Papers by Frédéric Breton
Basal stem rot caused by Ganoderma boninense is the major threat to oil palm cultivation in South... more Basal stem rot caused by Ganoderma boninense is the major threat to oil palm cultivation in South-East Asia, which accounts for 80% of palm oil production worldwide, and this disease is increasing in Africa. The use of resistant planting material as part of an integrated pest management of this disease is one sustainable solution. However, breeding for Ganoderma resistance requires long-term and costly research, which could greatly benefit from marker assisted selection (MAS). In this study, we evaluated the effectiveness of an in silico genetic mapping approach that took advantage of extensive data recorded in an ongoing breeding program. A pedigree-based QTL mapping approach applied to more than 10 years’ worth of data collected during pre-nursery tests revealed the quantitative nature of Ganoderma resistance and identified underlying loci segregating in genetic diversity that is directly relevant for the breeding program supporting the study. To assess the consistency of QTL effe...
Genetic resistance to basal stem rot (BSR) of oil palm is an important component of an integrated... more Genetic resistance to basal stem rot (BSR) of oil palm is an important component of an integrated disease control strategy. Early detection of susceptibility or resistance level is essential for a breeding program and for the sustainability of this crop, particularly in Southeast Asia. A screening test for oil palm progenies was developed and validated using planting material from two private companies in Indonesia, PT PP London Sumatra Indonesia (Lonsum) and PT Socfin Indonesia (Socfindo) -. The first symptoms of the disease appeared between 8 and 10 weeks after inoculation of germinated seeds. The analysis of the crosses tested showed a positive correlation between 16 and 28 weeks, indicating that early detection is realistic and that there is minimal interaction of the susceptibility to the disease over time. The main objective of this paper is to highlight the efficiency and reproducibility of this early pre-nursery inoculation test to detect approximately 100 progeny per month.
DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucle... more DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res. 25:3389-402. FAO (2013) FAOSTAT, http://faostat3.fao.org/home/index.html#HOME. 31/01/2013. Gardes M, Bruns T (1993) ITS primers with enhanced specificity for Basidiomycetes-application to the identification of mycorrhizae and rusts. Mol. Ecol. 2:113-118. Guerin-Laguette A, Conventi S, Ruiz G, Plassard C, Mousain D (2003) The ectomycorrhizal symbiosis between Lactarius deliciosus and Pinus sylvestris in forest soil samples: symbiotic efficiency and development on roots of a rDNA internal transcribed spacer-selected isolate of L. deliciosus. Mycorrhiza 13:17-25. Lecellier G, Silar P (1994) Rapid methods for nucleic acids extraction from Petri dish-grown mycelia. Current Genetics 25:122-123. Martin F, Diez J, Dell B, Delaruelle C (2002) Phylogeography of the ectomycorrhizal Pisolithus species as inferred from nuclear ribosomal DNA ITS sequences. New Phytol. 153:345-357. Mitche...
Plant Molecular Biology Reporter, 2003
Abstract We developed a hydroponic cultivation system for growingArabidopsis plantlets under ster... more Abstract We developed a hydroponic cultivation system for growingArabidopsis plantlets under sterile, controlled environmental conditions. The system consists of a piece of stainless-steel wire cloth (125 μm mesh size) that is fixed between 2 flat rings and held in ...
Journal of Molecular Biology, 2007
Journal of Chromatography B, 2007
Cassiicolin, a phytotoxin produced by the necrotrophic fungus Corynespora cassiicola, was purifie... more Cassiicolin, a phytotoxin produced by the necrotrophic fungus Corynespora cassiicola, was purified to homogeneity from a rubber tree isolate. The optimized protocol involves reverse phase chromatography followed by size exclusion chromatography, with monitoring of the toxicity on detached rubber tree leaves. Cassiicolin appeared to be a peptide composed of 27 amino acids, glycosylated on the second residue, with a N-terminal pyroglutamic acid and 6 cysteines involved in disulfide bonds. Its molecular mass was estimated to be 2885 Da. No significant sequence homology with other proteins could be found. The availability of pure toxin in sufficient amount is a prerequisite for its structure determination, which is a key step in the understanding of the aggression mechanism.
Fungal Biology, 2014
Corynespora cassiicola is an important plant pathogenic Ascomycete causing the damaging Corynespo... more Corynespora cassiicola is an important plant pathogenic Ascomycete causing the damaging Corynespora Leaf Fall (CLF) disease in rubber tree (Hevea brasiliensis). A small secreted glycoprotein named cassiicolin was previously described as an important effector of C. cassiicola. In this study, the diversity of the cassiicolin-encoding gene was analysed in C. cassiicola isolates sampled from various hosts and geographical origins. A cassiicolin gene was detected in 47 % of the isolates, encoding up to six distinct protein isoforms. In three isolates, two gene variants encoding cassiicolin isoforms Cas2 and Cas6 were found in the same isolate. A phylogenetic tree based on four combined loci and elucidating the diversity of the whole collection was strongly structured by the toxin class, as defined by the cassiicolin isoform. The isolates carrying the Cas1 gene (toxin class Cas1), all grouped in the same highly supported clade, were found the most aggressive on two rubber tree cultivars. Some isolates in which no Cas gene was detected could nevertheless generate moderate symptoms, suggesting the existence of other yet uncharacterized effectors. This study provides a useful base for future studies of C. cassiicola population biology and epidemiological surveys in various host plants.
Acta Botanica Gallica, 1996
Des inoculations in vitro de folioles d'hevea par des gouttes de suspension de spores d'i... more Des inoculations in vitro de folioles d'hevea par des gouttes de suspension de spores d'isolats de Corynespora ou leurs pulverisations in planta montrent des differences de resistance-sensibilite (R/S) chez les clones testes. Cette R/S varie selon l'isolat, la densite des spores, l'etat physiologique de l'arbre, l'intensite lumineuse, etc. PB 260 est tres sensible, GT 1 est presque totalement resistant, dans nos conditions. L'excretion d'une toxine, isolee et identifiee comme un glycopeptide de faible masse moleculaire, dans le milieu de culture de Corynespora, ou dans le fluide de germination des spores, a ete confirmee. L'utilisation de ces 2 milieux conduit au meme classement R/S des 9 clones etudies que l'inoculation par des spores. La sensibilite d'un clone d'hevea dependrait de son aptitude a reconnaitre cette toxine et/ou de sa capacite a la neutraliser. L'emploi de cette toxine en application foliaire ponctuelle conduirait ...
Des inoculations in vitro de folioles d'hevea par des gouttes de suspension de spores d'i... more Des inoculations in vitro de folioles d'hevea par des gouttes de suspension de spores d'isolats de Corynespora ou leurs pulverisations in planta montrent des differences de resistance-sensibilite (R/S) chez les clones testes. Cette R/S varie selon l'isolat, la densite des spores, l'etat physiologique de l'arbre, l'intensite lumineuse, etc. PB 260 est tres sensible, GT 1 est presque totalement resistant, dans nos conditions. L'excretion d'une toxine, isolee et identifiee comme un glycopeptide de faible masse moleculaire, dans le milieu de culture de Corynespora, ou dans le fluide de germination des spores, a ete confirmee. L'utilisation de ces 2 milieux conduit au meme classement R/S des 9 clones etudies que l'inoculation par des spores. La sensibilite d'un clone d'hevea dependrait de son aptitude a reconnaitre cette toxine et/ou de sa capacite a la neutraliser. L'emploi de cette toxine en application foliaire ponctuelle conduirait ...
Early detection of the level of resistance or susceptibility to Ganoderma boninense is of paramou... more Early detection of the level of resistance or susceptibility to Ganoderma boninense is of paramount importance for the sustainability of the oil palm industry particularly in South-East Asia. A nursery Ganoderma screening method has been developed and validated in collaboration with two Indonesian private companies PT PP London Sumatra Indonesia TBK (Lonsum) and PT Socfin Indonesia (Socfindo) to improve the resistance of their commercial planting material to Basal Stem Rot (BSR) disease. This early routine prenursery screening test involves the exposure of germinated seeds from different oil palm progenies with Ganoderma-colonized Rubber Wood Blocks (RWBs). Over the last two years, the potential testing capacities have been developed in both companies to allow the routine screening work of one hundred crosses per month. Currently, more than 1000 crosses have been tested at least two times in independent trials for their resistance/susceptibility level to Ganoderma. The screening met...
Indonesia recently pledged to become a major global food producer by boosting the production of f... more Indonesia recently pledged to become a major global food producer by boosting the production of food commodities. Palm oil is one of the 10 strategic and key commodities that are part of the government's 2009 - 2014 road-map for food development. Domestic palm oil producers are being encouraged to expand their plantations from the current 7.9 million hectares in 2009 to 9.7 million hectares by 2015. Indonesia goal is to boost CPO production to 36.6 million tonnes per year (Maulia, 2010). The apparent stagnation of long term palm oil yield trends in the dominant producing countries, such as Malaysia and Indonesia, is considered a vital concern for the oil palm industry and this new agenda makes the intensification of plantation efficiency more necessary, in the context of sustainable palm oil production. Planting material quality has been recognised as a key input for oil palm sustainability. Where the technical efficiency of growers in all the best management practices (BMPs) is...
The existence of a high lignified star-shaped cavity at the base of the bole, or more precisely a... more The existence of a high lignified star-shaped cavity at the base of the bole, or more precisely at the root - bole interface, has been clearly identified for the first time. This cavity appears to be a perfect culture chamber for Ganoderma development. Random observations of the initial stage of Basal Stem Rot infection in young palms showed the development of infectious stroma-like structures inside the cavity prior to colonisation of the bole. The existence of a lignified scar in 8-month-old seedlings was revealed by initial observation. The scar then developed further inside the star-shaped cavity (Breton et al, 2009a; Breton et al, 2009b). Specific observation during early growth stages in the nursery revealed the appearance of a very tiny scar after 5 months on a few seedlings. The number of affected seedlings increased rapidly to reach nearly 100% after 9 months. The scar grew quickly in all directions and the resulting cavity could reach 50% of bole diameter, 13 mm wide and 8...
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Papers by Frédéric Breton