Identification of Begomoviruses from Three Cryptic Species of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in Nepal

Rajendra Acharya,Yam Kumar Shrestha,Kyeong-Yeoll Lee,Mst Fatema Khatun

doi:10.3390/agronomy11102032

Abstract

The Bemisia tabaci species complex consists of at least 44 cryptic species, which are potential vectors of approximately 320 begomovirus species, most of which are significant plant viruses. However, the relationship of begomovirus transmission through vectors at the cryptic species level is uncertain. In our previous study, three cryptic species (Asia I, Asia II 1, and Asia II 5) of B. tabaci were identified from 76 B. tabaci samples collected across 23 districts in Nepal. Using the same individuals we identified seven different begomovirus species (Squash leaf curl China virus [SLCCNV], Tomato leaf curl New Delhi virus [ToLCNDV], Okra enation leaf curl virus [OELCuV], Synedrella leaf curl virus [SyLCV], Tomato leaf curl Kerala virus [ToLCKeV], Ageratum enation virus [AEV], and Tomato leaf curl Karnataka virus [ToLCKV]) by PCR using universal begomovirus primers. The begomoviruses were detected in 55.26% of whitefly samples, and SLCCNV was the most prevalent species (27.63%). Among the three cryptic species of B. tabaci, the virus detection rate was highest in Asia I (60%), followed by Asia II 1 (58.82%) and Asia II 5 (53.06%). Most viruses were detected in all three species, but AEV and ToLCKV were found only in Asia I and Asia II 1, respectively. Geographic analysis showed that SLCCNV was distributed in the whole country, which is similar to the distribution of the Asia II 5 species, but OELCuV and SyLCV were detected only in the middle region of Nepal. Our results provide important information on the begomovirus profile in Nepal which can be beneficial for plant virus risk assessment and develop the management strategies to reduce the damage of whitefly transmitted viruses.

Highlights

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a vector of at least 320 plant viruses of the genera Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Polerovirus and Torradovirus [1,2,3,4]
B. tabaci is the only vector of Begomovirus, such as the Tomato yellow leaf curl virus (TYLCV), Tomato leaf curl New Delhi virus (ToLCNDV), Squash leaf curl China virus (SLCCNV), and African cassava mosaic virus (ACMV) [5]
We identified 7 different begomoviruses: the SLCCNV, ToLCNDV, Okra enation leaf curl virus (OELCuV), Synedrella leaf curl virus (SyLCV), Tomato leaf curl Kerala virus (ToLCKeV), Ageratum enation virus (AEV), and Tomato leaf curl Karnataka virus (ToLCKV) from three cryptic species of B. tabaci collected from 18 districts in Nepal (Figures 1 and 2)

Summary

Introduction

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a vector of at least 320 plant viruses of the genera Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Polerovirus and Torradovirus [1,2,3,4]. B. tabaci is the only vector of Begomovirus, such as the Tomato yellow leaf curl virus (TYLCV), Tomato leaf curl New Delhi virus (ToLCNDV), Squash leaf curl China virus (SLCCNV), and African cassava mosaic virus (ACMV) [5] These viruses can be transmitted in a persistent, circulative, and non-propagative manner [1,6]. Mediterranean (MED)—are highly invasive and cause significant economic damage to various crops worldwide, whereas most other cryptic species are indigenous to specific regions (i.e., Asia and Africa) [16]. This species has a broad host range of at least 600 different plant species [17]. These characteristics of B. tabaci indicate that this species has significant potential to transmit plant viruses into various crops and spread them widely into most countries across the world

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Conclusion