Molecular characterization of an Apulian isolate of tomato leaf curl New Delhi virus.

Tomato leaf curl New Delhi virus (ToLCNDV) is an emerging begomovirus (Geminiviridae family) whose economic importance in the Mediterranean basin correlates with recurrent outbreaks in tomato and in cucurbits with estimated losses between 30 and 100%. In Apulia (southern Italy), the virus was isolated in 2018 in commercial fields of zucchini squash and melon and in 2020 in protected crops of zucchini squash with heavy infestations of aleyrodids. ToLCNDV genome consists of two circular single-stranded DNA molecules of about 2.7–2.6 kb, referred to as DNA-A and DNAB, encapsidated in geminate particles. Betasatellites could be associated with DNA affecting replication, movement within host, horizontal transmission between plants and inducing severe disease symptoms and suppression of transcriptional gene silencing. We sampled zucchini squash during 2020 outbreaks and obtained the whole sequence of the DNA-A of one of the isolates for which the name of ToLCNDV-Le is proposed. Phylogenetic analysis of the CP sequences of ToLCNDV-Le with those of 42 ToLCNDV isolates from different countries and plant species, retrieved from the public database placed ToLCNDV-Le among the Spain strains (ToLCNDV-ES) of the virus as it shares more than 94% nucleotide identity, according to ICTV strain demarcation criteria. Characteristics of the fully sequenced DNA-A of ToLCNDV-Le using the Illumina 2 × 150 bp reads platform and WGS application with a 100 × depth of coverage will be reported. Since recombination has been previously reported for ToLCNDV, we examined the ToLCNDV-Le DNA-A for any evidence of recombination as well as for its association with betasatellites.