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See detailLes distorsions de ségrégation chez les plantes et leurs conséquences sur l'amélioration génétique
Diouf, F.B.H.; Mergeai, Guy ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 499-508

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See detailStudy of agronomic constraints to the dissemination of the cultivation of Jatropha curcas L. in Senegal
Terren, Marieke ULg; Saverys, S.; Jacquet de Haveskercke et al

Poster (2012)

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See detaileffets de la substitution totale du tourteau d’arachide par la fève de coton glandless sur les performances zootechniques de poulets de chair au sénégal
Diaw, Mamadou; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Revue d'Elévage et de Médecine Vétérinaire des Pays Tropicaux (2012), 65(1-2), 17-23

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a ... [more ▼]

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a commercial diet (Tém_C), and a very simple diet containing only corn, FCG and a mineral and vitamin concentrate. From the start, the Tém_C and FCG animals showed the highest growths. After 43 days of breeding, there were major differences in body weights between the groups, essentially caused by differences in feed intake, so that the best growth rates were not necessarily linked to better feed conversion ratios. Low body weights, low intakes and high mortality levels were observed with the simple diet. [less ▲]

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See detailAlien chromosome transmission and somatic elimination in monosomic addition lines of Gossypium australe F. Muell in G. hirsutum L
Sarr, Djibril; Lacape, Jean-Marc; Jacquemin, Jean-Marie et al

in Euphytica : International Journal of Plant Breeding (2012), 183

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See detailCulture in vitro de Jatropha curcas L.
Medza Mve, Samson Daudet ULg; Mergeai, Guy ULg; Baudoin, Jean-Pierre ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(4), 567-574

The extension of Jatropha curcas L. cultivation as a biofuel feedstock species requires the distribution of a very large number of plants to the producers in a very short period of time. These plants have ... [more ▼]

The extension of Jatropha curcas L. cultivation as a biofuel feedstock species requires the distribution of a very large number of plants to the producers in a very short period of time. These plants have to be able to give a high oil yield and be morphologically and phenotypically homogeneous to facilitate cultural operations. If high oil content can be obtained by varietal selection, the achievement of homogeneous material passes by the in vitro propagation. Various methods of mass production of plant material by axenic culture have been published. This study reviews the protocols published for in vitro propagation of J. curcas and discusses their applicability to an industrial scale. [less ▲]

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See detailThe SRI celebrates its 30th anniversary
Mergeai, Guy ULg

in Tropicultura (2011), 29(3), 129-130

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See detailJatropha curcas: Miraculous Plant or Tree of the Devil ?
Mergeai, Guy ULg

in Tropicultura (2011), 29(1),

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See detailIsolation of five new monosomic alien addition lines of Gossypium australe F. Muell in G. hirsutum L. by SSR and GISH analyses
Sarr, D.; Lacape, J.-M.; Rodier-Goud, M. et al

in Plant Breeding (2011), 130

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated ... [more ▼]

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated cotton species. To isolate monosomic alien addition lines (MAALs) of G. australe in G. hirsutum, the [2(G. hirsutum X G. australe) X G. hirsutum] pentaploid (2n = 5x = 65) was backcrossed as male parent to G. hirsutum. Analysis of 42 BC1 plants and seven alien addition lines, already available, with 150 SSR markers developed from G. hirsutum revealed a cross-species amplification rate of 100% and a polymorphism rate of 56%. Eighty polymorphic SSR markers generated 87 G. australe-specific loci that have been assigned by a hierarchical cluster analysis to 13 linkage groups corresponding to the 13 chromosomes of G. australe. Analysis by SSR markers and genomic in situ hybridization of the self-progeny of disomic alien addition lines, backcross progeny of the pentaploid, allowed the isolation of five new MAALs. [less ▲]

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See detailLes co-produits de la graine de coton en alimentation du poulet de chair
Diaw, Mahamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Annales de Médecine Vétérinaire (2011), 155

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal ... [more ▼]

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal nutrition, andparticularly in broilers, is especiallylimited by the free gossypolwhich can damage varioustissues and also decreases theperformances of growth and dietefficiency. The incorporation ofcottonseed meal in broilers dietmay be increased following chemicalbinding of free gossypol,but these methods have drawbacks.Ferrous sulfate denaturesfeed and the use of lysine to bindgossypol is limited by the expensivenessof this product while thebiological fermentation is verycomplex and inapplicable, as tonow, on a large way. Glandlessvarieties could be incorporatedat a very high level in diets andtherefore could contribute todecrease the protein feed requirements.Unfortunately, agronomicconstraints associated to thesecrops have limited the research inthis way. The production of varietiesin which gossypol secretionwould be inhibited before theseed germination should alleviatethe limitations associated to cottonby-products. [less ▲]

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See detailJatropha curcas in sub-saharian Africa: The big illusion ?
Mergeai, Guy ULg; Terren, Marieke ULg; Jacquet de Haveskercke, P. et al

Conference (2011)

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See detailEvaluation agromorphologique et sélection des meilleures accessions de Pourghère (Jatropha curcas L.) introduites au Bénin
Ahoton, L. E.; Quenum, F.; Mergeai, Guy ULg

in International Journal of Biological and Chemical Sciences (2011), 5(4), 1619-1627

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See detailInsecticidal effect of Jatropha curcas oil on the aphid Aphis fabae (Hemiptera: Aphididae) and on the main insect pests associated with cowpeas (Vigna unguiculata) in Niger
Abdoul Habou, Zakari; Haougui, A.; Mergeai, Guy ULg et al

in Tropicultura (2011), 29(4), 225-229

The insecticidal activity of Jatropha curcas has been evaluated on various crop pests. Oil concentrations of 0.5, 1, 2.5, 5, 10 and 15% were first tested on the black bean aphid (Aphis fabae Scop.) as ... [more ▼]

The insecticidal activity of Jatropha curcas has been evaluated on various crop pests. Oil concentrations of 0.5, 1, 2.5, 5, 10 and 15% were first tested on the black bean aphid (Aphis fabae Scop.) as part of an efficacy test conducted in the laboratory. During a second stage, the insecticidal efficacy of 5 and 7.5% oil concentrations was evaluated on the main pests infesting cowpea crops (Vigna unguiculata L.) as part of a field test conducted at the University of Niamey (Niger). The results obtained in the two tests demonstrate the biocidal effect of the treatments applied, which increases with the concentration. On the black bean aphid, the biocidal effect increases during the hours following the application of oil before reaching a peak after 4 days. On cowpeas, J. curcas oil concentrations of 5% and 7.5% make it possible to reduce the level of attack by aphids (Aphis craccivora) by 10 and 50% respectively compared to the control. A 50% and 75% fall in the number of thrips (Megalurothrips sjöstedti) and bugs (Anoplocnemis curvipes), respectively, can be observed under the same conditions. This treatment made it possible to greatly increase yields compared to the untreated control. [less ▲]

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See detailAmélioration du taux de multiplication in vitro de Jatropha curcas L.
Medza Mve, Samson Daudet ULg; Mergeai, Guy ULg; Baudoin, Jean-Pierre ULg et al

in Tropicultura (2010), 28(4), 200-204

In order to improve the in vitro multiplication rate (number of shoots/explant/subculture) of Jatropha curcas L. axillary nodes taken from young plants of two accessions of this species (originating from ... [more ▼]

In order to improve the in vitro multiplication rate (number of shoots/explant/subculture) of Jatropha curcas L. axillary nodes taken from young plants of two accessions of this species (originating from Cameroon and Senegal) have been cultivated for three weeks on a MS medium supplemented with 8,87 µM BAP, 4.92 µM IBA, and 30 g.l-1 sucrose at pH 5.7±0.1, and solidified with 0.7% agar. The shoots obtained from each original explant were then transferred to proliferation media (PM) consisting of MS medium supplemented with 2.21 to 8.9 µM BA or 2.21 to 8.9 µM kinetin in combination with 2.46 µM IBA. Each combination was completed with 33.12 µM adenine sulfate, 82.92 µM of glutamine and 30 g.l-1 sucrose. The best multiplication rate was obtained for the PM medium containing 6.65 µM BA and 2.46 µM AIB. On this medium 42.72±3.22 and 38.15±4.7 shoots/explant were obtained respectively for the accessions from Cameroon and Senegal after 6 weeks of culture, and the mean multiplication rates were 8.27±1.27 (accession from Cameroon) and 7.89±1.13 (accession from Senegal) shoots per explant during the 7 following subcultures (3 weeks/subculture). This medium was also the one that allowed the best overall growth in shoot height. Leafy shoots obtained have been rooted in a medium containing half of the major mineral components of MS supplemented with 5.7 µM IBA, 1.5% sucrose and solidified with 0.7% agar, then acclimated with a survival rate of 97%. These results allow considering the establishment of industrial units of plantlet multiplication from elite clones of J. curcas. [less ▲]

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See detailIdentification of chromosomal regions associated with segregation distortion of SSR markers and the genes controlling the low-gossypol seed & high-gossypol plant trait of Gossypium sturtianum
Benbouza, H.; Diouf, F.B.; Schefflers, J. et al

Conference (2010)

Distorted segregation of DNA markers is commonly encountered, especially in inter-specific crosses. Our main objective in this study was to identify chromosomal regions consistently associated with ... [more ▼]

Distorted segregation of DNA markers is commonly encountered, especially in inter-specific crosses. Our main objective in this study was to identify chromosomal regions consistently associated with segregation distortion in [(G. hirsutum x G. raimondii) x G. sturtianum] (HRS) hybrid. Segregation distortion skews the genotypic frequencies from their Mendelian expectations. In HRS progeny, chi square analysis (P < 0.01) showed significant skewed in all targeted linkage groups c2-c14, c3-c17, and c6-c25. Chromosomal region was regarded as being associated with skewed segregation, if three or more closely linked markers exhibited significant segregation distortion in one or more population(s). The targeted introgression regions in the tested population seem to be favourable for segregation distortion. Segregation distortion in HRS hybrid progenies differed in male and female gametes. Furthermore, the data indicated that the environment has strongly influenced the transfer of SSR markers through microspores. The consistent location of these chromosomal regions in selfed and backcross of HRS derivatives indicate probably the identification of segregation distortion regions (SDRs) in HRS hybrid. Comparison with results regarding the segregation distortion regions obtained in previous research by other authors and results we obtained regarding the absence of recombinations between BNL3436 and BNL1153 markers mapped on c6-c25 chromosome and spanned by 64 cM on the G. hirsutum map, after several generations of selfing, arise the question of the conservation of the gene order and spacing in G. sturtianum. Results showed that three SSR markers mapped on c6-c25 linkages groups were systematically transmitted in all selected progenies of the HRS tri-specific hybrid. Furthermore, the high percentages of loci with significant segregation distortion observed in this study suppose that a genetic mechanism may exist for preferential transmission of alien chromosomes segments. High heterozygosity frequencies (+/- 80%) were observed for all conserved G. sturtianum SSR markers, after several generations of backcrossing and selfing, which indicate that the cytogenetic and genetic conditions for obtaining homozygotes at high frequency are not met. [less ▲]

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See detailFertilité des sols, agriculture durable de conservation pour préserver la planète
Mergeai, Guy ULg; Aloni Komanda, Jules

in La voix du Congo profond, le magazine d'un congo rural en marche (2010)

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See detailEffect of groundnut cake substitution by glandless cottonseed kernels on broilers production: animal performance, nutrient digestibility, carcass characteristics and fatty acid composition of muscle and fat
Diaw, Mamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in International Journal of Poultry Sciences (2010), 9(5), 473-481

A study has been conducted with broilers to assess, during the rainy season, the effects of groundnut cake substitution by glandless Cottonseed Kernel (CSK), at levels of 0, 25, 50 and 75%. The ... [more ▼]

A study has been conducted with broilers to assess, during the rainy season, the effects of groundnut cake substitution by glandless Cottonseed Kernel (CSK), at levels of 0, 25, 50 and 75%. The substitution improved linearly feed intake and animal growth, as well as carcass component weights and allometric parameters. The CSK increased the C18:2 n-6 to C18:1 n-9 ratio, as well in diet as in meat and subcutaneous fat. In order to explain the observed performances, the possibility is considered that broilers used preferentially C18:2 n-6 fatty acids for their metabolism. Complete glandless cottonseed kernels are probably highly valuable for broilers production in warm and wet conditions. [less ▲]

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See detailDevelopment of upland cotton plants highly resistant to the reniform nematode from the G. Hirsutum x G. Thurberi x G. Longicalyx hybrid
Mergeai, Guy ULg; Konan, N.O; Baudoin, Jean-Pierre ULg

in Proceedings of the beltwide cotton improvement conference (2010)

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See detailEffect of GammaRay in the Progeny of Trispecific Hybrid [(Gossypium hirsutum x G. raimondii)² x G. sturtianum]
Diouf, Fatimata Bintou Hassédine ULg; Benbouza, H; Konan, O et al

in Notulae Botanicae Horti Agrobotanici Cluj-Napoca (2010), 38

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