Browsing by Author "Luc Baudouin"

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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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    Coconut (Cocos nucifera L.) DNA studies support the hypothesis of an ancient Austronesian migration from Southeast Asia to America
    (2009) Luc Baudouin; Patricia Lebrun
    The centre of origin of coconut extends from Southwest Asia to Melanesia. Nevertheless, its pre-Columbian existence on the Pacific coast of America is attested. This raises questions about how, when and from where coconut reached America. Our molecular marker study relates the pre-Columbian coconuts to coconuts from the Philippines rather than to those of any other Pacific region, especially Polynesia. Such an origin rules out the possibility of natural dissemination by the sea currents. Our findings corroborate the interpretation of a complex of artefacts found in the Bahı´a de Caraquez (Ecuador) as related to South-East Asian cultures. Coconut thus appears to have been brought by Austronesian seafarers from the Philippines to Ecuador about 2,250 years BP. We discuss the implications of molecular evidence for assessing the possible contribution of early trans-pacific travels to and from America to the dissemination of domesticated plants and animals
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    Coconut Palms on the Edge of the Desert:Genetic Diversity of Cocos nucifera L. in Oman
    (2011) Lalith Perera; Luc Baudouin; Roland Bourdeix; Anwar Bait Fadhil; Fabien C.C.Hountondji; Abdulaziz Al-Shanfri
    In the Gulf region, coconuts are almost exclusively produced from palms growing in the Sultanate of Oman, particularly in the extreme south-eastern coastal plain of the Dhofar Governorate,and specifically within the city limits of Salalah, between the Jebel and the sea. The importance of these coconuts is not only agricultural; historically, the Dhofar palms provided the basic materials to build boats for fishermen and traders on, around and eventually beyond the Indian Ocean. Coconut palms are now one of the main symbols of Salalah city and playa role in both the tourist industry and urban landscaping. In early 2009, twenty-nine sites, representing Oman coconuts on beaches and cultivated lands were chosen from the Dhofar region.COGENT descriptors and DNA analysis were used for the purpose of identifying coconut germplasm available in Oman. The presence was confirmed of varieties that were imported during the 1980s, such as Yellow Dwarf, Green Dwarf and King coconut from Sri Lanka, as well as Malayan Yellow Dwarf and Fl hybrids. The local Oman Tall has the same phenotypic characteristics as other coconuts of South Asia, East and West Africa,the Caribbean and the Atlantic coast of South America. Microsatellite markers, however, reveal a substantial genetic contribution of the South-East Asian coconuts, at levels that are comparable to those found in the Comoros and Madagascar coconuts. Hypotheses about the ancestry of the Oman Tall coconuts are discussed; two genepools are indicated, consecutively involving natural selection, dissemination by floating, domestic selection and dispersal by boat.
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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.