DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.

Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.

Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial blight
HOST: Anthurium
Leaf with necrotic lesions surrounded by chlorotic zones, indicative of stomatal invasion.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Anthurium
Chlorosis of leaf margins, an early stage of disease.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Anthurium
Necrotic lesions surrounded by chlorotic zones, indicative of hydathode invasion.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima
DISEASE: Bacterial blight
HOST: Anthurium
Leaves with necrotic margins.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima
DISEASE: Bacterial blight
HOST: Anthurium
Chlorotic leaf with signs of water stress caused by infection of vascular system.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima
DISEASE: Bacterial blight
HOST: Anthurium
Sliced petiole with discolored cortical tissues, indicative of systemic infection.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima