First Report of Peach latent mosaic viroid in Peach Trees in Montenegro.

Abstract

Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd) are known to infect stone fruit species worldwide. The viroid infection can be latent or induce a variety of disease symptoms. Stone fruit samples were collected in Montenegro for a Plum pox virus (PPV) survey in 2007. Thirteen samples infected with PPV, taken from 12-year-old peach trees (Prunus persica (L.) Batsch, cv. Elegant Lady) in the area of Cemovsko field, were tested for the presence of PLMVd and HSVd by reverse transcription (RT)-PCR. Mild or severe mosaic, chlorotic rings, and fruit deformations were observed on some trees. Total RNA was extracted from all samples with a RNeasy Plant Mini Kit (Qiagen, Chatsworth, CA) and RT-PCR was performed. Samples were tested for HSVd and PLMVd infection using primer pairs RF-43/RF-44 for PLMVd (1) and VP-19/VP-20 for HSVd (2). Amplification products of approximately 348 bp were obtained from nine samples with PLMVd primers. Amplification products from seven samples were successfully cloned into pGEM-T Easy Vector (Promega, Madison, WI) and used for transformation of Escherichia coli. At least four clones of each sample were sequenced. Obtained sequences were 337 and 338 nucleotides long and shared 90.3 to 100% identity. Consensus sequences of each sample were deposited in GenBank under Accession Nos. JF927892-JF927898. They showed 92.6 to 97.9% identity among each other, 94 to 98% identity with the PLMVd isolate G sequence (Accession No. EF591868) and 91.8 to 94.4% identity with PLMVd sequence M83545. HSVd was not detected in analyzed samples. PLMVd infections were found on peach trees in an area where approximately 40% of the peach production is located. Therefore, PLMVd infections can pose a threat to peach production in Montenegro. To our knowledge this is the first report of PLMVd infection of peach in Montenegro.