Non-Feeding Transmission Modes of the Tomato Yellow Leaf Curl Virus by the Whitefly Bemisia tabaci Do Not Contribute to Reoccurring Leaf Curl Outbreaks in Tomato

• Published in: Insects (Basel, Switzerland) Vol. 15; no. 10; p. 760
• Main Authors: Marchant, Wendy G, Brown, Judith K, Gautam, Saurabh, Ghosh, Saptarshi, Simmons, Alvin M, Srinivasan, Rajagopalbabu
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30-09-2024; MDPI
• Subjects: Adults; Aleyrodidae; begomovirus; Behavior; Bemisia tabaci; Cotton; Crop yield; Cryptic species; Deoxyribonucleic acid; Disease transmission; DNA; DNA viruses; Endemic species; Environmental aspects; Epidemiology; Exocrine glands; Feeding behavior; Females; Flowers & plants; Genomes; Haplotypes; Infections; Introduced species; Leaf-curl; Leaves; Outbreaks; Phylogenetics; Physiological aspects; Plant diseases; Plant layout; plant transmission; Plant viruses; Polymerase chain reaction; Quantitation; Real time; Sexual transmission; Tomatoes; transovarial transmission; Virions; Virus diseases of plants; Virus-vector relationships; Viruses; Yellow leaf; United States; Middle East; Israel; Georgia; Florida; United States > US; plant transmission; begomovirus; sexual transmission; transovarial transmission
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects15100760

Tomato yellow leaf curl virus (TYLCV) causes significant yield loss in tomato production in the southeastern United States and elsewhere. TYLCV is transmitted by the whitefly
cryptic species in a persistent, circulative, and non-propagative manner. Unexpectedly, transovarial and sexual transmission of TYLCV has been reported for one strain from Israel. In this study, the potential contribution of the
B cryptic species transovarial and sexual transmission of TYLCV (Israel strain, Georgia variant, Georgia, USA) to reoccurring outbreaks was investigated by conducting whitefly-TYLCV transmission assays and virus DNA detection using end point PCR, DNA quantitation via real-time PCR, and virion detection by immunocapture PCR. TYLCV DNA was detectable in four, two, and two percent of first-generation fourth-instar nymphs, first-generation adults, and second-generation adults, respectively, following transovarial acquisition. Post-mating between viruliferous counterparts, the virus's DNA was detected in four percent of males and undetectable in females. The accumulation of TYLCV DNA in whiteflies from the transovarial and/or sexual experiments was substantially lower (100 to 1000-fold) compared with whitefly adults allowed a 48-hr acquisition-access period on plants infected with TYLCV. Despite the detection of TYLCV DNA in whiteflies from the transovarial and/or mating experiments, the virions were undetectable by immunocapture PCR-a technique specifically designed to detect virions. Furthermore, tomato test plants exposed to whitefly adults that presumably acquired TYLCV transovarially or through mating remained free of detectable TYLCV DNA. Collectively, the extremely low levels of TYLCV DNA and complete absence of virions detected in whiteflies and the inability of the
cryptic species B to transmit TYLCV to test tomato plants following transovarial and mating acquisition indicate that neither transovarial nor sexual transmission of TYLCV are probable or epidemiologically relevant for TYLCV persistence in this pathosystem.