Non-feeding transmission modes of Tomato yellow leaf curl virus-IL by the whitefly Bemisia tabaci B mitotype might not contribute to reoccurring leaf curl outbreaks in tomato

Authors: MARCHANT, WENDY - University Of Georgia; BROWN, JUDITH - University Of Arizona; GAUTAM, SAURABH - University Of Georgia; GHOSH, SAPTARSHI - University Of Georgia; Simmons, Alvin; SRINIVASAN, RAJAGOPALBABU - University Of Georgia

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: The whitefly-transmitted tomato yellow leaf curl virus-Israel causes yield loss in tomato, pepper, and other solanaceous crops. Previous reports indicate that this virus can be transmitted between male and female whiteflies during mating as well as being able to be transmitted to the offspring when the females lay eggs. In our research, this virus was detected in 4% of first generation fourth-instar whitefly nymphs, and in 2% of first- and second-generation adult whiteflies. Also, after mating with an infected partner, the virus DNA was detected in 4% of the male partner while there was no detection in the female partner. The low level of transmission between insects did not result to any transmission to plants which suggests that this is of little or no importance during crop production. This information is useful for researchers to understand and manage the spread of the Tomato yellow leaf curl virus-Israel in crops.

Technical Abstract: Tomato yellow leaf curl virus-Israel (TYLCV-IL) causes significant yield loss in tomato and other solanaceous crops. TYLCV-IL is transmitted by Bemisia tabaci in a persistent, circulative, and non-propagative manner. Transovarial and sexual transmission of TYLCV has been reported for the same strain of TYLCV (TYLCV-IL). In this study, the potential contribution of B. tabaci mitotype B transovarial and sexual transmission of TYLCV-IL (Georgia isolate, Georgia, USA) for reoccurring outbreaks was investigated by conducting whitefly-TYLCV-IL transmission assays and virus detection using end point PCR, virus quantitation via real-time PCR, and immunocapture PCR amplification of viral genomic DNA. TYLCV-IL was detectable in 4% and 2% of first generation fourth-instar nymphs, and first- and second-generation adults, respectively. Post-mating with viruliferous counterparts, virus DNA was detected in 4% of males and zero females. The accumulation of TYLCV-IL DNA in whiteflies from the transovarial and/or sexual transmission experiments was substantially lower (100 to 1000-fold) compared with whiteflies allowed a 48-hr acquisition-access period on plants infected with TYLCV-IL. Despite the detection of TYLCV-IL DNA in whiteflies from the transovarial and/or mating transmission experiments, virions were undetectable by immunocapture PCR. Tomato test plants exposed to whiteflies in the transovarial or mating experiments remained free of detectable TYLCV-IL DNA. Collectively, the extremely low detection of TYLCV-DNA or no detection of virions in whiteflies, and the inability of B. tabaci mitotype B to transmit TYLCV-IL to tomato test plants indicate that neither transovarial nor sexual transmission of TYLCV-IL are probable or biologically relevant for TYLCV-IL persistence in this pathosystem.