H. R. Lafitte, A. H. Price and B. Courtois, “Yield response to water deficit in an upland rice mapping population: Associations among traits and genetic markers”, Theoretical and Applied Genetics, Vol. 109, 2004, pp. 1237-1246.
 J. C. O’Toole, “Adaptation of rice to drought-prone environments”, In: IRRI (ed) “Drought Resistance in Crops with the Emphasis on Rice”. International Rice Research Institute, Manila, 1982, pp 195-213.
 A. H. Price and A. D. Tomos, “Genetic dissection of root growth in rice (Oryza sativa L.). II: mapping quantitative trait loci using molecular markers”, Theoretical and Applied Genetics, Vol. 95, 1997, pp. 143-152.
 A. H. Price, K. A. Steele, B. J. Moore and R. G. W. Jones, “Upland rice grown in soil-filled chambers and exposed to contrasting water-deficit regimes II Mapping quantitative trait loci for root morphology and distribution”, Field Crops Research, Vol. 76, 2002, pp.25-43.
 M. C. Champoux, G. Wang, S. Sarkarung, D. J. Mackill, J. C. O’Toole, N. Huang and S. R. McCouch, “Locating genes associated with root morphology and drought avoidance in rice via linkage to molecular markers”, Theoretical and Applied Genetics, Vol. 90, 1995, pp. 969-981.
 R. Yadav, B. Courtois, N. Huang, G. McLaren, “Map ping genes controlling root morphology and root distribu tion in a double haploid population of rice”, Theoretical and Applied Genetics, Vol. 94, 1997, pp. 619- 632.
 J. Zhang, H. G. Zheng, A. Alarti, G. Pantuwan, T.T. Nguyen, J. N. Tripathy, A. K. Sarial, S. Robin, R. C. Babu, B. D. Nguyen, S. Sarkarung, A. Blum, H.T. Nguyen, “Locating genomic regions associated with components of drought resistance in rice: comparative mapping within and across species”, Theoretical and Applied Genetics, Vol. 103, 2001a, pp. 19-29.
 A. Kamoshita, L. J. Wade, M. L. Ali, M. S. Pathan, J. Zhang, S. Sakarung and H. T. Nguyen, “Mapping QTLs for root morphology of a rice population adapted to rainfed lowland conditions”, Theoretical and Applied Genetics, Vol. 104, 2002a, pp. 880-893.
 Z. Li, P. Mu, C. Li, H. Zhang, Z. Li, Y. Gao and X, “Wang QTL mapping of root traits in a doubled haploid population from a cross between upland and lowland japonica rice in three environments”, Theoretical and Applied Genetics, Vol. 110, 2005, pp. 1244-252.
 B. S. Zheng, L. Yang, W. P.,Zhang, C. Z. Mao, Y. R. Wu, K. K. Yi, Y. Liu and P. Wu, “Mapping QTLs and candidate genes for rice root traits under different water-supply conditions and comparative analysis across three populations”, Theoretical and Applied Genetics, Vol. 107: 2003, pp. 1505-1515.
 B. Zheng, L. Yang, C. Mao, Y. Huang and P. Wu, “Comparison of QTLs for rice seedling morphology under different water supply conditions”, Journal of Genetics and Genomics, Vol. 35, 2008, pp.473-484.
 K. Cui, J. Huang, Y. Xing, S. Yu, C. Xu and S. Peng, “Mapping QTLs for seedling characteristics under different water supply conditions in rice (Oryza sativa L.)”, Physiologia Plantarum, Vol. 132, 2008, 53-68.
 K. A. Steele, A. H. Price, H. E. Shashidhar, J. R. Witcombe, “Marker-assisted selection to introgress rice QTLs controlling root traits into an Indian upland rice variety” Theoretical and Applied Genetics, Vol. 112, 2006, pp. 208-221.
 L. Liu, P. Mu, X. Li, Y. Qu, Y. Wang and Z. Li, “Localization of QTL for basal root thickness in japonica rice and effect of marker-assisted selection for a major QTL”, Euphytica, Vol. 164, 2008, pp. 729-737.
 S. Basu, A. Roychoudhury, P. P. Saha and D. N. Sengupta “Comparative analysis of some biochemical responses of three indica rice varieties during polyethylene glycol-mediated water stress exhibits distinct varietal difference”, Acta Physiologiae Plantarum, Vol. 32, No. 3, 2010, pp. 551-563.
 S. Yoshida and S. Hasegawa, “The rice root system: its development and function”, In: IRRI (ed) “Drought Resistance in Crops with the Emphasis on Rice”, International Rice Research Institute, Manila, 1982, pp 83-96.
 A. J. ,Ali, J. L. Xu, A. M. Ismail, B. Y. Fu, C. H. M. Vijaykumar, Y. M. Gao, J. Domingo, R. Maghirang, S. B. Yu, G. Gregorio, S. Yanaghihara, M. Cohen, B. Carmen, D. Mackill and Z.K. Li, “Hidden diversity for abiotic and biotic stress tolerances in the primary gene pool of rice revealed by a large backcross breeding program”, Field Crops Research, Vol. 97, 2006, pp.66-76.
 H. R. Lafitte, C. H. M. Vijayakumar, Y. M. Gao, Y. Shi, J. L. Xu, B. Y. Fu, S. B. Yu, A. J. Ali, J. Domingo, R. Maghirang, R. Torres, D. Mackill, Z. K. Li, “Improvement of rice drought tolerance through backcross breeding: Evaluation of donors and selection in drought nurseries” Field Crops Research, Volume 97, No. 1, May 2006, pp. 77-86.
 G. B. Gregorio, D. Sendhira, R. D. Mendoza, N. L. Manigbas, J. P. Roxas and C. Q. Guerta, “Progress in breeding for salinity tolerance and associated abiotic stresses in rice”, Field Crops Research, Vol. 76, 2002, pp. 91-101.
 E. Fernandes, A. Pacheco and C. Penha-gon?alves, “Mapping of quantitative trait loci using the skew-normal distribution”, Journal of Zhejiang University Science, Vol. 8, No. 11, 2007, pp. 792-801.
 T. M. Gireesha, H. E. Shashidhar and S. Hittalmani, “Genetics of root morphology and related traits in an indica-indica based mapping population of rice (Oryza sativa L.)”, Research on Crops, Vol. 1, 2000, pp.208-215.
 S. P. Mane, H. E. Shashidhar, A. Kanbar and S. Hittalmani, “Molecular marker analysis for root length in a diverse germplasm of rice (Oryza sativa L.)”, Indian Journal of Genetics, Vol. 63, No.3, 2003, pp. 197-201.
 F. Asch, M. Dingkuhn, A. Sow and A. Audebert, “Drought-induced changes in rooting patterns and assimilate partitioning between root and shoot in upland rice”, Field Crops Research, Vol. 93, 2005, pp. 223-236.
 C. G. Xu, X. Q. Li, Y. Xue, Y. W. Huang, J. Gao and Y. Z. Xing, “Comparison of quantitative trait loci controlling seedling characteristics at two seedling stages using rice recombinant inbred lines”, Theoretical and Applied Genetics, Vol. 109, 2004, pp.640-647.
 A. H. Price, K. A. Steele, B. J. Moore, P. B. Barraclough and L. J. Clark, “A combined RFLP and AFLP linkage map of upland rice (Oryza sativa L.) used to identify QTLs for root-penetration ability”, Theoretical and Applied Genetics, Vol. 100, 2000, pp.49-56.
 A. Kathiresan, H.R. Lafitte, J. Chen, L. Mansueto, R . Bruskiewich and J. Bennett, “Gene expression microarrays and their application in drought stress research”, Field Crops Research, Vol. 97, 2006, pp. 101-110.
 M. A. Rabbani, K. Maruyama, H. Abe, A. Khan, K. Katsura, Y. Ito, K. Yoshiwara, M. Seki, K. Shinozaki, Yamaguchi and K. Shinozaki, “Monitoring expression profiles of rice genes under cold, drought and high-salinity stresses and abscisic acid application using cDNA microarray and RNA gel-blot analyses”, Plant Physiology, Vol. 133, 2003, pp.1755-1767.
 G. H. Salekdeh, J. Siopongco, L. J. Wade, B. Ghareyazie and J. Bennett, “A proteomic approach to analyzing drought and salt responsiveness in rice”, Field Crops Research, Vol. 76, 2002, pp. 199-219.
 M. Rodriguez, E. Canales, C. J. Borroto, E. Carmona, J. Lopez, M. Pujol and O Borras-Hidalgo, “Identification of genes induced upon water-deficit stress in a drought- tolerant rice cultivar” Journal of Plant Physiology, Vol. 163, 2006, pp. 577-584
 A. R. Rabello, C. M. Guimaraes, P. H. N. Rangel, F. R. Silva, D. Seixas, E. D. Souza, A. C. M. Brasileiro, C. R. Spehar, M. E. Ferreira and A. Mehta, “Identification of drought-responsive genes in roots of upland rice (Oryza sativa L)” BMC Genomics, Vol. 9, 2008, pp. 485
 A. Kamoshita, J. X. Zhang, J. Siopongco, S. Sakarung, H. T. Nguyen and L. J. Wade, “Effects of phenotyping environment on identification of quantitative trait loci for rice root morphology under anaerobic conditions”, Crop Science, Vol. 42, 2002b, pp. 255-265.
 W. P. Zhang, X. Y. Shen, P. Wu, B. Hu and C. Y. Liao, “QTLs and epistasis for seminal root length under a different water supply in rice (Oryza sativa L.)”, Theoretical and Applied Genetics, Vol.103, 2001b, pp. 118-123.
 K. MacMillan, K. Emrich, H. P. Piepho, C. E. Mullins and A. H. Price, “Assessing the importance of genotype × environment interaction for root traits in rice using a mapping population II: conventional QTL analysis” Theoretical and Applied Genetics, Vol. 113: 2006, pp. 953-964.
 S. B. Yu, J. X. Li, C. G. Xu, Y. F. Tan, Y. J. Gao, X. H .Li, Q. Zhang and M. A. Saghai Maroof, “Importance of epistasis as the genetic basis of heterosis in an elite rice hybrid”, Proceedins of the National Academy of Sciences, USA, Vol. 94, No.17, 1997, pp.9226-9231.
 Z. K. Li, L. J. Luo, H. W. Mei, Q.Y. Shu, D. L. Wang, R. Tabien, D. B. Zhong, C. S. Ying, J. W. Stancel, G. S. Khush and A. H. Paterson, “Overdominant epistatic loci are the primary genetic basis of inbreeding depression and heterosis in Rice: I Biomass and grain yield”, Genetics Vol. 158, 2001, pp.1737-1753.
 Y. Z. Xing, Y. F. Tan, J.P. Hua, X. L. Sun, C. G. Xu and Q. Zhang, “Characterization of the main effects epistatic effects and their environmental interactions of QTLs on the genetic basis of yield traits in rice” Theoretical and Applied Genetics, Vol. 105, 2002, pp. 248-257.
 C. Brondani, P. H. N. Rangel, R. P. V. Brondani and M. E. Ferreira, “QTL mapping and introgression of yield- related traits from Oryza glumaepetula to cultivated rice (Oryza sativa L). using microsatellite makers”, Theoretical and Applied Genetics, Vol. 104, 2002, pp. 1192-1203.
 S. R. McCouch, M. Sweeney, J. Li, H. Jiang, M. Thomson, E. Septiningsih, J. Edwards, P. Moncada, J. Xiao, A. Garris, T. Tai, C. Martinez, J. Tohme, M. Sugiono, A. McClung, L. P. Yuan and S. N. Ahn, “Through the genetic bottleneck: O. rufipogon as a source of trait-enhancing alleles for O. sativa L.” Euphytica, Vol. 154, 2007, pp. 317-339.