The competence of four thrips species to transmit and replicate four tospoviruses

Abstract

The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well-known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis , F. schultzei , Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi . Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body.

The glycoprotein gene of Chrysanthemum stem necrosis virus and Zucchini lethal chlorosis virus and molecular relationship with other tospoviruses

“…From virus-plant-vector interaction studies, it is evident that TSWV and CSNV share many common features, such as very similar host range and response [9, T. Nagata unpublished data] and the vector specificity [34]. Remarkably, ZLCV shows distinct biological characteristics from those of other Brazilian tospoviruses, as TSWV, CSNV, TCSV, and GRSV.…”

“…Chrysanthemum stem necrosis virus (CSNV), which was first isolated from Chrysanthemum spp. in Brazil, shares many biological features with TSWV, as host range, symptoms in indicator plants and vector specificity [9,34]. However, another Brazilian tospovirus, Zucchini lethal chlorosis virus (ZLCV), show less similarity to any other tospovirus described so far, e.g., adaptation to cucurbits hosts [9] and restricted vector specificity (T. Nagata, unpublished data).…”

The phylogeny of thrips (Thysanoptera: Thripidae) based on partial sequences of cytochrome oxidase I, 28S ribosomal DNA and elongation factor-1 α and the association with vector competence of tospoviruses

“…The order Thysanoptera is considered monophyletic based on morphological and molecular characteristics (Mound et al, 1980;Crespi et al, 1996). Presently, twelve thrips species are recognized as vectors transmitting tospoviruses (Bunyaviridae), including 16 virus species (Reddy et al, 1991;Yeh et al, 1992;Chen and Chiu, 1996;Mumford et al, 1996;Singh and Krishnareddy, 1996;Webb et al, 1997;Cortês et al, 1998;Gera et al, 1998;Bezerra et al, 1999;Kato et al, 1999;Nagata and de Ávila, 2000;Lee et al, 2002;Ullman et al, 2002;Nagata et al, 2004;Ghotbi et al, 2005;Lin et al, 2005;Premachandra et al, 2005;Ohnishi et al, 2006).…”

Effect of Different Mulch Colors on Cucumber Production

“…Generally, fewer thrips, aphids, cucumber moths and whiteflies were noted on plants on Silvery grey colored mulch compared to other colored mulches. Díaz-Pérez et al, (2003); Momol et al, (2004);Nagata et al, (2004) and Stavisky et al, (2002) attributes this to the insect-repellant characteristic of metalized mulches. At peak period, the reduced number of fruits and reduced marketable yields on the Blue colored mulch may also have been due to the large number of thrips that was attracted to the Blue colored mulch from early in the season and remained relatively high throughout the growing season.…”