Molecular characterization of two apple mosaic virus isolates and construction of an ApMV infectious cDNA clone
Y. XIANG (1), Z. Li (2), B. Bhagwat (1), J. Holmes (1), M. Bernardy (1), Y. Wu (2) (1) Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Canada; (2) College of Plant Protection, Northwest A&F University, China

Apple mosaic virus (ApMV) is a species belonging to the genus Illarvirus, in the family Bromoviridae, and has a tripartite positive-sense single-stranded RNA genome. The virus infects diverse species of Rosales and is often observed in mixed infections with other fruit tree viruses. We analyzed the ApMV genome and its variants in two ApMV-infected apple disease samples from the Canadian Plant Virus Collections (CPVC). ApMV was found in mixed infections with Apple chlorotic leaf spot virus, Apple green crinkle associated virus, Apple stem grooving virus, Apple stem pitting virus and Apricot latent virus in the disease samples. The two ApMV isolates (CPVC457 and CPVC637) share ~97% identity at nucleotide level for all three RNA segments. Low frequency variant analysis suggested an existence of a major ApMV genome population mixed with dozens of minor genome variants at low to intermediate frequencies in the infected samples. We cloned full-length cDNAs of the tripartite RNA genome of ApMV CPVC637, engineered the cDNAs in a plant binary vector and tested its infectivity in cucumber plants via Agrobacterium-mediated infiltration. The inoculated plants displayed symptoms of leaf chlorosis, twisted leaf, venial necrosis and stunted growth. The production of the virus RNA segments in the infected leaves were confirmed by RT-PCR, suggesting the ApMV cDNA clones can systemically infect the plants.

Abstract Number: P11-386
Session Type: Poster