ABSTRACT
Barley yellow dwarf viruses [BYDVs] are members of the luteovirus group transmitted only by aphids. The five serotypes [PAV, RMV, RPV, MAV and SGV] were reported. In Egypt, BYDV is common with PAV serotype being dominant. In the current report, total RNA was purified from infected wheat leaf plants and Aphids. RT-PCR technique was used to amplify and identify the coat protein gene sequence of BYDV- PAV and RMV serotypes in wheat using specific primers designed by ABI primer express software. Expected PCR products were sequenced and aligned together with related gene bank sequences and revealed the high similarity up to 93%. RT- Real Time PCR technique was used to detect and quantify BYDV. The results indicate that the infection ratio of Giza 164 samples are higher than the infection ratio of Sids 7 based on Ct value, and virus concentration in aphids are higher than in wheat for both serotypes. In addition, the sensitivity of RT- Real Time PCR is 3 to 5 fold higher than conventional PCR for detecting virus infection