Detection and characterization of tomato leaf curl New Delhi virus association with mosaic disease of ivy gourd (Coccinia grandis (L.) Voigt) in North India

Abstract

Sixteen ivy gourd (Coccinia grandis (L.) Voigt) plant samples showing severe mosaic symptoms were collected from New Delhi and Varanasi (Uttar Pradesh) in India. Begomovirus infection was confirmed by PCR using begomovirusspecific primers. Amplified PCR products (1.2 kb fragments) were cloned and the sequence was characterized. Based on sequence analysis, begomovirus associated with the majority of ivy gourd samples (16) was found to be a member of a bipartite begomovirus species, which is closely related to tomato leaf curl New Delhi virus (ToLCNDV). Therefore, two samples of ivy gourd, IVG1-ND and IVG2-Var, were selected for full-length genome (DNA-A and DNA-B-like sequence) amplification by the rolling circle DNA amplification (RCA) method. Sequence analysis performed using the Species Demarcation Tool (SDT) program revealed that they share 89.5-91.3% (IVG1-ND) and 93.4-96.8% (IVG2-Var) nucleotide (nt) identity with the DNA-A-like sequence of ToLCNDV isolated from cucurbits and chilli, respectively. The IVG1-ND and IVG2-Var isolates shared 90% nt identity among themselves, indicating that they are two different strains of ToLCNDV. Similarly, SDT analysis of the DNA-B-like sequence of IVG1-ND and IVG2-Var exhibited showed 82.7-93.3% nt identity with the DNA-B-like sequences of ToLCNDV infecting cucurbits. The recombination analysis of DNA-A and DNB-B-like sequences showed that the greater part of their genome most likely originated from previously reported begomoviruses that are known to infect chilli and cucurbits through recombination.

Characterization of begomoviruses associated with emerging mosaic disease of ivy gourd (Coccinia grandis L.) in Tamil Nadu, India

“…ToLCNDV infection was first observed in tomato (Padidam et al , 1995) and later identified in different solanaceous and cucurbitaceous vegetables (Arguello- Astorga et al , 2001 andHanley-Bowdoin et al , 1999). Venkataravanappa et al , (2018) documented 60 to 70% disease incidence of ToLCNDV on ivy gourd collected from New Delhi and Uttar Pradesh, showing mosaic, blistering and stunted incidence. Begomoviruses are extending their host range to infect 98.6% in major cucurbits such as ash gourd, pumpkin, bitter gourd, bottle gourd, snake gourd, cucumber, ivy gourd and watermelon from Tamil Nadu (Nagendran et al 2017).…”

“…In addition, asymptomatic plants of IGP-1 isolate were also yielded an amplicon of ~1200 bp fragment. Venkataravanappa et al (2018) used begomovirus specific primer for amplifying 1.2 kb genome fragment for sixteen ToLCNDV isolate infecting ivy gourd samples. Nagendran et al (2016) used coat protein specific (Deng 540/541) primer for identifying begomovirus in ivy gourd mosaic infected samples and subsequently cloned the full length genome through RCA and identified new Begomovirus species CoMoV in Tamil Nadu.…”

“…There are about 24 begomovirus species are reported to be infecting cucurbits globally (Kumari et al 2022). Among them, tomato leaf curl New Delhi virus (ToLCNDV) and Coccinia mosaic virus (CoMoV) were previously reported be infecting ivy gourd in India ISSN-0970-6585 (Print), ISSN-2455-7552 (Online) (Venkataravanappa et al 2018;Nagendran et al 2016). Among these, ToLCNDV has emerged as a significant problem in several cucurbit crops (Zaidi et al 2017) and other traits (Garg 2020, Rahman et al 2020, Karmakar et al 2021, Pandey et al 2021.…”

Pest categorisation of tomato leaf curl New Delhi virus

“…In Asia, there are a few records of ToLCVND on other crops such as Hibiscus cannabinus (kenaf – Malvaceae), Carica papaya (papaya – Caricaceae), Daucus carota (carrot – Apiaceae), Vigna radiata (mung bean – Fabaceae) Abelmoschus esculentus (okra – Malvaceae) and Glycine max (soyabean – Fabaceae) (Jamil et al., ; Moriones et al., ; Zaidi et al., 2017b; Pant et al., ; Venkataravanappa et al., ; EPPO, online), while habanero pepper ( Capsicum chinense – Solanaceae ) was infected when challenged with viruliferous whiteflies in laboratory studies (Ruíz et al., ). All these hosts of ToLCNDV are also confirmed hosts of B. tabaci (EFSA PLH Panel, ; Leite et al., ).…”

“…The natural host range of ToLCNDV counts more than 58 plant species, including important vegetable and ornamental species that belong, among others, to the Solanaceae , Cucurbitaceae , Fabaceae and Malvaceae families (Fortes et al., ; Nagendran et al., 2017b; Zaidi et al., 2017b; Pant et al., ; Venkataravanappa et al., , ; Juárez et al., ; Anwar et al., ; Ashwathappa et al., ; EPPO, online).…”