Papers by Dominique Dumet
Misidentification of accessions is a common problem in genebanks. Along the years, mistakes accum... more Misidentification of accessions is a common problem in genebanks. Along the years, mistakes accumulate and this is particularly true when dealing with a large number of accessions requiring annual regeneration. Human errors such as mislabeling or misreading and material mix up during planting or storage are the main causes for misidentification of accessions. The international collection of yam, maintained at IITA, has accumulated 'non true to type' accessions along the years. In the present study, 53 morphological descriptors were used to detect uniformity of individuals within accessions of the yam gene bank collection i.e. agro morphological mismatch between individual plants of the same accession. Based on a similarity matrix, individual pairs with less than 0.90 similarity coefficients, which varies in six descriptors and more, were considered as distinct and mismatched, whereas those that had similarity coefficients greater than or equal to 0.90 were considered as clones from the same parent. Overall, 20.60% of the total 3156 accessions were found not true to type i.e., misidentified individuals. The descriptive analysis shows that morphological traits like distance between lobes, upward folding of leaf along main vein, young stem color, old stem color, leaf shape, leaf density and plant vigor are the most discriminative descriptors for individual identification within accession. Some other traits were also found species specific and they may aid in distinguishing misidentifications between species.
Agricultural …, 2010
e Crop Genebank Knowledge Base (CGKB) is an initiative of the Consultative Group of Internationa... more e Crop Genebank Knowledge Base (CGKB) is an initiative of the Consultative Group of International Agriculture Research (CGIAR) System-wide Genetic Resources Programme (SGRP). e CGKB was created for sharing knowledge about best practices for managing plant genetic resources (PGR), and making effective decisions about genebank management. Genebank practices from CGIAR Centers and national genebanks were gathered for nine crops (banana, barley, cassava, chickpea, forage grasses and legumes, maize, rice and wheat). is information will help PGR professionals to participate in a global crop conservation effort. An interactive approach with many partners and stakeholders was used to gather published and unpublished information about genebank management. Information on crop-specific best practices was initially collected from crop experts using pre-defined forms. In parallel, a web portal was developed using the open-source content management system (CMS) Joomla!. e CMS allows several editors to maintain pages and update them. Other participatory tools such as wiki pages, a blog, a discussion forum and online forms have been set up to gather future contributions, including information on other crops. e site provides a one-stop platform for information on conservation, characterization, regeneration and safety duplication of each of the nine crops. It also provides information on general (non-crop-specific) genebank management procedures, as well as a comprehensive bibliography of online publications, a glossary, links to relevant external websites, video and photo materials, and training modules. is paper discusses a process of collective action to develop a multiinstitutional web platform, highlights important criteria for success, challenges and major lessons learned, and proposes options for the way forward.
Résumé. Un nouveau procédé de cryoconservation comprenant une étape de dessiccation au silicagel ... more Résumé. Un nouveau procédé de cryoconservation comprenant une étape de dessiccation au silicagel avant la congélation dans l’azote liquide a été développé pour les embryons somatiques standards de palmierà huile. II a été appliqué avec succès en France et en Côted‘Ivoire à 39 clones différents. La survie après cryoconservation a éré obtenue avec tous les clones, avec des taux variant entre 2 et 100%. Les clones ayant un aspect morphologique normal ont présenié un taux de survie significativement plus élevé (31% en moyenne) que ceux en mauvais état physiologique (12% en moyenne). La cryoconservation est maintenant appliquée en routine aux embryons somatiques de palmier àhuile avec ce procédé amélioré.
Cost information is useful to monitor the performance of the genebanks. Thus, managers, users, an... more Cost information is useful to monitor the performance of the genebanks. Thus, managers, users, and donors of the genebanks can have an idea of the relative costs of managing plant genetic resources. This information can be used to make users but especially donors aware of the actual costs of conserving and distributing accessions and in this way facilitate fund raising. Managers however do have an idea of genebank operational costs. What is then the added value of using a periodic system to collect costs information for the genebank manager? In this section we present some specific cases where the information collected in the genebanks visited can help in the decision process. It is true that the current amount of information does not allow us to make conclusions across centers, but it does allow for some analysis within the centers.....
![Research paper thumbnail of On the Dispersal of Bottle Gourd [Lagenaria siceraria (Mol.) Standl.] Out of Africa: a Contribution from the Analysis of Nuclear Ribosomal DNA Haplotypes, Divergent Paralogs and Variants of 5.8S Protein Sequences](https://attachments.academia-assets.com/104438705/thumbnails/1.jpg)
Plant Molecular Biology Reporter, 2015
Bottle gourd (Lagenaria siceraria), a multipurpose crop, is among the first domesticates of human... more Bottle gourd (Lagenaria siceraria), a multipurpose crop, is among the first domesticates of humans. This study analyses nuclear ribosomal DNA (nrDNA) of the two cultivated subspecies to improve our understanding on the African origin and the dispersal to Asia. A total of 146 nrDNA sequences representing 79 individuals from African cultivars and 67 individuals from Asian cultivars were compared; the resulting nrDNA sequences were composed of 35 and 16 haplotypes specific to Africa and Asia, respectively, and two additional haplotypes shared by both continents. When all the rDNA haplotypes were bulked, the genetic differentiation (F ST) was significant between the subspecies (P<0.001), within Africa (P < 0.001) and within Asia (P < 0.05), and the nucleotide diversity was 2.5-fold higher in Africa. Sorting the haplotypes by classes of paralogs revealed more classes in Africa, and in classes where African and Asian cultivars were represented, the diversity was higher in Africa, in general. The 5.8S-coding regions showed two to four amino acid differences resulting to nine protein sequence variants, one of which encompassed all the Asian cultivars. The nucleotide diversity at that shared variant was 1.43-fold higher in Africa than in Asia. Analyses of phylogenetic networks revealed major shared haplotypes containing 23.91 % of the cultivars and having founder locations. We suggest that African cultivars reached Asia. The study tags for the first time nrDNA haplotypes capable of discriminating between and within the subspecies. Thirty single nucleotide polymorphisms (SNPs) and five insertion-deletions (Indels) derived from the haplotypes and registered in GenBank are provided.
Meeting Abstracts of the Physical Society of Japan (Nihon Butsuri Gakkai koen gaiyoshu), 2011
African yam bean (Sphenostylis stenocarpa Hochst ex. A. Rich.) Harms is an underutilized tropical... more African yam bean (Sphenostylis stenocarpa Hochst ex. A. Rich.) Harms is an underutilized tropical African tuberous legume. It belongs to the class Magnoliopsida; order Fabales; family Fabaceae; subfamily Papilionoideaea; and genus Sphenostylis. There are seven species in the genus Sphenostylis (Potter and Doyle 1994). African yam bean (AYB) is the
Cryo letters, 2018
BACKGROUND: A cryopreservation protocol has been established for oil palm somatic embryos (SEs)... more BACKGROUND: A cryopreservation protocol has been established for oil palm somatic embryos (SEs), the efficiency of which must be evaluated, both in terms of regeneration and of long-term storage capacity, before its large-scale routine use. OBJECTIVE To test the survival and recovery of 29 clones of oil palm somatic embryos cryostored for 20 years. MATERIALS AND METHODS Clumps of SEs were pregrown for 7 days on medium containing 0.75 M sucrose, dehydrated in air-tight containers containing silica gel to moisture contents between 19-35% fresh weight, and then immersed directly in liquid nitrogen and stored in cryotanks for 20 years. RESULTS Survival of SEs cryopreserved and rewarmed immediately displayed an average value of 19.1% for the 29 clones tested while survival of SEs rewarmed after 20 years of cryostorage was significantly higher, with an average of 33.2% for the 28 surviving clones. Out of these 28 surviving clones, three were lost due to contamination or regrowth decline...
African Journal of Biotechnology, 2009
Some genetic studies using molecular methods such as diversity assessment or marker-assisted sele... more Some genetic studies using molecular methods such as diversity assessment or marker-assisted selection require collection of a large number of samples from fields located in the vicinity or in remote areas, followed by isolation of good quality DNA in a short time span. In the present study, different tissue preservation methods were compared for subsequent DNA extraction using a modified CTAB method in two 96-well plates, following grinding of leaf tissues with a GenoGrinder 2000. We found that preservation of leaf tissues in NaCl-CTAB-azide buffer (as described in Rogstad, 1992) at 4°C is a better storage procedure than preservation at -20°C to obtain good quality DNA. Comparison of DNA extraction with or without use of phenol revealed that the quality of DNA was not drastically affected when non-phenol extraction protocol was used and did not affect PCR amplification. Thus, the recommended DNA extraction procedure allowed us to process 192 samples per day at a cost of $0.80 per s...
AlterNative: An International Journal of Indigenous Peoples, 2014
People's views of landscape can have signifi cant impact on their land use choices. This in turn ... more People's views of landscape can have signifi cant impact on their land use choices. This in turn can have climate implications. In the literature, there is signifi cant attention paid to the effect of climate on landscape, but as well, there are more examples than one might expect of the effects of landscape change on climate. I present evidence of this from Western Australia and Africa, and some conjectured negative and positive effects in two locations in South Australia. I argue that the land use change affecting the landscape and thus affecting the climate emanates from one's view of landscape. There are also some personal refl ections of perceptions of landscape from someone who started life in a climate and landscape far removed from the South Australian environment within which he has chosen to live.
Cryo letters
DSC analysis was performed at three points in the cryopreservation process on encapsulated-dehydr... more DSC analysis was performed at three points in the cryopreservation process on encapsulated-dehydrated meristems of Ribes ciliatum. Meristems were excised from shoots pre-treated with either sucrose or glucose, encapsulated in alginate beads, dehydrated in sucrose solutions, air dried, and plunged in liquid nitrogen. Thermal analysis revealed glass transitions during cooling of air-desiccated meristems, however, on rewarming a small endothermic event was detected suggesting glass destabilization can occur. Interestingly, this did not occur in alginate beads or meristems when these components were cooled and rewarmed separately. The possibility exists that thermal and moisture gradients may arise within the alginate bead/tissue complex and we propose that the heterogeneous composition of the meristems and the surrounding alginate may promote ice nucleation on rewarming. The significance of this regarding the stabilization of glasses formed in alginate beads and their encapsulated meri...
Encyclopedia of Cell Technology, 2003
In this concept article, we outline a variety of new approaches that have been conceived to addre... more In this concept article, we outline a variety of new approaches that have been conceived to address some of the remaining challenges for developing improved methods of biopreservation. This recognizes a true renaissance and variety of complimentary, high-potential approaches leveraging inspiration by nature, nanotechnology, the thermodynamics of pressure, and several other key fields. Development of an organ and tissue supply chain that can meet the healthcare demands of the 21st century means overcoming twin challenges of (1) having enough of these lifesaving resources and (2) having the means to store and transport them for a variety of applications. Each has distinct but overlapping logistical limitations affecting transplantation, regenerative medicine, and drug discovery, with challenges shared among major areas of biomedicine including tissue engineering, trauma care, transfusion medicine, and biomedical research. There are several approaches to biopreservation, the optimum choice of which is dictated by the nature and complexity of the tissue and the required length of storage. Short-term hypothermic storage at temperatures a few degrees above the freezing point has provided the basis for nearly all methods of preserving tissues and solid organs that, to date, have proved refractory to cryopreservation techniques successfully developed for single-cell systems. In
Wild Crop Relatives: Genomic and Breeding Resources, 2011
ABSTRACT Dioscorea spp., belonging to Dioscoraceae family, are important staple food crop for ove... more ABSTRACT Dioscorea spp., belonging to Dioscoraceae family, are important staple food crop for over 300 million people in the tropics and subtropics. They are mostly grown for their starchy tubers (both cultivated and wild) and for medicinal properties. Cultivated yams are vegetatively propagated while wild yams are sexually propagated and comprise both diploid and polyploid species. Although yam is an economically and socially important crop, limited research has been conducted to understand the complexity of the domestication process traditionally followed mainly in West Africa to develop new cultivars. The genetics and genomics of this crop is least understood due to several biological constraints and lack of research efforts. Some progress, however, has been made recently to understand the phylogeny and phylogenetic relationships within the genus, Dioscorea, and cytogenetics of the wild and cultivated species. Genetic linkage maps have been constructed for one wild species, D. tokoro and two cultivated species, Dioscorea alata and D. rotundata, and QTLs for yam mosaic virus were identified in D. rotundata and anthracnose disease in D. alata. Advances were also made in genetic transformation, including in vitro plant regeneration, gene delivery, and recovery of transgenic plants but this method still needs improvements to generate genetically modified plants. This chapter discusses the available information on Dioscorea, irrespective of wild or cultivated status, as information available on wild species is very limited and is not separable from that of cultivated ones.
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Papers by Dominique Dumet