Alfalfa leaf curl virus is efficiently acquired by its aphid vector Aphis craccivora but inefficiently transmitted

Physical contact transmission of Cucumber green mottle mosaic virus by Myzus persicae

Cucumber green mottle mosaic virus (CGMMV), a critical plant virus, has caused significant economic losses in cucurbit crops worldwide. It has not been proved that CGMMV can be transmitted by an insect vector. In this study, the physical contact transmission of CGMMV by Myzus persicae in Nicotiana benthamiana plants was confirmed under laboratory conditions. The acquisition rate increased with time, and most aphids acquired CGMMV at 72 h of the acquisition access period (AAP). Besides, the acquired CGMMV was retained in the aphids for about 12 h, which was efficiently transmitted back to the healthy N. benthamiana plants. More importantly, further experiments suggested that the transmission was mediated by physical contact rather than the specific interaction between insect vector and plant virus. The results obtained in our study contribute to the development of new control strategies for CGMMV in the field.

Genome characterization and diversity of trifolium virus 1: identification of a novel legume-infecting capulavirus

A novel geminivirus was identified in France and Spain in asymptomatic plants of white clover (Trifolium repens) and shrub medick (Medicago arborea). Its genome has the hallmarks of a capulavirus, and its relationship to other capulaviruses was confirmed by phylogenetic analysis. White clover isolates formed a tight cluster in the phylogenetic tree, while shrub medick isolates formed two distinct, more divergent groups with sequence identity values close to the species cutoff. These three groups have likely participated in recombination events involving alfalfa leaf curl virus and French bean severe leaf curl virus. The name "trifolium virus 1" (TrV1) is proposed for this new Capulavirus. Three TrV1 genotypes (TrV1-A, TrV1-B, and TrV1-C) were clearly distinguished.