Phytoplasmas are cell wall-less plant-pathogenic bacteria that inhabit the phloem of infected plants.

They are transferred by phloem feeding insect vectors (1) or by vegetative propagation of infected plants, and can infect more than 700 plant species (2), including many economically important crops. In wild and cultivated Rubus species like raspberry (Rubus ideaeus L.), blackberry (Rubus fruticosus L.), loganberry (Rubus x loganobaccus), and European dewberry (Rubus caesius L.) they cause a disease referred to as Rubus stunt. Symptoms include stunted growth, shoot proliferation, small leaves, short internodes, enlarged sepals, phyllody, flower proliferation, as well as fruit malformations (3).

This assay now provides a practical tool for the screening of motherplants and monitoring the presence and distribution of phytoplasmas in Rubus plants of different geographic origins, cultivars, and cultivation systems, as well as in putative insect vectors like leafhoppers (4).

The multiplex qPCR TaqMan assay developed in this interesting study will now allow a quick and reliable identification of phytoplasma insect vectors in orchards. Since measurements targeting insect vectors of phytoplasmas are the only options for managing phytoplasmas and particularly for preventing their spread within and among orchards, a detailed knowledge of respective vectors is a prerequisite for improvement of plant protection strategies against phytoplasma diseases (5).

References_____________________________

(1) Weintraub PG, Beanland L
Annu Rev Entomol. 2006; 51():91-111.

(2) Hoshi A, Ishii Y, Kakizawa S, Oshima K, Namba S. Host-parasite interaction of phytoplasmas from a molecular biological perspective. Bull Insectology. 2007;60: 105–107

(3) Mäurer R, Seemüller E. Nature and genetic relatedness of the mycoplasma-like organism causing Rubus stunt in Europe. Plant Pathol. 1994;44: 244–249

(4) A multiplex TaqMan qPCR assay for sensitive and rapid detection of phytoplasmas infecting Rubus species.
Linck H, Krüger E, Reineke A.
PLoS One. 2017 May 17;12(5):e0177808. doi: 10.1371/journal.pone.0177808. eCollection 2017.

(5) A multiplex TaqMan qPCR assay for sensitive and rapid detection of phytoplasmas infecting Rubus species.
Linck H, Krüger E, Reineke A.
PLoS One. 2017 May 17;12(5):e0177808. doi: 10.1371/journal.pone.0177808. eCollection 2017.