Experimental and molecular evidence of Reptalus panzeri as a natural vector of bois noir

Abstract

Bois noir (BN) is an economically important grapevine yellows disease induced by the stolbur phytoplasma and principally vectored by the cixiid Hyalesthes obsoletus. This study addresses the involvement of other planthoppers and/or leafhoppers in BN epidemics in the South Banat district of northeastern Serbia, by performing transmission experiments and multilocus typing of stolbur phytoplasma isolates to determine the vector-related characteristics of the disease. Transmission trials were conducted with adults of two cixiid congeners, Reptalus panzeri and R. quinquecostatus, which were found to harbour stolbur phytoplasma in the vineyards under study. A molecular characterization of stolbur phytoplasma isolates was performed by sequence analysis and/or RFLP typing of the two housekeeping genes tuf and secY and the two membrane proteins stamp and vmp1. Transmission trials with naturally infected R. panzeri adults from either the BN-infected vineyards or maize redness (MR)-affected maize fields revealed a high stolbur phytoplasma transmission efficiency to grapevines. In contrast, experiments conducted with stolbur-positive R. quinquecostatus originating from BN-infected vineyards, provided no evidence for a vector role of this species. Seven stolbur phytoplasma genotypes, all of which were tuf-b types, were detected among the grapevine-and insect-associated field samples according to the tuf/secY/vmp1/stamp typing. STOLg was the genotype most frequently found in naturally infected grapevine (42%), as well as R. panzeri originating from the vineyards (85%) and maize fields (98%). The same genotype was found in all experimental plants inoculated by R. panzeri, confirming its vectorship of the disease.

The molecular epidemiology of bois noir grapevine yellows caused by ‘Candidatus Phytoplasma solani’ in the Republic of Macedonia

“…East and causes serious economic losses in grapevine production (Johannesen et al 2012;Aryan et al 2014;Cvrković et al 2014).…”

“…The documented vectors that transmit 'Ca. P. solani' to grapevines are polyphagous planthoppers of xerothermic habitats, namely Hyalesthes obsoletus and Reptalus panzeri, both of which belong to the Cixiidae family (Maixner 1994;Cvrković et al 2014). Nevertheless, other species such as R. quinquecostatus and Anaceratagallia ribauti are also known to harbor 'Ca.…”

“…P. solani' consists of two genetically divergent strain types, tuf-a and tuf-b, which are involved in the two diverse epidemiological cycles of BN (Langer and Maixner 2004). The tuf-b type is primarily associated with field bindweed (Convolvulus arvensis), the major host plant of H. obsoletus in the eastern and southeastern occurrences of the disease (Langer and Maixner 2004;Johannesen et al 2012), although it infects a number of diverse weedy plants ( Riedle-Bauer et al 2008;Johannesen et al 2012;Cvrković et al 2014). Tuf-a strains of 'Ca.…”

Statistical modeling of long-term grapevine response to ‘Candidatus Phytoplasma solani’ infection in the field

“…In Europe, 'Candidatus Phytoplasma solani' from the stolbur group 16 SrXII-A (Quaglino et al 2013), which causes bois noir (BN) disease, is the most widespread and may lead to up to 50% loss of grape clusters (Starý et al 2013). BN is usually endemic in the Euro-Mediterranean area, and its spread occurs via a complicated disease cycle which includes insect vectors and multiple herbaceous plants as phytoplasma reservoirs (Belli et al 2010;Cvrković et al 2014).…”

Using Bayesian Inference to Investigate the Influence of Environmental Factors on a Phytoplasma Disease

“…Complexity is linked to many sources of uncertainty which in most cases are difficult to measure. Among others, these sources of uncertainty include vector-pathogen-plant interactions, but also the presence of unknown vectors (e.g., Reptalus panzeri was recently confirmed as a new vector in the grapevine phytoplasma disease "bois noir" [3]) or the time (i.e., latent period) between pathogen infection and symptom expression (in case of plants) or the ability to retransmit the pathogen (in case of vectors).…”