BIOLOGICAL AND MOLECULAR VARIABILITIES OF MOROCCAN PAV-TYPE ISOLATES OF BARLEY YELLOW DWARF VIRUS
B BENCHARKI1, J MUTTERER2, M EL YAMANI3, D ZAOUI4 J V ZEIGLER-GRAFF2 and G JONARD2
1Faculte des Sciences et Techniques, PO Box 577 Settat, Morocco; 2lnstitut de Biologie Moleculaire des Plantes, 12 rue General Zimmer, Strasbourg Cedex 87084, France; 3INRA de Settat- Morocco; and4 Faculte des Sciences, El Jadida, Morocco
Background and objectives
Materials and methods
Results and conclusions
In parallel, nucleic acid sequences were studied for the 12 isolates and focused on the coat protein (CP) gene using reverse transcriptase-polymerase chain reaction and sequencing. Sequence analyses showed that all the isolates were identical in size: 603 nt and 200 amino acid residues. Sequence homology grouping yielded the same clusters of the isolates as found earlier. The CP of the isolates in cluster 1 showed 98.5-100% nucleotide and 97.5-100% amino acid identity, while the CP of the isolates in cluster 2 showed 95.9-99.7% nucleotide and 97.5-99.5% amino acid identity. In contrast, the CP between the two clusters ranged from 88.1 to 91.1% nucleotide identity and 83.0 to 87.5% amino acid identity. The comparison of the CP Moroccan isolates and those already established reveals that the difference occurs in 32 amino acid residues. The CPs of cluster 1 were closely related to the Australian (Vic-PAV), North American (NY-PAV, P-PAV), and Japanese (JPN-PAV) PAV-type isolates, while the CPs of cluster 2 were closely related to the North American PAV-129 isolate. Clusters obtained on the basis of genetic variability of the CP gene correlated well with those yielded by the biological variation.