Evaluation of Maize Inbred Lines for Iranian maize mosaic virus (IMMV) Resistance

Abstract

In present study, the putative resistance capacity of thirty five maize inbred lines against Iranian maize mosaic virus (IMMV) was studied. Reaction to IMMV was analyzed under natural field infection and controlled conditions in a greenhouse in 2010 and 2011. In the greenhouse experiments, the maize plants were inoculated at two-leaf stage using the planthopper Laodelphax striatellus. In the field trials, an early sowing cultivation was used to facilitate a higher infection rate. The responses of inbreds to IMMV were assessed by symptom development and ELISA. The rate of natural infection of IMMV in susceptible control (SC704) was about 20%. MO17 showed about 40% infection in the first year. Both field and greenhouse results confirmed that MO17 was more susceptible to IMMV than SC704 and more reliable to be used as susceptible control in future studies of IMMV. Sowing one row of SC704 as vector spreader between every 5 rows of inbred lines caused sufficient vector propagation and virus transmission. Results of both field and greenhouse experiments showed little and no IMMV infection on K1263/1 and K3547/5, respectively. Hence, they were considered as IMMV-resistant. These lines with CIMMYT origin can also be used for production of resistant hybrids. Results showed that resistance to IMMV was not associated with maize maturity because resistance and susceptibility were found in both early and late matured inbred lines. Disease incidence and ELISA values were strongly correlated. Reduced plant height, ear weight and ear diameter and length and delayed silking were observed in plants infected with IMMV.