Mycorrhizas and biomass crops: opportunities for future sustainable development

Central to soil health and plant productivity in natural ecosystems are in situ soil microbial communities, of which mycorrhizal fungi are an integral component, regulating nutrient transfer between plants and the surrounding soil via extensive mycelial networks. Such networks are supported by plant-derived carbon and are likely to be enhanced under coppiced biomass plantations, a forestry practice that has been highlighted recently as a viable means of providing an alternative source of energy to fossil fuels, with potentially favourable consequences for carbon mitigation. Here, we explore ways in which biomass forestry, in conjunction with mycorrhizal fungi, can offer a more holistic approach to addressing several topical environmental issues, including ‘carbon-neutral’ energy, ecologically sustainable land management and CO2 sequestration

Opportunités et contraintes agroforestières de Ricinodendron heudelotii au Cameroun

Ricinodendron heudelotii est une essence endémique des forêts tropicales humides d’Afrique, très prisée pour ses graines comestibles. Sa régénération naturelle reste difficile à cause principalement de la dormance tégumentaire de ses graines. Elle possède de nombreuses vertus ethnobotaniques et d’opportunités agroforestières pour les peuples des forêts du bassin du Congo. Au nombre de ces vertus, on cite des propriétés médicinales, agroalimentaires, agronomiques, écologiques et industrielles. Des programmes de domestication de R. heudelotii sont en cours dans les stations du Centre Mondial de l’Agroforesterie (CMAF) au Cameroun. L’essentiel des travaux déjà réalisés sur cette essence a porté sur ses propriétés ethnobotaniques, l’analyse de la composition chimique de l’huile des graines et sa domestication. Les tentatives de domestication de R. heudelotii se heurtent par ailleurs à diverses contraintes phytosanitaires encore à identifier. Sur la base des observations réalisées en forêts, dans les pépinières et au laboratoire, les dégâts observés seraient d’origine fongique et entomologique. À ce jour, aucun programme de lutte ou d’amélioration génétique n’est envisagé. Pourtant, l’existence de deux sous-espèces (heudelotii et africanum) chez R. heudelotii et d’une espèce apparentée (R. rautanenii) constitue un atout exploitable pour d’éventuels travaux d’amélioration génétique. Cette étude suggère que R. heudelotii pourrait être considérée comme une essence modèle d’avenir pour l’agroforesterie au Cameroun, avec au premier plan un moyen de lutte prometteur contre la pauvreté, et propose quelques pistes de recherche en vue de contribuer au succès des programmes de  domestication de l’espèce. © 2013 International Formulae Group. All rights reserved.Mots clés : Ricinodendron heudelotii, intérêt agroécologique, contraintes agroforestières, amélioration génétique

Variation phénotypique des traits quantitatifs de Cavia porcellus : une première étape vers l’amélioration de l’espèce en RD Congo

Objectif : Dans l’optique de la promotion de l’élevage du cobaye, Cavia porcellus, nous avons mené une étude d’analyse des paramètres de sa productivité (croissance et taille de nichée).Méthodologie et résultats : Le poids vif moyen à la naissance est de 70,4 ± 20,5g pour les deux sexes. A 4 semaines ce poids a été multiplié par 2,6 ; il a continué à augmenter jusqu’à 20 semaines, âge de maturité sexuelle des cobayes ; le poids vif moyen des adultes est de 375 ± 78,2g pour les femelles et de 512 ± 115g pour les mâles. La longueur du corps de l’animal présente une allure ascendante continue ; elle est de 9,49 ± 2,71 cm ; 12,0 ± 1,39 cm et 22,8 ± 1,25cm respectivement à la naissance, au sevrage (à 3 semaines) et à 20 semaines (âge de maturité sexuelle) ; la longueur moyenne d’adulte est respectivement de 23,5 ± 1,77 cm pour les femelles et 24,1 ± 0,98 cm pour les mâles. La taille moyenne de la nichée pour les femelles de Kisantu, Belgique, Bukavu et Kinshasa est respectivement de 1,73 ± 0,45 ; 3,14 ± 0,77 ; 2,90 ± 0,67 et 2,48 ± 1,27 petits ; très avantageuse pour les femelles originaires de Belgique. L’héritabilité enregistrée chez les hybrides est modérée, variant entre 0,43 et 0,64 ; l’hétérosis est importante à la première génération et ensuite elle diminue d’environ 25% au fur et à mesure que les générations se succèdent. Les valeurs de coefficient de répétabilité observées pour le poids vif à la naissance, au sevrage et à 20 semaines ont montré une forte répétabilité de caractères de croissance (R=0,94 ; R=0,86 et R=0,98).Conclusion et application des résultats : L’amélioration des paramètres de productivité (croissance et taille de nichée) est possible chez les cobayes locaux, mais elle exige l’apport des géniteurs performants venant soit d’autres régions du pays, soit d’ailleurs (Belgique). Ainsi, nous pouvons promouvoir et améliorer l’élevage du cobaye en procédant au croisement entre géniteurs locaux, mais aussi avec des géniteurs exotiques.Mots clés : variation phénotypique, poids vif, longueur du corps, taille de la nichée, Cavia porcellus, R D Cong

Characterization of six microsatellite loci in Myrica faya (Myricaceae) and cross amplification in the endangered endemic M. rivas-martinezii in Canary Islands, Spain

Six novel polymorphic microsatellite markers were isolated from enriched libraries in Myrica faya Ait., recently renamed Morella faya, (fayatree, firetree, or firebush) in order to examine the genetic diversity in natural populations. Also, test cross-specific amplification and genetic diversity in Myrica rivas-martinezii, which is endemic on the Canary islands. Microsatellite loci were screened in 225 individuals of both species from different islands of the Canarian archipelago. All markers were successfully amplified from both Myrica species, with an average number of 6.5 and 9.3 alleles per locus in M. rivas-martinezii and M. faya, respectively. There was no evidence for linkage disequilibrium between loci, and the probability of null alleles ranged from 0.01 to 0.17

Breeding without Breeding: Is a Complete Pedigree Necessary for Efficient Breeding?

Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called “Breeding without Breeding” (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB

An interlaboratory comparison on the characterization of a sub-micrometer polydisperse particle dispersion

The measurement of polydisperse protein aggregates and particles in biotherapeutics remains a challenge, especially for particles with diameters of ≈ 1 µm and below (sub-micrometer). This paper describes an interlaboratory comparison with the goal of assessing the measurement variability for the characterization of a sub-micrometer polydisperse particle dispersion composed of five sub-populations of poly(methyl methacrylate) (PMMA) and silica beads. The study included 20 participating laboratories from industry, academia, and government, and a variety of state-of-the-art particle-counting instruments. The received datasets were organized by instrument class to enable comparison of intralaboratory and interlaboratory performance. The main findings included high variability between datasets from different laboratories, with coefficients of variation from 13 % to 189 %. Intralaboratory variability was, on average, 37 % of the interlaboratory variability for an instrument class and particle sub-population. Drop-offs at either end of the size range and poor agreement on maximum counts of particle sub-populations were noted. The mean distributions from an instrument class, however, showed the size-coverage range for that class. The study shows that a poly-disperse sample can be used to assess performance capabilities of an instrument set-up (including hardware, software, and user settings) and provides guidance for the development of polydisperse reference materials.Drug Delivery Technolog

Perspectives on the use of transcriptomics to advance biofuels

As a field within the energy research sector, bioenergy is continuously expanding. Although much has been achieved and the yields of both ethanol and butanol have been improved, many avenues of research to further increase these yields still remain. This review covers current research related with transcriptomics and the application of this high-throughput analytical tool to engineer both microbes and plants with the penultimate goal being better biofuel production and yields. The initial focus is given to the responses of fermentative microbes during the fermentative production of acids, such as butyric acid, and solvents, including ethanol and butanol. As plants offer the greatest natural renewable source of fermentable sugars within the form of lignocellulose, the second focus area is the transcriptional responses of microbes when exposed to plant hydrolysates and lignin-related compounds. This is of particular importance as the acid/base hydrolysis methods commonly employed to make the plant-based cellulose available for enzymatic hydrolysis to sugars also generates significant amounts of lignin-derivatives that are inhibitory to fermentative bacteria and microbes. The article then transitions to transcriptional analyses of lignin-degrading organisms, such as Phanerochaete chrysosporium, as an alternative to acid/base hydrolysis. The final portion of this article will discuss recent transcriptome analyses of plants and, in particular, the genes involved in lignin production. The rationale behind these studies is to eventually reduce the lignin content present within these plants and, consequently, the amount of inhibitors generated during the acid/base hydrolysis of the lignocelluloses. All four of these topics represent key areas where transcriptomic research is currently being conducted to identify microbial genes and their responses to products and inhibitors as well as those related with lignin degradation/formation.clos