Archivio Journal of Plant Pathology

Abstract:

Prunus necrotic ringspot virus (PNRSV, Genus Ilarvirus, Family Bromoviridae) is pollen and seed transmitted and this contributes to its spread in stone-fruit trees. In 2015, 18 leaf samples from nectarine (Prunus persica var. nucipersica) symptomatic trees were collected from East-Azerbaijan and Zanjan provinces in west and north-west of Iran. Trees showed stunting, and exhibited chlorotic rings, mosaic and necrotic ringspots on leaves. When total RNAs were subjected to reverse transcription polymerase chain reaction (RT-PCR) with a pair of primers (Ilar1 and Ilar2) (Moury et al., 2000), an expected DNA fragment of about 206 bp was amplified from 6 of the 10 tested samples. The indicator plant Cucumis sativus developed systemic mosaic, chlorosis, stunting, and leaf deformation after the cotyledons were inoculated with PNRSV isolates, as previously described (Rakhshandehroo et al., 2006). Furthermore, total RNAs extracted from six Ilarvirus-infected samples were used to amplify the complete coat protein gene by RT-PCR, using VP81 (5- AGTGGATCCATGGTTTGCCGAATTTGC-3) and VP103 (5-ACATAAGCTTCTAGATC TCAAGCAGGT C-3) primer pair (Aparicio et al., 2003). Comparing the new sequences in the GenBank showed a high similarity (98%) between new PNRSV isolates and isolates from Iran (rose; KJ599817), Poland (rose; DQ003584) and India (almond; AM408909). Phylogenetic tree generated by MEGA6 program in Neighbor joining (NJ) method confirmed that these new PNRSV isolates (accession Nos. KX353930-KX353935) were grouped within a cluster formed by PNRSV-subgroup II isolates from Iran, Poland, Chile and USA. To the best of our knowledge this is the first report of PNRSV on nectarine from Iran.