Biological properties of apple scar skin viroid: Isolates, host range, different sensitivity of apple cultivars, elimination, and natural transmission

Citation
Jc. Desvignes et al., Biological properties of apple scar skin viroid: Isolates, host range, different sensitivity of apple cultivars, elimination, and natural transmission, PLANT DIS, 83(8), 1999, pp. 768-772
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
PLANT DISEASE
ISSN journal
0191-2917 → ACNP
Volume
83
Issue
8
Year of publication
1999
Pages
768 - 772
Database
ISI
SICI code
0191-2917(199908)83:8<768:BPOASS>2.0.ZU;2-O
Abstract
Studies conducted over the last 10 years have revealed that the disease cau sed by the apple scar skin viroid (ASSVd) is extremely rare in Europe. ASSV d was detected by molecular hybridization and indexing in field plots on th e apple indicators Starkrimson and Indo, which showed symptoms of dapple ap ple disease within 2 years, and rough scarred skin within 3 years, respecti vely, Results from both approaches were in agreement. In an attempt to impr ove the biological detection of ASSVd the Japanese PK13 isolate was inocula ted to 4 Prunus, 13 Malus, 17 Pyrus, and 17 other pomaceous species. All th e species tested of the Malus, Pyrus, Sorbus, Chaenomeles, Cydonia, and Pyr onia genera were susceptible to ASSVd based upon back indexing and hybridiz ation, but none developed leaf or bark symptoms during a 2-year period. The viroid was not detected in the tested members of genera Amelanchier; Aroni a, Cotoneaster, Crataegus, Prunus, and Pyracantha. Symptoms on fruit of 42 commercial apple cultivars experimentally inoculated with ASSVd fell into f ive groups ranging from inconspicuous spots to severely scarred skin and cr acking. ASSVd was eliminated from most of the infected apple plants when th ey were subjected to a dormant stage followed by thermotherapy and shoot ti p grafting. Analysis of more than 400 apple seedlings, originated from Star krimson and Indo fruits with typical ASSVd symptoms, showed that there is l ittle or no seed transmission of this viroid. However, ASSVd was transmitte d at a low rate under field conditions to adjacent trees.