Biological and molecular characterization of two Zucchini yellow mosaic virus isolates from Syria

Abstract

Zucchini yellow mosaic virus (ZYMV) is the most prevalent virus in cucurbits in Syria. Two Syrian ZYMV isolates, SYZY‐1 and SYZY‐3, collected from a courgette field in 2006 were characterized using molecular and biological means for the first time. These isolates showed biological diversity with regard to their pathogenicity and symptoms. SYZY‐1 was more aggressive in cucurbits, but could not induce any infection in Fabaceae. On the contrary, SYZY‐3 could not infect cucumber and melon plants, induced milder symptoms in courgette and watermelon but induced local and occasional systemic infection in Fabaceae tested. Nonetheless, according to their molecular characteristics, SYZY‐1 and SYZY‐3 were closely related. The SYZY‐1 CP nucleotide and amino acid sequences had similarity of 99.5% and 100% with those of SYZY‐3, respectively. The high similarity of the CP nucleotide sequences of SYZY‐1 and SYZY‐3 with that of a ZYMV isolate from Germany suggests a common origin. Adaptation to different hosts might have caused the variable biological properties of these Syrian ZYMV isolates.