hosted by the Molecular
Plant
Pathology Laboratory (MPPL)
Glossary; symptoms
Plants infected by phytoplasmas may exhibit one or more of the following symptoms:
Phyllody - development of leaf-like growths in place of normal flower parts (image 1)
(image 2)
Virescence - development of green color in place of normal flower color
(image 1)
Witches broom - abnormal, excessive proliferation of axillary shoots resulting in a
broom-like growth (image 1)
Yellowing - leaves loose normal green color, becoming yellow (image 1)
Little leaf - development of abnormally small leaves (image 1)
Proliferation - abnormal growth of numerous stems (shoots)
(image 1)
Necrosis - death of cells and/or tissues
Dieback - generally refers to death of branches on woody plants, shrubs, trees;
typically, young shoots, twigs, and distal portions of branches die
progressively toward older plant parts
Stunting - overall reduction of plant height due to shortening of internod
Bunchy top - shortening of internodes at and near the tip of a branch,
resulting in bunched growth at the end of the branch
Dr. Robert E. Davis, Research Leader
United States Department of Agriculture Building 004, BARC-West
10300 Baltimore Ave. Beltsville, MD. 20705
Designed and created by Jonathan Shao, shaoj@ba.ars.usda.gov