Identification of a zucchini yellow mosaic virus infecting squash in Hangzhou

Abstract

A filamentous virus was isolated from naturally infected squash (Cucuribita moschata L.), showing yellow mosaic in Hangzhou, Zhejiang Province, in autumn 1999. This virus was found to cause systemic symptoms on all the Cucuribitaceae plants tested. It was identified as zucchini yellow mosaic virus (ZYMV) by host reaction tests, morphological characteristics observations and tissue alteration tests. The 3' end sequence, containing the coat protein (CP) gene and the 3' untranslated region of this virus, was obtained by RT-PCR and sequenced. Sequence alignment of CP genes was carried out in compare with three American ZYMV isolates, including the Conneticut isolate, Florida isolate and California isolate, and Tonga isolate of Watermelon mosaic virus 2 (WMV2). ZYMV HZ00s1 had 93%-94% homology of nucleotide sequence with other three documented ZYMV isolates, whereas its sequence similarity to WMV2 Tonga isolate was found to be as low as 67%. Meanwhile, sequence similarity between the three America ZYMV isolates was 95% to 99%. Homology of deduced amino acid sequence of CP between HZ00s1 and three other ZYMV isolates was 95%-98%. Our results proved the occurrence of ZYMV as a principal pathogenic virus on Cucuribitaceae crops in South part of China.

Keywords

• ZYMV
• virus identification
• 3' end sequence
• coat protein
• similarity comparison