First report of the presence of the lethal yellowing group (16Sr IV) of phytoplasmas in the weeds Emelia fosbergii and Synedrella nodiflora in Jamaica
S.E. Brown1*, B.O. Been2 and W.A. McLaughlin1
1 Department of Basic Medical Sciences University of the West Indies Mona, Kingston 7 Jamaica
2 Coconut Industry Board, Waterloo Road, Kingston 10, Jamaica
Accepted for publication 22/08/07
Coconut lethal yellowing (CLY) disease is the single most important disease affecting coconuts in Jamaica. A study was conducted in 2005 to investigate alternate hosts of the CLY phytoplasma affecting coconuts. Weeds have been known to act as reservoir hosts of many plant pathogens. As a result, weeds growing in areas where coconuts are planted were tested for the presence of the CLY phytoplasma. The weeds Emelia fosbergii and Synedrella nodiflora (both Family Asteraceae) were collected at random from coconut farms in areas that had high as well as low incidences of CLY. None of the weeds were symptomatic. DNA from weed samples was extracted by the method of Dellaporta et al. (1993), while nucleic acid extraction from the reference coconut trunk sample (coconut plant infected with CLY) was done using the method of Doyle & Doyle (1990). Nested PCR was conducted using the primer pairs P1/P7 and LY16Sf/LY16S23r (Harrison et al., 2002a & 2002b).
A 1.6 kb amplicon was obtained from 9/51 E. fosbergiii plants tested and 4/36 S. nodiflora plants. The amplicons were compared by RFLP with the restriction endonucleases RsaI, MspI, MseI, TaqI, HinfI, AluI and HhaI to that of the CLY reference sample. Each pattern was identical to that of the reference sample (data not shown). Amplicons from E. fosbergii and S. nodiflora were cloned into pGEM®-T Easy cloning vector (Promega) and sequenced using the primers LY16Sf/LY16S23r at the Center for Functional Genomics (University of Albany, NY). Sequences were deposited in the GenBank (Assession No. EU026214 E. fosbergii and EU026213 S. nodiflora). Blast analysis of the rDNA sequences showed a 99% similarity to that of coconut lethal yellowing phytoplasma in Jamaica, Nevis and Florida (GenBank accession No. AF498301, DQ378279 and AF498309), members of the 16Sr IV group of phytoplasmas. This is the first report of the lethal yellowing (16Sr IV) group of phytoplasmas affecting the weeds E. fosbergii and S. nodiflora in Jamaica. Recognition of weeds as hosts of 16Sr IV group of phytoplasmas in Jamaica has epidemiological significance and suggests that weed control in and around coconuts may benefit disease management over the long term. It also lends credence to the possibility of the existence of another CLY vector other than Myndus crudus which has been known to feed only on monocotyledonous plants.
The authors would like to thank the Coconut Industry Board and the International foundation For Science (IFS) for funding this project.
Dellaporta SL, Wood J, Hicks JB, 1993. A plant minipreparation: Version II. Plant Molecular Biology Report 1, 19-21.
Doyle JJ, Doyle JL, 1990. Isolation of plant DNA from fresh tissue. Focus 12, 13-15.
Harrison NA, Myrie W, Jones P, Carpio ML, Castillo M, Doyle MM, Orpeza C, 2002a. 16S rRNA interoperon sequence heterogeneity distinguishes strain populations of palm lethal yellowing phytoplasma in the Caribbean region. Annals of Applied Biology 141, 183-193.
Harrison NA, NarvŠez M, Almeyda H, Cordova I, Carpio ML, Oropeza C, 2002b. First report of group 16Sr IV phytoplasmas infecting coconut palms with leaf yellowing symptomology on the pacific coast of Mexico. New Disease Reports [
The British Society for Plant Pathology