Search for alternate hosts of the coconut Cape Saint Paul wilt disease pathogen
Loading...
Date
2009-08-23
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Lethal yellowing disease, locally called Cape St. Paul Wilt disease (CSPWD), is the bane of the coconut industry in Ghana and is caused by a phytoplasma. Phytoplasmas are 'cell wall-less' prokaryotes belonging to the class Mollicutes. In Ghana, there are areas where the disease has resurged after a long period of dormancy. This brings »to fore the possibility of alternate hosts in the spread of the disease since the pathogen is an obligate parasite. The identification of alternate hosts will increase our understanding of the spread of the disease and help evolve sound integrated control measures against the spread of the disease. In this work fifty seven plant species sampled from Cape Three Points in the Western Region and Asebu in the Central Region were screened for their host status to the CSPWD pathogen. The presence of phytoplasmas in these plants was tested by polymerase chain reaction (PCR) analyses using universal phytoplasma primer pair P1/P7 which identifies phytoplasmas of all types. A further test was carried out with CSPWD specific primer pair G813/GAKSR to verify the positives detected by the 'universal primers'. To confirm the PCR results, Restriction Fragment Length Polymorphism (RFLP) analysis was performed on samples which tested positive to the CSPWD specific primers. Whilst several species tested positive with the universal primers, only Desmodium adscendens samples tested positive with the CSPWD specific primers. RFLP analyses with EcoRl and Hind III produced patterns consistent with the profile of the CSPWD phytoplasma, but Rsa 1 and Alu 1 gave patterns different from the expected profile. Cloning and sequencing however failed to confirm the amplified organism as the CSPWD phytoplasma, but rather the organisms were found to be related
to Bacillus megateruim and Rhodobacter sphaeroides. It is therefore imperative to clone and sequence in molecular experiments before making conclusions.
Description
A thesis submitted to the Department of Biochemistry
and Biotechnology in partial fulfilment of the Requirements for the award of a Master of Science in Biotechnology, 2009