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Last modified: 4 December 2005

Contacts or sources of information - DICTA, FHIA, Zamorano

Occurrence - LY was detected on the Bay Island of Roatan in early 1996 and later in the same year at Santa Fe near Trujillo (Colón) on the mainland. Identification was confirmed by PCR analysis (Ashburner et al, 1996).

Spread - By mid 1997 the disease had spread and appeared at Sambo Creek, Corozal and Cuyamel, near La Ceiba, and Punta Sal and Tornabé, near Tela (Atlántida).

Currently active areas - As of April 1999 the disease had spread eastwards to Santa Rosa de Aguan (Colón) and westwards to Playa del Miami and Rio Tinto (Atlántida) and Saraguiana, Bajamar and Travasia (Cortés). The rate of spread in Cortés and between Tela and El Progreso (Atlántida) may be affected by the large numbers of Malayan Dwarf (mainly reds) planted domestically (there and also sporadically elsewhere)some thirty years ago. By June 2001 LY had destroyed up to 90% of the susceptible Atlantic Tall variety on the Atlantic coast and was reported recently inland on Lago Yojoa, but not in Choluteca on the Pacific Coast.

Suspected new outbreaks - specify whether confirmed or unconfirmed (reference)

Other palm/plant hosts

New hosts, new vectors, new strains or suspected loss of resistance - Myndus crudus and Myndus simplicatus were found quite readily on young palms in coconut nurseries (although neither are yet confirmed as vectors in Honduras).

Research projects - A collaboration with the University of Florida was undertaken to compare coconut LY phytoplasma strains in the region by RFLP analysis of PCR-amplified ribosomal RNA gene sequences. This work revealed that the molecular profiles of LY phytoplasmas from Honduras mostly conformed to those associated with ‘typical’ cases of LY disease in Florida, Belize and Mexico. However, the uniform rDNA RFLP patterns of Jamaican LY phytoplasmas clearly differed from those of ‘typical’ LY phytoplasmas from the other localities. Differences were detected only after HinfI endonuclease digestion of PCR products. Resulting rDNA restriction patterns indicated the presence of two heterogeneous rRNA operons ( i.e. rRNA-a and rRNA-b) in Florida, Belize and Mexico LY phytoplasmas. Patterns characteristic of Jamaican LY phytoplasmas suggested that these strains uniformly possessed either one rRNA operon (rRNA-a) only or, alternatively, two sequence-identical operons. One of the 18 LY phytoplasma samples analyzed in detail from Honduras gave a HinfI restriction pattern conforming to one operon (rRNA-b) only. Further support was obtained by cloning and sequencing each putative rRNA operon.

In studies undertaken on the coconut plantation at Salado Lislis, where leaf yellowing and a high mortality in Maypan hybrids has previously been attributed to LY, the LY phytoplasma could only be detected in 25% of inflorescences tested from symptomatic palms and only 5% of trunk tissue from the same MAPAN hybrids. The plantation has been subject to inundation by sea water (as a result of hurricane Mitch) followed by unusually wet seasons suggesting that these may have significantly contributed to the decline. The result of the phytoplasma tests (25% of inflorescence positive compared with 5% of trunk tissue from the same palms) suggests that in these hybrids, PCR testing is more sensitive in tissue taken from the inflorescence than from the trunk.

Rehabilitation/replanting programmes

Economic importance/threat

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