Submitted to: Phytopathology
Publication Type: Abstract only
Publication Acceptance Date: 5/10/2002
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: A disease appearing similar to elm yellows (EY) has killed over 1000 American elm trees during the last decade in the Chicago metropolitan area. Irregular symptoms and negative detection test results led us to sample trees during 1998-2000 for EY phytoplasma. Nested PCR using universal primer pairs revealed that 14 of 15 trees sampled had phytoplasma and although they expressed a range of symptoms, all died within two years. Ten asymptomatic control elms tested negative. Phloem scraped from bark was superior to wood shavings or foliage for detecting phytoplasma. RFLPs and DNA sequencing of 16S rDNA indicated that the Illinois phytoplasma is not related to the EY phytoplasma group, but instead is a new member of the clover proliferation phytoplasma group (16SrVI). Neither EY nor the newly designated Illinois elm yellow (ILEY) phytoplasma was detected in leafhopper samples trapped from elms daily between May and September, 2000.