Characterization of a new Apple dimple fruit viroid variant that causes yellow dimple fruit formation in ‘Fuji’ apple trees

Abstract

A 303-nucleotide viroid was isolated from an apple tree (Malus 9 domestica, 'Fuji') cultivated in Japan. The viroid had 84.9% overall nucleotide sequence homology to Apple dimple fruit viroid (ADFVd), a member of Pospiviroidae, reported from Italy. This viroid differed from the Italian variant by 47 mutations (38 substitutions, six deletions and three insertions), and most of these mutations occurred on either side of the central conserved region. The leaves and branches of the infected trees did not have any disease symptoms, but the fruits were dimpled and yellow. The infected scions were top-grafted onto a healthy 'Fuji' apple tree, which tested positive for this viroid in a northern hybridization analysis, and yellow dimple fruits were produced in the second growing season. We propose that this viroid is a new variant of ADFVd and causes yellow dimple fruit formation in 'Fuji' apple trees.

On the early identification and characterization of pear blister canker viroid, apple dimple fruit viroid, peach latent mosaic viroid and chrysanthemum chlorotic mottle viroid

“…ADFVd has been reported in apple trees in Italy (Di Serio et al, 1996), Lebanon (Choueiri et al, 2007), Japan (He et al, 2010), and China (Ye et al, 2013). A study on the virome of fig trees performed by high-throughput sequencing (HTS) approach allowed the identification of ADFVd in a fig accession in Italy (Chiumenti et al, 2014).…”

Viroid Diseases in Pome and Stone Fruit Trees and Koch’s Postulates: A Critical Assessment

“…ADFVd isolates, composed of sequence variants ranging in size from 306–307 nt, have been characterized in Italy, China, Lebanon and Iran [ 62 , 63 , 64 , 65 , 66 ], while an isolate containing divergent variants of 303 nt has been reported in Japan [ 67 ]. Phylogenetic analyses of the ADFVd variants have shown that they cluster according to their geographic origin [ 68 ].…”

First report of Apple dimple fruit viroid in apple trees in Iran

“…Total RNA was extracted from leaf and bark of shoots using an RNeasy Plant Mini Kit (Qiagen, Germany) and preparations were subjected to RT‐PCR with the apscaviroid‐specific PCR primers, PBCV100C and PBCV194H which amplify the central conserved region of viroids in this genus (He et al , 2010). Synthesis of cDNA was done using a RevertAid First Strand cDNA Synthesis Kit (ThermoScientific, USA).…”

“…Red Delicious showing dappling, crinkling and irregular yellow spots on their fruits. The samples were collected from two orchards in the area of Maragheh, northwest Iran and viroid-like symptoms were observed in approximately 5% of the trees in the surveyed orchards.Total RNA was extracted from leaf and bark of shoots using an RNeasy Plant Mini Kit (Qiagen, Germany) and preparations were subjected to RT-PCR with the apscaviroid-specific PCR primers, PBCV100C and PBCV194H which amplify the central conserved region of viroids in this genus (He et al, 2010). Synthesis of cDNA was done using a RevertAid First Strand cDNA Synthesis Kit (ThermoScientific, USA).…”