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Billot C.,CIRAD - Agricultural Research for Development | Rivallan R.,CIRAD - Agricultural Research for Development | Sall M.N.,CERAAS | Fonceka D.,CIRAD - Agricultural Research for Development | And 8 more authors.
American Journal of Botany | Year: 2012

Premise of the study: Discrepancies in terms of genotyping data are frequently observed when comparing simple sequence repeat (SSR) data sets across genotyping technologies and laboratories. This technical concern introduces biases that hamper any synthetic studies or comparison of genetic diversity between collections. To prevent this for Sorghum bicolor, we developed a control kit of 48 SSR markers. • Methods and Results: One hundred seventeen markers were selected along the genome to provide coverage across the length of all 10 sorghum linkage groups. They were tested for polymorphism and reproducibility across two laboratories (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement [CIRAD], France, and International Crops Research Institute for the Semi-Arid Tropics [ICRISAT], India) using two commonly used genotyping technologies (polyacrylamide gel-based technology with LI-COR sequencing machines and capillary systems with ABI sequencing apparatus) with DNA samples from a diverse set of 48 S. bicolor accessions. • Conclusions: A kit for diversity analysis was developed. It contains information on 48 technically robust sorghum microsatellite markers and 10 DNA controls. It can further be used to calibrate sorghum SSR genotyping data acquired with different technologies and compare those to genetic diversity references. © 2012 Botanical Society of America. Source


Norliette Z.S.H.,University Abomey Calavi | Emile A.C.,Cheikh Anta Diop University | Bassiaka O.,CERAAS | Achille A.,University Abomey Calavi | And 2 more authors.
Advances in Environmental Biology | Year: 2013

Rain fed agriculture is a common practice in most tropical regions. With a huge potential which unfortunately remains underexploited, Africa is constantly faced with the problems of self-sufficiency. Rice became especially since 1990 one of the most important food crops in Africa. Since colonial times, many governments of least developed countries have adopted policies to promote the introduction of rice as a staple food for urban populations growing. Considering harvested area, rice is the fifth most important cereal in Africa and the fourth in terms of production. In Africa, rice production is increasing at the highest rate of any cereal. The inherent problems in upland rice production are mostly due to climatic change conditions prevailing in ecological production areas, declining soil fertility, low availability of land and many other factors. In this context, lowland agriculture production is the best and offer potential in rain fed agriculture which can be practice with less difficulty and risk, because water is more available. However, farmers are facing to important phytosanitary problems and one of the most important is the angiosperm parasite rice: Rhamphicarpafistulosa (Hochst.) Benth.Rhamphicarpa fistulosa is a parasitic weed of Orobanchiacea family. Six species of Rhamphicarpa genuswere mainly native to Africa, India and Australia. Two species are native to southern Africa. On those two species, we have Rhamphicarpa fistulosa and Rhamphicarpabredivepedicillata. Rhamphicarpa fistulosa,a facultative parasite, can cause yield losses ranging from 40% to 100%. Little information is available on the parasite and its host interaction. Rhamphicarpa fistulosa connect its xylem system to the host plant through haustorium. Parenchyma cells building were towards differentiated with cells provided by the periphery of the haustorium. According to certain scientist, a non polysaccharidic material staining dark red with saframin has been founded for different scrophulariacea. The interface between Rhamphicarpa fistulosa and the roots of its hosts never showed a secretion even if on semithin sections, a darkly staining could be observed.Little control option is also available in the management of this pest. © 2013 AENSI Publisher All rights reserved. Source


de Alencar Figueiredo L.F.,CIRAD - Agricultural Research for Development | de Alencar Figueiredo L.F.,University of Brasilia | Sine B.,CERAAS | Chantereau J.,CIRAD - Agricultural Research for Development | And 6 more authors.
Theoretical and Applied Genetics | Year: 2010

To ensure food security in Africa and Asia, developing sorghum varieties with grain quality that matches consumer demand is a major breeding objective that requires a better understanding of the genetic control of grain quality traits. The objective of this targeted association study was to assess whether the polymorphism detected in six genes involved in synthesis pathways of starch (Sh2, Bt2, SssI, Ae1, and Wx) or grain storage proteins (O2) could explain the phenotypic variability of six grain quality traits [amylose content (AM), protein content (PR), lipid content (LI), hardness (HD), endosperm texture (ET), peak gelatinization temperature (PGT)], two yield component traits [thousand grain weight (TGW) and number of grains per panicle (NBG)], and yield itself (YLD). We used a core collection of 195 accessions which had been previously phenotyped and for which polymorphic sites had been identified in sequenced segments of the six genes. The associations between gene polymorphism and phenotypic traits were analyzed with Tassel. The percentages of admixture of each accession, estimated using 60 RFLP probes, were used as cofactors in the analyses, decreasing the proportion of false-positive tests (70%) due to population structure. The significant associations observed matched generally well the role of the enzymes encoded by the genes known to determine starch amount or type. Sh2, Bt2, Ae1, and Wx were associated with TGW. SssI and Ae1 were associated with PGT, a trait influenced by amylopectin amount. Sh2 was associated with AM while Wx was not, possibly because of the absence of waxy accessions in our collection. O2 and Wx were associated with HD and ET. No association was found between O2 and PR. These results were consistent with QTL or association data in sorghum and in orthologous zones of maize. This study represents the first targeted association mapping study for grain quality in sorghum and paves the way for marker-aided selection. © 2010 Springer-Verlag. Source


Traore S.B.,Regional Center | Alhassane A.,Regional Center | Muller B.,CERAAS | Muller B.,CIRAD - Agricultural Research for Development | And 11 more authors.
Atmospheric Science Letters | Year: 2011

The Sahel region is known for the high vulnerability of its agriculture to climate variability. Early warning systems that make use of agrometerological forecasts are one of the coping strategies developed by policy makers. However, the predictive quality of the tools and methods used needs improvement. In order to address some of these challenges, we conducted agronomic trials and on-farm surveys to adapt the SARRAH (Système d'Analyse Régionale des Risques Agroclimatiques, version H) crop simulation model, and also evaluated it in farmers' field conditions. The farmers' practices such as sowing dates and densities, fertilizer use and yields potentials of the millet and sorghum crops were characterized under different climatic conditions. Copyright © 2010 Royal Meteorological Society. Source

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