Incidence of Peach Latent Mosaic Viroid (PLMVd) in a Prunus persica Bastch Germplasm Collection in Spain

Abstract

Plant material free of pests and diseases is an essential requirement for obtaining high fruit quality in productive orchards. Unfortunately, the increase of genetic diversity has prevailed until now in most germplasm collections over the health status of the accessions. As a consequence, most fruit tree germplasm collec-tions are infected with viruses and viroids and maintained in non-optimal conditions. The incidence of Peach latent mosaic viroid (PLMVd) was assessed in the Spanish Peach Germplasm Collection located at the CITA in Zaragoza (Spain). This germplasm collection is composed by more than 400 peach and nectarine cultivars, including new and old international commercial cultivars as well as autochthonous interesting genotypes, such as clingstone peaches, both of yellow and white flesh, and flat peaches. PLMVd infection was firstly detected by visual symptom observation of the characteristic leaf yellowing, discoloration along leaf sides and peach calico. PLMVd infection spreading was assessed in a total of 402 peach varieties by non-isotopic dot-blot hybridization and by RT-PCR analysis. PLMVd was detected in 219 cultivars (54.0%), and this result was corroborated by RT-PCR for 90% of them. From the infected cultivars, only 115 (52.5%) showed clear symptoms of the infection, revealing the necessity of applying this type of analysis for PLMVd diagnosis. PLMVd incidence seems not to be associated with variety origin; however, it tends to increase with the age of the trees. This may imply either that infection is spreading into the collection or that the newest varieties have been obtained from healthy plant material. The high infection level observed in the peach germplasm collection shows the importance of this disease in this fruit tree species and the pressing need of sanitation to preserve this valuable genetic resource. To ascertain the origin of the infection in this collection twelve PLMVd isolates were sequenced. The corresponding phylogenetic analysis showed two clear clusters, strongly suggesting that the infection could have occurred in two different events along the planting system.

Published in

Acta Horticulturae
2012, Volume: 940, pages: 687-692 ISBN: 978-90-66056-85-5Publisher: ISHS

Conference

XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on the Challenge for a Sustainable Production, Protection and Consumption of Mediterranean Fruits and Nuts

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.17660/ActaHortic.2012.940.95

Permanent link to this page (URI)

https://res.slu.se/id/publ/99980