Identification, Characterization, and Molecular Detection of Alfalfa mosaic virus in Potato

Abstract

Alfalfa mosaic virus (AMV) was detected in potato fields in several provinces in Canada and characterized by bioassay, enzyme-linked immunosorbent assay, and reverse-transcription polymerase chain reaction (RT-PCR). The identity of eight Canadian potato AMV isolates was confirmed by sequence analysis of their coat protein (CP) gene. Sequence and phylogenetic analysis indicated that these eight AMV potato isolates fell into one strain group, whereas a slight difference between Ca175 and the other Canadian AMV isolates was revealed. The Canadian AMV isolates, except Ca175, clustered together among other strains based on alignment of the CP gene sequence. To detect the virus, a pair of primers, AMV-F and AMV-R, specific to the AMV CP gene, was designed based on the nucleotide sequence alignment of known AMV strains. Evaluations showed that RT-PCR using this primer set was specific and sensitive for detecting AMV in potato leaf and tuber samples. AMV RNAs were easily detected in composite samples of 400 to 800 potato leaves or 200 to 400 tubers. Restriction analysis of PCR amplicons with SacI was a simple method for the confirmation of PCR tests. Thus, RT-PCR followed by restriction fragment length polymorphism analysis may be a useful approach for screening potato samples on a large scale for the presence of AMV.

The spreading of Alfalfa mosaic virus in lavandin in Croatia

“…The phylogenetic analysis based on the nucleotide sequence of the CP gene showed that the AMV isolates from Croatia and 26 other AMV isolates might be divided into four distinct molecular groups. Although a previous study had shown that AMV isolates from France and Italy fell into two distinct subgroups (Parrella et al, 2000), our phylogenetic data analysis of AMV strains are in agreement with those of Xu and Nie (2006) and Stanković et al (2011), who found that AMV isolates may be divided into four distinct molecular groups. Two isolates originating from the Croatian localities Banovo Brdo and Vinkovci (70-12 and 373-13, respectively) clustered within the molecular group IV, but the isolate 371-13, originating from the locality Belišće, fell into a different molecular group (group III).…”

“…Two isolates originating from the Croatian localities Banovo Brdo and Vinkovci (70-12 and 373-13, respectively) clustered within the molecular group IV, but the isolate 371-13, originating from the locality Belišće, fell into a different molecular group (group III). Similarly, it has been reported that Canadian potato AMV isolates grouped in two different clusters (Xu & Nie, 2006). Our analysis also indicated that the Croatian AMV isolates did not share a recent common ancestor, representing two distinct lineages of AMV in Croatia.…”

Genetic Comparison Between Coat Protein Gene of Alfalfa mosaic virus Isolate Infecting Potato Crop in Upper Egypt and Worldwide Isolates

“…Sequencing of CP gene of AMV-Assiut isolate showed that this isolate shared high degree of variability with other AMV isolates, this variability ranged from 4.8-10% in case of AMV isolate form Egypt (Wade Elnatron) and isolate from Brazil, respectively. This degree of variation was similar to the degree of variability reported before by Al-Saleh and Amer (2013), who mentioned that AMV isolates from Saudi-Arabia shared similarity ranged from 90.3-99.3% with AMV worldwide isolates and Xu and Nie (2006), who revealed that the level of variation in CP among AMV isolates was up to 7% in amino acid sequence and up to 10% in nucleotide sequences. Moreover these data was in agreement with Parrella et al (2010), who showed that variation in CP genes of AMV worldwide isolates was up to 7% at the nucleotide level.…”

“…In Egypt, AMV appeared on potato plants in several location causing severe lose (El-Helaly et al, 2012). Information about degree of variation in AMV and comparison among AMV strains from other countries will lead to better understanding of the similarities and differences among AMV isolates and will help to design a proper approach for detection and management of this virus (Xu and Nie, 2006). …”

“…The AMV particles are composed of icosahedral capsids measuring 30-57 nm in length and 18 nm in diameter (Thole et al, 1998). The genome of AMV consists of three single strand RNA molecules of plus sense polarity, conventionally numbered RNA 1-3 of decreasing size (Xu and Nie, 2006), encapsidated into B, M and T components, respectively (Jaspars, 1985). It is transmitted by aphids in non-persistent way (Hull, 1969).…”