scholarly journals Citrullus ecirrhosus: Wild Source of Resistance Against Bemisia tabaci (Hemiptera: Aleyrodidae) for Cultivated Watermelon

2019 ◽  
Vol 112 (5) ◽  
pp. 2425-2432 ◽  
Author(s):  
Alvin M Simmons ◽  
Robert L Jarret ◽  
Charles L Cantrell ◽  
Amnon Levi

Abstract Members of the highly polyphagous Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) species complex cause major crop damage by feeding and by transmitting plant viruses. The Middle East-Asia Minor 1 (MEAM1) of the B. tabaci complex is by far the most problematic whitefly affecting crops including cultivated watermelon (Citrullus lanatus; Cucurbitaceae: Cucurbitales). Watermelon cultivars share a narrow genetic base and are highly susceptible to whiteflies. We studied the potential of C. ecirrhosus, a perennial desert species that can be hybridized with C. lanatus, as a source of whitefly resistance for cultivated watermelon. The results of this study indicate that C. ecirrhosus offers resistance (although not total) against the MEAM1 B. tabaci based on, at least, antibiosis and antixenosis. Whitefly performance concerning developmental survival, body size attainment, and nonpreference were suppressed on C. ecirrhosus compared with the watermelon cultivar ‘Sugar Baby’. Also, our olfactometer results indicated that the adults were less attracted to leaf volatiles of C. ecirrhosus. Although there is a pungent odor associated with the leaves of C. ecirrhosus, the leaf volatiles had no toxic effect on adult whitefly survival as compared with cultivated watermelon. We also demonstrated that plants of C. ecirrhosus can be clonally propagated from vine cuttings of the parent plant. Using traditional breeding procedures, C. ecirrhosus was hybridized with C. lanatus and viable F1 and F2 seeds were produced. This is the first report of pest resistance in C. ecirrhosus. This wild species offers a source of resistance against whiteflies for the improvement of cultivated watermelon.

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1028
Author(s):  
Bruna Pinheiro-Lima ◽  
Rita C. Pereira-Carvalho ◽  
Dione M. T. Alves-Freitas ◽  
Elliot W. Kitajima ◽  
Andreza H. Vidal ◽  
...  

The knowledge of genomic data of new plant viruses is increasing exponentially; however, some aspects of their biology, such as vectors and host range, remain mostly unknown. This information is crucial for the understanding of virus–plant interactions, control strategies, and mechanisms to prevent outbreaks. Typically, rhabdoviruses infect monocot and dicot plants and are vectored in nature by hemipteran sap-sucking insects, including aphids, leafhoppers, and planthoppers. However, several strains of a potentially whitefly-transmitted virus, papaya cytorhabdovirus, were recently described: (i) bean-associated cytorhabdovirus (BaCV) in Brazil, (ii) papaya virus E (PpVE) in Ecuador, and (iii) citrus-associated rhabdovirus (CiaRV) in China. Here, we examine the potential of the Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) to transmit BaCV, its morphological and cytopathological characteristics, and assess the incidence of BaCV across bean producing areas in Brazil. Our results show that BaCV is efficiently transmitted, in experimental conditions, by B. tabaci MEAM1 to bean cultivars, and with lower efficiency to cowpea and soybean. Moreover, we detected BaCV RNA in viruliferous whiteflies but we were unable to visualize viral particles or viroplasm in the whitefly tissues. BaCV could not be singly isolated for pathogenicity tests, identification of the induced symptoms, and the transmission assay. BaCV was detected in five out of the seven states in Brazil included in our study, suggesting that it is widely distributed throughout bean producing areas in the country. This is the first report of a whitefly-transmitted rhabdovirus.


2020 ◽  
Vol 110 (5) ◽  
pp. 567-576 ◽  
Author(s):  
D. J. Kriticos ◽  
P. J. De Barro ◽  
T. Yonow ◽  
N. Ota ◽  
R. W. Sutherst

AbstractThe Bemisia tabaci species complex is one of the most important pests of open field and protected cropping globally. Within this complex, one species (Middle East Asia Minor 1, B. tabaci MEAM1, formerly biotype B) has been especially problematic, invading widely and spreading a large variety of plant pathogens, and developing broad spectrum pesticide resistance. Here, we fit a CLIMEX model to the distribution records of B. tabaci MEAM1, using experimental observations to calibrate its temperature responses. In fitting the model, we consider the effects of irrigation and glasshouses in extending its potential range. The validated niche model estimates its potential distribution as being considerably broader than its present known distribution, especially in the Americas, Africa and Asia. The potential distribution of the fitted model encompasses the known distribution of B. tabaci sensu lato, highlighting the magnitude of the threat posed globally by this invasive pest species complex and the viruses it vectors to open field and protected agriculture.


2021 ◽  
Author(s):  
Andrew Cuthbertson

Abstract The exact origin of the MED species of Bemisia tabaci, and the reasons why it became such an important pest are still not fully known. MED species has been identified as a distinct member within the B. tabaci species complex (Tay et al., 2012). MED species is also an effective vector of many different plant viruses which, in conjunction with its high level of polyphagy, make it extremely problematic within agricultural regions where crops may be susceptible to viruses acquired from indigenous plants. Despite Bemisia in general being a tropical/sub-tropical whitefly species, MED species can easily be transported on plant species to temperate regions of the world (Cuthbertson and Vänninen, 2015). Within these cooler regions, MED species can survive within a protected environment and could feasibly spread virus diseases to new locations. It is for this reason that B. tabaci and members of its species complex, including MED species are on EPPO A2 Alert list.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1700
Author(s):  
Yun-Yun Fan ◽  
Yu-Wei Zhong ◽  
Jing Zhao ◽  
Yao Chi ◽  
Sophie Bouvaine ◽  
...  

Begomoviruses cause substantial losses to agricultural production, especially in tropical and subtropical regions, and are exclusively transmitted by members of the whitefly Bemisia tabaci species complex. However, the molecular mechanisms underlying the transmission of begomoviruses by their whitefly vector are not clear. In this study, we found that B. tabaci vesicle-associated membrane protein 2 (BtVAMP2) interacts with the coat protein (CP) of tomato yellow leaf curl virus (TYLCV), an emergent begomovirus that seriously impacts tomato production globally. After infection with TYLCV, the transcription of BtVAMP2 was increased. When the BtVAMP2 protein was blocked by feeding with a specific BtVAMP2 antibody, the quantity of TYLCV in B. tabaci whole body was significantly reduced. BtVAMP2 was found to be conserved among the B. tabaci species complex and also interacts with the CP of Sri Lankan cassava mosaic virus (SLCMV). When feeding with BtVAMP2 antibody, the acquisition quantity of SLCMV in whitefly whole body was also decreased significantly. Overall, our results demonstrate that BtVAMP2 interacts with the CP of begomoviruses and promotes their acquisition by whitefly.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Soňa Vyskočilová ◽  
Wee Tek Tay ◽  
Sharon van Brunschot ◽  
Susan Seal ◽  
John Colvin

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1808
Author(s):  
Saptarshi Ghosh ◽  
Murad Ghanim

Many plant viruses depend on insect vectors for their transmission and dissemination. The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important virus vectors, transmitting more than four hundred virus species, the majority belonging to begomoviruses (Geminiviridae), with their ssDNA genomes. Begomoviruses are transmitted by B. tabaci in a persistent, circulative manner, during which the virus breaches barriers in the digestive, hemolymph, and salivary systems, and interacts with insect proteins along the transmission pathway. These interactions and the tissue tropism in the vector body determine the efficiency and specificity of the transmission. This review describes the mechanisms involved in circulative begomovirus transmission by B. tabaci, focusing on the most studied virus in this regard, namely the tomato yellow leaf curl virus (TYLCV) and its closely related isolates. Additionally, the review aims at drawing attention to the recent knowhow of unorthodox virus—B. tabaci interactions. The recent knowledge of whitefly-mediated transmission of two recombinant poleroviruses (Luteoviridae), a virus group with an ssRNA genome and known to be strictly transmitted with aphids, is discussed with its broader context in the emergence of new whitefly-driven virus diseases.


Author(s):  
Wanaporn Wongnikong ◽  
James P. Hereward ◽  
Sharon L. van Brunschot ◽  
Justin K. Cappadonna ◽  
Gimme H. Walter

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 11
Author(s):  
Jain ◽  
Robinson ◽  
Mitter

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a significant global pest of economically important vegetable, fibre, and ornamental crops. Whiteflies directly damage the plants by piercing and sucking essential nutrients, indirectly through honeydew secretion and by transmitting more than 200 plant viruses that cause millions of dollars in produce losses per year. Whitefly management is mostly reliant on the heavy use of chemical insecticides. However, this ultimately leads to increasing resistance development, detrimental effects on beneficial insects and biomagnification of ecologically harmful chemicals in the environment. Responding to consumer demands for more selective, less toxic, non-GM insect control strategies, RNA interference (RNAi) has emerged as a potential game-changing solution. The RNA interference (RNAi) is a homology-dependent mechanism of gene silencing that represents a feasible and sustainable technology for the management of insect pests. In the present study, twenty-two whitefly genes were selected based on their essential function in the insect and tested in artificial diet bioassays for mortality and gene silencing efficacy. The nine most effective dsRNA constructs showed moderate-to-high whitefly mortality as compared to negative controls six days post-feeding. qPCR analysis further demonstrated significant knockdown of target gene mRNA expression. Additionally, uptake and spread of fluorescently labelled dsRNA was evident beyond the midgut of the whitefly supporting the systemic spreading of RNAi effectors. Taken together, the oral delivery of dsRNA shows effective RNAi mediated gene silencing of target genes and offers a viable approach for the development of dsRNA biopesticides against hemipteran pest.


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