Insect Vector and Reservoir Plant of ‘Fragaria × ananassa’ Phyllody Phytoplasma (16SrXIII-F) in Central Region of Chile

Abstract

Strawberry phyllody has emerged as a prevalent disease affecting Chilean strawberry in recent years. The causal pathogen, ‘Fragaria × ananassa’ phyllody phytoplasma (StrPh), is categorized within the 16S ribosomal group XIII, exclusively found in the Americas. In the context of economically significant crops, hemipteran insect vectors and alternative host plants play a pivotal role in their natural dissemination. This study comprehensively examined the key epidemiological facets of StrPh in the central region of Chile: the insect vector and alternative hosts. Through field surveys, we identified an abundance of an insect species, Cixiosoma sp., in an StrPh-infected strawberry field, and confirmed its role as a vector of this phytoplasma through subsequent transmission assays. Moreover, we found a spontaneous weed species, Galega officinalis, to be infected with StrPh, raising the possibility of it being a potential alternative host plant for this phytoplasma. StrPh was also detected in cold-stored strawberry runners purchased from a nursery that supplies the local strawberry cultivation, suggesting a potential source of this phytoplasma in Chile. Collectively, these findings provide a significant epidemiological source of StrPh dissemination in central Chile.