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Phyllody on a purple coneflower (Echinacea purpurea). Phyllody is the abnormal development of floral parts into leafy structures. It is generally caused by phytoplasma or virus infections, [1] though it may also be because of environmental factors that result in an imbalance in plant hormones. [2]
Aster yellows is a chronic, systemic plant disease caused by several bacteria called phytoplasma. [1] The aster yellows phytoplasma (AYP) affects 300 species in 38 families of broad-leaf herbaceous plants, primarily in the aster family, and important cereal crops such as wheat and barley.
Virescence is the abnormal development of green pigmentation in plant parts that are not normally green, like shoots or flowers (in which case it is known as floral virescence). [1] Virescence is closely associated with phyllody (the abnormal development of flower parts into leaves ) and witch's broom (the abnormal growth of a dense mass of ...
Plant diseases are diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). [1] Organisms that cause infectious disease include fungi , oomycetes , bacteria , viruses , viroids , virus -like organisms, phytoplasmas , protozoa , nematodes and parasitic plants . [ 2 ]
Plants can show many signs or physical evidence of fungal, viral or bacterial infections. This can range from rusts or molds to not showing anything at all when a pathogen invades the plant (occurs in some viral diseases in plants). [9] Symptoms which are visible effects of diseases on the plant consist of changes in color, shape or function. [9]
Bacterial and viral infections can also cause fasciation. [4] The bacterial phytopathogen Rhodococcus fascians has been demonstrated as one cause of fasciation, such as in sweet pea ( Lathyrus odoratus ) plants, [ 7 ] and in lilies ( Lilium longiflorum ), [ 8 ] but many fasciated plants have tested negative for the bacteria in studies, [ 9 ...
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Given the lack of knowledge of human infectious diseases at this time (and well into the 19th century) this was not an unusual conclusion, [15] but what is surprising is that while tulip mosaic disease has a far more impressive and documented history than any other plant virus, the realization that it was a communicable plant disease, let alone ...