Submitted to: North American Strawberry Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 7, 2001
Publication Date: N/A
Interpretive Summary: Phytoplasmas are bacteria-like organisms that infect many plants and often cause serious crop losses. Strawberry plants also can be infected with phytoplasmas, causing fruit losses as well as plant death. It has been only recently that research has focused on identifying and characterizing phytoplasmas from commercial strawberry and associating their presence with disease symptoms. By analyzing genes of phytoplasmas detected in diseased strawberry plants, we found several new phytoplasmas are associated with diseases of strawberry and determined that disease symptoms in strawberry plants may not be characteristic of a particular phytoplasma. For example, deformations of fruit, called phyllody, in which leafy growths develop from the fruit, can be associated with any of several different phytoplasmas. This information will benefit scientists concerned with identification and control of strawberry diseases and effects of phytoplasma infection in plants other than strawberry.
Technical Abstract: In a recent series of studies we have determined that several newly detected and distinct phytoplasmas are associated with disease of strawberry (Fragaria x ananassa Duch.) fruit: strawberry multicipita (MC)(16S rRNA group VI, subgroup B), STRAWB2 (16S rRNA group I, subgroup K), clover yellow edge(16S rRNA group III, subgroup B), clover proliferation(16S rRNA group VI, subgroup A), and strawberry leafy fruit (SLF)(16S rRNA group III, subgroup K) phytoplasmas. Symptom expression was not closely correlated with the identities of phytoplasmas detected. The MC phytoplasma was detected in plants exhibiting crown proliferation in addition to stunting and phylloid fruit, whereas SLF and STRAWB2 phytoplasmas were detected in plants exhibiting chlorosis in addition to stunting and fruit phyllody. It seems apparent that strawberry can be host to many distinct phytoplasmas and that symptom expression associated with phytoplasma infection is neither characteristic of particular phytoplasmas nor of 16S rRNA phylogenetic groups of phytoplasmas.