Molecular characterization of barley yellow dwarf virus coat protein gene in wheat and aphids

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

Detection and partial sequence identification of grapevine leafroll-associated virus-1 in Egypt

Grapevine leafroll-associated virus 1 [GLRaV-1] was detected in the grapevine plants collected from different cultivated areas in Egypt and tested using different serological and molecular tools. Double-antibody sandwich ELISA [DAS-ELISA] was successfully carried out using GLRaV-1 polyclonal antibodies to detect infected plants. PCR with primers designed at the heat shock protein 70 [HSP70] gene region, a fragment of 271 bp of GLRaV-1, was used. Molecular hybridization with non-radioactive probes was used to detect the presence of virus particles. The partial sequence of HSP70 fragment from the Egyptian isolate of GLRaV-1 was performed and showed high identity [95%] with the Australian isolate of GLRaV-1 sequence. The molecular methods used for viral diagnosis showed a higher sensitivity in the detection of GLRaV-1 compared to DAS-ELISA. These procedures may serve as an alternative method for GLRaV-1 detection, due to the weak sensitivity of ELISA test to differentiate between the different isolates