Pathogen tests for nuclear stocks - Fragaria

Plants for testing are assessed in aphid-proof glasshouses for the following pathogens, prior to long term maintenance in a glasshouse under ‘high health’ conditions where plants are regularly re-checked for these pathogens.

Viruses detectable by mechanical inoculation of sap to test plants, including: Arabis mosaic virus, Fragaria chiloensis virus, Raspberry ringspot virus, Strawberry latent ringspot virus, Strawberry mottle virus, Tobacco ringspot virus, Tobacco streak virus, Tobacco necrosis virus, Tomato black ring virus and Tomato ringspot virus.

Pathogens detectable by graft inoculation when using Fragaria indicators, UC6 (F. vesca x F. virginiana hybrid) and UC5 (a complex hybrid of F. vesca, F. chiloensis and F. virginiana) and UC 11 (F. virginiana). Pathogens detected include: Strawberry crinkle virus, Strawberry mild yellow-edge virus, Strawberry mild yellow-edge associated virus, Strawberry pseudo-mild yellow edge virus, Strawberry mottle virus, and Strawberry vein banding virus, Strawberry lethal decline phytoplasma, and the causal agents of Strawberry feather-leaf, Strawberry pallidosis, Strawberry latent C, Strawberry leafroll, Strawberry chlorotic fleck diseases and Tomato ringspot virus.

Symptoms of: June yellows and symptoms induced by Aster yellows, Strawberry green petal disease, Strawberry multiplier disease, Strawberry mycoplasma yellows and Strawberry witches' broom phytoplasmas, Strawberry marginal chlorosis disease and Strawberry rickettsia yellows bacterium-like organisms and Strawberry vein banding virus.

Fungal testing for Strawberry red core (Phytophthora fragariae var. fragariae) and Strawberry crown rot (Phytophthora cactorum) by nested PCR, and Strawberry blackspot (Colletotrichum acutatum) by the Paraquat test.

Testing for leaf and stem nematodes (Ditylenchus dipsaci, Aphelenchoides fragariae, A. ritzemabosi) by the Baermann technique.