J. A. Atkinson, L. U. Wingen, M. Griffiths, M. P. Pound, O. Gaju et al., Phenotyping pipeline reveals major seedling root growth QTL in hexaploid wheat, Journal of Experimental Botany, vol.66, issue.8, pp.2283-2292, 2015.
DOI : 10.1093/jxb/erv006
URL : https://hal.archives-ouvertes.fr/hal-01245197

A. Bationo, J. Kihara, B. Vanlauwe, B. Waswa, and J. Kimetu, Soil organic carbon dynamics, functions and management in West African agro-ecosystems, Agricultural Systems, vol.94, issue.1, 2007.
DOI : 10.1016/j.agsy.2005.08.011

A. Berg, D. Noblet-ducoudré, N. Sultan, B. Lengaigne, M. Guimberteau et al., Projections of climate change impacts on potential C4 crop productivity over tropical regions, Agricultural and Forest Meteorology, vol.170, pp.89-102, 2013.
DOI : 10.1016/j.agrformet.2011.12.003
URL : https://hal.archives-ouvertes.fr/hal-01496000

H. Brück, B. Sattelmacher, and W. A. Payne, Varietal differences in shoot and rooting parameters of pearl millet on sandy soils in Niger, Plant and Soil, vol.251, issue.1, pp.175-185, 2003.
DOI : 10.1023/A:1022932815486

M. Guigaz, FAOSTAT Database Available at: http://faostat3.fao.org/browse, Memento de l'Agronome. Montpellier: CIRAD-GRET and Ministère des Affaires Étrangères, 2002.

S. Henry, F. Divol, M. Bettembourg, C. Bureau, E. Guiderdoni et al., Immunoprofiling of Rice Root Cortex Reveals Two Cortical Subdomains, Frontiers in Plant Science, vol.2014, issue.790, 2016.
DOI : 10.1155/2014/181727

W. Hetz, F. Hochholdinger, M. Schwall, and G. Feix, Isolation and characterization of rtcs, a maize mutant deficient in the formation of nodal roots, The Plant Journal, vol.10, issue.5, pp.845-857, 1950.
DOI : 10.1046/j.1365-313X.1996.10050845.x

F. Hochholdinger, W. J. Park, M. Sauer, and K. Woll, From weeds to crops: genetic analysis of root development in cereals, Trends in Plant Science, vol.9, issue.1, pp.42-48, 2004.
DOI : 10.1016/j.tplants.2003.11.003

F. Hochholdinger and R. Tuberosa, Genetic and genomic dissection of maize root development and architecture, Current Opinion in Plant Biology, vol.12, issue.2, 2009.
DOI : 10.1016/j.pbi.2008.12.002

M. Lartaud, C. Perin, B. Courtois, E. Thomas, S. Henry et al., PHIV-RootCell: a supervised image analysis tool for rice root anatomical parameter quantification, Frontiers in Plant Science, vol.9, issue.105, 2014.
DOI : 10.1038/nmeth.2089

G. Lobet, L. Pagès, and X. Draye, A Novel Image-Analysis Toolbox Enabling Quantitative Analysis of Root System Architecture, Plant Physiology, vol.157, issue.1, pp.29-39, 2011.
DOI : 10.1104/pp.111.179895

J. P. Lynch, Root Phenes for Enhanced Soil Exploration and Phosphorus Acquisition: Tools for Future Crops, PLANT PHYSIOLOGY, vol.156, issue.3, pp.1041-1049, 2011.
DOI : 10.1104/pp.111.175414

M. Meijón, S. B. Satbhai, T. Tsuchimatsu, and W. Busch, Genome-wide association study using cellular traits identifies a new regulator of root development in Arabidopsis, Nature Genetics, vol.57, issue.1, pp.77-81, 2014.
DOI : 10.1093/beheco/ark016

B. Muller, M. Stosser, and F. Tardieu, Spatial distributions of tissue expansion and cell division rates are related to irradiance and to sugar content in the growing zone of maize roots, Plant, Cell and Environment, vol.20, issue.2, pp.149-158, 1998.
DOI : 10.1086/336860

H. S. Neufeld, D. M. Durall, P. M. Rich, and D. T. Tingey, A rootbox for quantitative observations on intact entire root systems, Plant and Soil, vol.72, issue.2, pp.295-298, 1989.
DOI : 10.1007/BF02220725

I. Oumar, C. Mariac, J. Pham, and Y. Vigouroux, Phylogeny and origin of pearl millet (Pennisetum glaucum [L.] R. Br) as revealed by microsatellite loci, Theoretical and Applied Genetics, vol.291, issue.12, pp.489-497, 2008.
DOI : 10.1007/s00122-008-0793-4

A. M. Pahlavanian and W. K. Silk, Effect of Temperature on Spatial and Temporal Aspects of Growth in the Primary Maize Root, PLANT PHYSIOLOGY, vol.87, issue.2, pp.529-532, 1988.
DOI : 10.1104/pp.87.2.529

M. P. Pound, A. P. French, J. A. Atkinson, D. M. Wells, M. J. Bennett et al., RootNav: Navigating Images of Complex Root Architectures, PLANT PHYSIOLOGY, vol.162, issue.4, pp.1802-1814, 2013.
DOI : 10.1104/pp.113.221531

J. Pritchard, A. D. Tomos, W. Jones, and R. G. , Control of Wheat Root Elongation Growth, Journal of Experimental Botany, vol.38, issue.6, pp.948-959, 1987.
DOI : 10.1093/jxb/38.6.948

R. Development and C. Team, R: A Language and Environment for Statistical Computing Vienna: R Foundation for Statistical Computing Available at, 2008.

J. Rebouillat, A. Dievart, J. L. Verdeil, J. Escoute, G. Giese et al., Molecular Genetics of Rice Root Development, Rice, vol.33, issue.Spec No, pp.15-34, 2009.
DOI : 10.1007/s12284-008-9016-5

A. A. Saïdou, C. Mariac, V. Luong, J. L. Pham, G. Bezançon et al., Association Studies Identify Natural Variation at PHYC Linked to Flowering Time and Morphological Variation in Pearl Millet, Genetics, vol.182, issue.3, pp.899-910, 2009.
DOI : 10.1534/genetics.109.102756

B. Scheres, H. Wolkenfelt, V. Willemsen, M. Terlouw, E. Lawson et al., Embryonic origin of the Arabidopsis primary root and root meristem initials, Development, vol.2487, pp.2475-2487, 1038.

S. W. Souci, W. Fachmann, and H. Kraut, Food Composition and Nutrition Tables, 2000.

D. Tolivia and J. Tolivia, Fasga: A new polychromatic method for simultaneous and differential staining of plant tissues, Journal of Microscopy, vol.91, issue.1, pp.113-117, 1987.
DOI : 10.1111/j.1365-2818.1987.tb02859.x

M. Watt, L. J. Magee, and M. E. Mccully, Types, structure and potential for axial water flow in the deepest roots of field-grown cereals, New Phytologist, vol.89, issue.1, pp.135-146, 2008.
DOI : 10.1046/j.1469-8137.2003.00893.x

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