genetic model, m, [d] and [h] were significant for all traits. Not-significant epistatic effects indicated the lack of inter-genic interactions in inheritance of traits in segregating populations derived from parental lines. Dominance ratio close to unit (1) confirmed complete or partial dominance gene action in genetic control of traits. Heritability of traits was higher that 90%. Therefore, production of resistant inbred lines via selection methods for benefaction of additive effects of resistance genes and dominance effects in production of resistant hybrids would be useful in breeding programs of resistance to MIMV.