Detection and Molecular Characterization of Two Potyvirus Species on Cucurbits from Northwestern of Iran

Cucurbit crops belonging to the family Cucurbitaceae are one the most important horticultural crops worldwide and cultivated widely in Iran. To aim detection and phylogenetic analysis of potyvirus members, during ۲۰۱۵-۲۰۱۶, ۲۱۵ leaf samples from cucumber, melon, watermelon, and squash symptomatic with deforming and reduction in leaf size, blistering, mild and severe mosaic, fruit deformation, and stunting were collected from ۱۰ major cucurbits-growing locations in West Azerbaijan province. Following mechanical inoculation of Cucurbita pepo as an indicator plant with symptomatic cucurbit crop extracts, a variety of symptoms developed on the plants. Then, total RNA extracted from ۷۰ symptomatic leaf samples, and partial RNA-dependent RNA polymerase (NIb) (۳۵۰ bp) was amplified using universal primer pairs (NIb۲F/NIb۳R) by reverse transcription-polymerase chain reaction (RT-PCR). The infection by potyviruses in ۳۸.۷۵% of the samples was confirmed based on the result. The five PCR products belonging to different hosts at the expected size (۳۵۰bp) were sequenced. One sample (Ir-Na: MH۴۹۱۹۷۹) was determined to be infected by the Watermelon mosaic virus (WMV) whereas four samples (Ir-Ma:MH۴۹۱۹۷۹, Ir-Ng:MH۴۹۱۹۸۰, Ir-Pi:MH۴۹۱۹۸۱, and Ir-Ur:MH۴۹۱۹۸۲) infected by Zucchini yellow mosaic virus (ZYMV). In the phylogenetic analysis based on Maximum-likelihood, three ZYMV isolates (Ir-Ng, Ir-Pi, and Ir-Ur) were placed in subgroup I whereas one isolate (Ir-Ma) was placed in subgroup II belonging to group A. Also, WMV isolate (Ir- Na) was placed in CL phylogroup.

Keywords:

Detection , Universal primer , WMV , ZYMV