Peach red marbling and peach sooty ringspot, two new virus‐like degenerative diseases of Prunus

Abstract

More than 600 Prunus samples were examined by using a nonradioactive digoxigenin‐labelled RNA probe specific for hop stunt viroid (HSVd). Prunus salicina and Prunus armeniaca appeared to be better hosts than Prunus persica. The weak viroid concentration in flowers and young leaves of peach trees growing in the field did not permit its detection in such samples. The diagnosis was more reliable (about 85%) with bark and leaves aged 4 months and more, from regrowths of GF 305 peach seedlings inoculated and kept in the greenhouse. Detection of HSVd in leaves and bark of apricot and Japanese plum plants aged 3 months or more also proved reliable (about 80% and 90%, respectively). HSVd could be transmitted in apricot, peach and plum nucleic acid preparations to GF 305 peach seedlings by repeated stem slashing, and to cherries (Prunus avium and Prunus serrulata) by approach grafting with an infected P. salicina source. The viroid was eliminated from 18% of the clones obtained after thermotherapy. In the course of this study, 25 selected Prunus accessions suspected to be infected by unusual diseases were analysed by hybridization with a HSVd‐specific probe and by indexing on GF 305 peach seedlings in the greenhouse. Fifteen of these accessions were found to be infected by HSVd, 19 induced reddish marbling, and four induced small blackish spots on the leaves aged about 4 months. Repeated assays showed that these foliar symptoms were not caused by the viroid. Peach red marbling (PRMa) has not been associated with any known virus and seems to be caused by an infectious agent not yet described. That could also be the case with the agent of peach sooty ringspot (PSRS). PRMa and PSRS symptoms were reproduced by grafting and indexing, and their causal agents eliminated by thermotherapy in a significant fraction of the treated plants. They behave like viral agents and can infect the different Prunus species studied.

Characterization by Deep Sequencing of Divergent Plum bark necrosis stem pitting-associated virus (PBNSPaV) Isolates and Development of a Broad-Spectrum PBNSPaV Detection Assay

“…The PR258 sample is affected by the peach red marbling disease (PRMaD), one of the disorders reported on stone fruit trees for which the etiology remains unclear (12,13). This sample was found to be infected by two isolates of PBNSPaV and by a new member of Betaflexiviridae (still under characterization).…”

“…Two Japanese plum (P. salicina) lines, 'Pair' and 'PR258', the latter one affected by the peach red marbling disease (12), and two domestic plum (P. domestica) lines, '387-07-4' and' 369-04-7', were from a germplasm collection in France (CTIFL Lanxade). Various Prunus sources (P. mume, P. domestica, P. salicina, P. persica, P. armeniaca, P. sibirica, P. cerasus, and P. avium) were obtained during several surveys in Azerbaidjan, China, Iran, and Czech Republic in 2005, 2007, 2008, 2009, and 2013.…”

Apricot latent virus - Review

“…As the most susceptible species, P. persica was found to develop yellow asteroid or sooty ring spots on the leaves (Fig. 1), which later became encircled by reddish rings that turn dark; no symptoms were observed on the bark, wood or fruits (Zemtchik, Verderevskaya 1993;Nemchinov, Hadidi 1998;Zemtchik et al 1998;Grasseau et al 1999;Nemchinov et al 2000;Gentit et al 2001 a, b;Abou Ghanem-Sabanadzovic et al 2005, Grimová et al 2010. Among other susceptible species are P. cerasifera, with occasional chlorotic-green spots (Nemchinov, Hadidi 1998), symptomless P. serrulata Shirofungen (Abou Ghanem-Sabanadzovic et al 2005), P. avium, with either no apparent symptoms (Gentit et al 2001b;Grimová et al 2010) or with red to purple rings and mottling of the leaves (Abou Ghanem-Sabanadzovic et al 2005) and asymptomatic P. salicina and P. domestica (Grimová et al 2010).…”