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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #272933
Title: A quantitative PCR assay for the detection of phytoplasmas causing almond brownline, peach yellow leafroll, and pear decline diseases in California

Author
item Sudarshana, Mysore
item Gonzalez, Asaul
item Dave, Ashita
item Uyemoto, Jerry

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2011
Publication Date: 8/15/2011
Citation: Sudarshana, M.R., Gonzalez, A., Dave, A.M., Uyemoto, J.K. 2011. A quantitative PCR assay for the detection of phytoplasmas causing almond brownline, peach yellow leafroll, and pear decline diseases in California. Phytopathology. 101:S172.

Interpretive Summary:

Technical Abstract: Phytoplasmas cause several important diseases in California’s almond and fruit tree orchards. A phytoplasma associated with almond brown line (ABL) disease, peach yellow leafroll phytoplasma (PYLR-P) and pear decline phytoplasma (PD-P) are genetically related based on homology in the 16S-23S rDNA spacer region. In an attempt to detect these three phytoplasmas, a primer pair was designed to amplify a 530-bp product from the 16S-23S rDNA spacer region. Using this primer pair and SYBR Green, a quantitative PCR (qPCR) assay was developed to facilitate detection and analysis from multiple samples. A detection limit of 100 copies was achieved in assays using nucleic acid extracts from almond leaves spiked with cloned target DNA from PYLR-P. The qPCR assay detected PYLR-P in almond and peach trees, PD-phytoplasma in pear trees, but not a genetically different X-disease phytoplasma in cherry trees. This new assay was also able to detect PYLR-phytoplasma in dormant peach buds from infected trees and is expected to aid in the detection and amplification of ABL-P, PYLR-P and PD-P in almond, peach and pear trees, respectively.