Browsing by Author "Michel Dollet"

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    Characterization of the genetic diversity of the Tall coconut (Cocos nucifera L.) in the Dominican Republic using microsatellite (SSR) markers
    (2009) Reina Teresa Martinez; Luc Baudouin; Angelique Berger; Michel Dollet
    The predominant coconut variety cultivated in the Dominican Republic is a local Tall, known as criollo. It was never characterized genetically. The Malayan Dwarf and its hybrid with the local Tall are also present. Thirteen accessions, representing nine localities, are planted in a collection at the Instituto Dominicano de Investigaciones Agropecuarias y Forestales (IDIAF). We explored genetic diversity in 114 individuals from this collection. The main aim was to detect possible relationship with resistant varieties to coconut lethal yellowing (LY) disease. Contrarily to what happened in other Caribbean countries, LY never became an epidemic in the Dominican Republic. Thirteen simple sequence repeats markers from a kit dedicated to coconut diversity were used. In addition to diversity parameters, we used Bayesian assignment tests and cluster analysis to determine its population structure and its relationship with other coconut populations. The criollo coconut proved to be a typical Indo-Atlantic variety and is probably highly susceptible to the usual LY pathogens. Local conditions and the nature of the local phytoplasma strain probably explain the particular epidemiology of LY in the Dominican Republic. As a crosspollinating variety, the criollo presents polymorphism within a population, but there is little if any variation among populations. The marker study confirmed the hybrid status of each member of two accessions and, thus, the reliability of the sampling
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    Kinetoplast DNA minicircles of phloem-restricted Phytomonas associated with wilt diseases of coconut and oil palms have a two-domain structure
    (Elsevier Science, 2001) Michel Dollet; Nancy R. Sturm; Jean-Charles Ahomadegbe; David A. Campbell
    We report the cloning and sequencing of the first minicircle from a phloem-restricted, pathogenic Phytomonas sp. (Hart 1) isolated from a coconut palm with hartrot disease. The minicircle possessed a two domain structure of two conserved regions, each containing three conserved sequence blocks (CSB). Based on the sequence around CSB 3 from Hart I, PCR primers were designed to allow specific amplification of Phytomonas minicircles. This primer pair demonstrated specificity for at least six groups of plant trypanosomatids and did not amplify from insect trypanosomatids. The PCR results were consistent with a two-domain structure for other plant trypanosomatids.
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    The Panama Tall and the Maypan hybrid coconut in Jamaica: did genetic contamination cause a loss of resistance to Lethal Yellowing?
    (2008) Angelique Berger; Patricia Lebrun; Luc Baudouin; Wayne Myrie; Michel Dollet; Basil Been
    We applied Bayesian population assignment methods to assess the trueness to type of four populations of the coconut cultivar Panama Tall (PNT) located in Jamaica and found that two of them presented a high percentage of oV-types, while genetic contamination was low in the two others. The PNT is the pollen parent of the MAYPAN hybrid, which used to be planted in Jamaica to control an epidemic disease: Lethal Yellowing. The main source of contamination was the susceptible Jamaica Tall, thus increasing the susceptibility in the resulting MAYPAN progeny. The incidence of genetic contamination seems however to be insuYcient to be the only cause of the latest outbreak of the disease. Neither the MAYPAN nor its parents can be said resistant in the present context of Jamaica.
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    Search for the vector of Cape Saint Paul wilt (coconut lethal yellowing) in Ghana
    (2007) Rene PHILIPPE; Joe Pokou NKANSAH; Sandrine FABRE; Robert QUAICOE; Fabian PILET; Michel Dollet
    Phytoplasmas are associated to coconut lethal yellowing disease in several tropical and sub-tropical areas of the world and many coconut palms have been destroyed by this disease. A report of more than 15 years of search to detect insect vector(s) of coconut lethal yellowing disease (Cape Saint Paul wilt - CSPW) in Ghana is presented.