Title: Identification of lethal yellowing group (16SrIV) of phytoplasmas in the weeds Stachytarpheta jamaicensis, Macroptilium lathyroides and Cleome rutidosperma in Jamaica
Abstract: A survey was conducted to identify weed hosts of the lethal yellowing phytoplasma in areas that had high (St Thomas and Portland) as well as low incidences (St Mary and St Elizabeth) of the disease. More than 600 weed samples representing 46 species in 23 families were collected from 30 field sites over a 16 month period. Coconut lethal yellowing phytoplasma was detected in samples of the weeds Cleome rutidosperma, Macroptilium lathyroides and Stachytarpheta jamaicensis in all the places tested in Jamaica by nested polymerase chain reaction (PCR) assay employing the 16SrRNA primer pairs P1/P7 and LY16Sf/LY16Sr. A 1,400-bp product was obtained from 21 out of 35 S. jamaicensis, 26 out of 75 C. rutidosperma and 29 out of 89 M. lathyroides weeds analyzed. Restriction fragment length polymorphism (RFLP) analyses of nested PCR products using the enzymes AluI, MspI and Tru9I revealed that there are different RFLP variants of the LY phytoplasma infecting the weeds S. jamaicensis, M. lathyroides and C. rutidosperma. The weed infecting phytoplasma strains could be classified tentatively as members of the lethal yellowing (LY) phytoplasma (16SrIV-E) group. All the LY16Sf/LY16Sr sequences from the three weed species were approximately 98% identical to that of the phytoplasma strains in Floridsa (LYFL-C2) and Jamaica (LYJ-C8). The LY phytoplasmas found in the three weeds analyzed clustered together with previously characterized strains within the lethal yellowing phytoplasma (16SrIV) group. [Brown, S.E. & McLaughlin W.A. (2011). Identification of lethal yellowing group (16SrIV) of phytoplasmas in the weeds Stachytarpheta jamaicensis, Macroptilium lathyroides and Cleome rutidosperma in Jamaica. Phytopathogenic Mollicutes, 1(1), n.p]