VectoRise

Inspiration

Global climate change significantly affects agro-environmental systems, especially multi-trophic systems, where alterations are observed, for example, in the interaction between host plants and their pathogens vectored by dedicated insect pests. Psyllids (Insecta, Hemiptera) are vectors that can transmit important plant pathogens called phytoplasmas.

Innovation

VectoRise aims to assess the ecological risks and regional specifications of an apple-psyllid-phytoplasma pathosystem under current and future climate conditions.

Cacopsylla melanoneura and Cacopsylla picta are considered the main insect vectors of ‘Candidatus Phytoplasma mali’, the causing agent of Apple Proliferation (AP). Both vectors acquire the phytoplasma by feeding on the phloem of infected plants. The natural infection rate and transmission capacity of both species are heterogeneous among the European regions. Wherever C. picta is present, it is considered the main vector (Northeast Italy, Germany), whereas C. melanoneura plays an important role only in Northwest Italy (Aosta Valley and Piedmont). Therefore, it has been hypothesized that the variation in C. melanoneura vector competence might be both linked to genetic differences among distinct populations and associated with different subtypes of ‘Ca. P. mali’.

For the first time, LIST researchers and the collaborating institutions will investigate factors that influence the acquisition dynamics of AP phytoplasma, including different geographic lineages. For this, they will survey the occurrence and abundance of C. melanoneura and its transmitted AP phytoplasma in Luxembourg and the Greater Region (Lorraine, Wallonia, Saar-Moselle region), as well as in Italy (South Tyrol and Aosta Valley) and Germany (Rhineland-Palatinate) to perform a comparative genomic study of the pathogen and the insect. The team will analyse the acquisition efficiency of different AP phytoplasma strains and genetic variants of C. melanoneura under laboratory conditions. Finally, they will investigate the response of this pathosystem to climate change based on climate chamber experiments.

Impact

The results of VectoRise will have direct consequences on the establishment of control strategies against the vectors of AP in the different countries studied and will help qualify current and future economic and ecological risks for apple production in Western Europe. The research is embedded in the strategy of the Agro-environmental system group at LIST, which aims to identify the effects of climate change on pathosystems with different trophic levels and support the development of non-chemical control strategies in resilient agricultural systems. The project will combine previous investigations in Luxembourg with ongoing studies in Germany, as well as results from South Tyrol describing regional differences in the acquisition of phytoplasma. It will contribute to the biodiversity studies conducted at the Musée national d'histoire naturelle (MNHNL) and will help to save orchards as national heritage sites of regional genetic sources in the Greater Region and beyond.

Photo: © Dr Wolfgang Jarausch - RLP AgroScience