To identify and develop drought tolerant maize ( Zea mays L.), high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and their hybrid testcross progeny were evaluated for germination, survival and recovery after a series of drought cycles. Genotypic differences among inbred lines and hybrid testcrosses were best explained approximately 13 and 18 days after planting, respectively. Genotypic effects were significant and explained over 6% of experimental variance. Specifically three inbred lines had significant survival, and 14 hybrids had significant recovery. However, no significant correlation was observed between hybrids and inbreds ( R 2 = 0.03), indicating seedling stress response is more useful as a secondary screening parameter in hybrids than in inbred lines per se. Field yield data under full and limited irrigation indicated that seedling drought mechanisms were independent of drought responses at flowering in this study.
References
[1]
Battisti, D.S.; Naylor, R.L. Historical warnings of future food insecurity with unprecedented seasonal heat. Science？2009, 323, 240–244, doi:10.1126/science.1164363.
[2]
Lobell, D.B.; Schlenker, W.; Costa-Roberts, J. Climate trends and global crop production since 1980. Science？2011, 333, 616, doi:10.1126/science.1204531.
[3]
Mishra, V.; Cherkauer, K.A. Retrospective droughts in the crop growing season: Implications to corn and soybean yield in the midwestern united states. Agric. For. Meteorol.？2010, 150, 1030–1045, doi:10.1016/j.agrformet.2010.04.002.
[4]
Campos, H.; Cooper, M.; Habben, J.; Edmeades, G.; Schussler, J. Improving drought tolerance in maize: A view from industry. Field Crops Res.？2004, 90, 19–34, doi:10.1016/j.fcr.2004.07.003.
[5]
Ribaut, J.M.; Betran, J.; Monneveux, P.; Setter, T. Drought tolerance in maize. In Handbook of Maize: Its Biology; Bennetzen, J.L., Hake, S.C., Eds.; Springer: New York, NY, USA, 2009; pp. 311–344.
[6]
Richards, R. Defining selection criteria to improve yield under drought. Plant Growth Regul.？1996, 20, 157–166, doi:10.1007/BF00024012.
[7]
Obeng-Bio, E.; Bonsu, M.; Obeng-Antwi, K.; Akromah, R. Establishing the basis for drought tolerance in maize (Zea mays l.) using some secondary traits in the field. Afr. J. Plant Sci.？2011, 5, 702–709.
[8]
Bruce, W.B.; Edmeades, G.O.; Barker, T.C. Molecular and physiological approaches to maize improvement for drought tolerance. J. Exp. Bot.？2002, 53, 13–25, doi:10.1093/jexbot/53.366.13.
[9]
Betran, F.; Beck, D.; B？nziger, M.; Edmeades, G. Secondary traits in parental inbreds and hybrids under stress and non-stress environments in tropical maize. Field Crops Res.？2003, 83, 51–65, doi:10.1016/S0378-4290(03)00061-3.
[10]
Bolanos, J.; Edmeades, G. The importance of the anthesis-silking interval in breeding for drought tolerance in tropical maize. Field Crops Res.？1996, 48, 65–80, doi:10.1016/0378-4290(96)00036-6.
[11]
Ludlow, M.; Muchow, R. A critical evaluation of traits for improving crop yields in water-limited environments. Adv. Agron.？1990, 43, 107–153, doi:10.1016/S0065-2113(08)60477-0.
Muenchrath, D.A. Morphological and physiological characterization of a desert adapted traditional native american maize (zea mays l.) cultivar. Ph.D. thesis, Iowa State University, Ames, IA, USA, 1995.
[14]
B？nziger, M.; Setimela, P.; Hodson, D.; Vivek, B. Breeding for improved drought tolerance in maize adapted to southern africa. Agric. Water Manage.？2006, 80, 212–214, doi:10.1016/j.agwat.2005.07.014.
[15]
Singh, B.; Mai-Kodomi, Y.; Terao, T. A simple screening method for drought tolerance in cowpea. Indian J. Genet. Plant Breed.？1999, 59, 211–220.
[16]
Ristic, Z.; Jenks, M.A. Leaf cuticle and water loss in maize lines differing in dehydration avoidance. J. Plant Physiol.？2002, 159, 645–651, doi:10.1078/0176-1617-0743.
[17]
Meeks, M.; Murray, S.; Hague, S.; Hays, D.; Ibrahim, A. Genetic variation for maize epicuticular wax response to drought stress at flowering. J. Agron. Crop Sci.？2012, 198, 161–172, doi:10.1111/j.1439-037X.2011.00495.x.
[18]
Collins, N.C.; Tardieu, F.; Tuberosa, R. Quantitative trait loci and crop performance under abiotic stress: Where do we stand? Plant Physiol.？2008, 147, 469–486, doi:10.1104/pp.108.118117.
[19]
B？nziger, M.; Araus, J.L. Recent advances in breeding maize for drought and salinity stress tolerance. In Advances in Molecular Breeding toward Drought and Salt Tolerant Crops; Jenks, M.A., Hasegawa, P.M., Jain, S.M., Eds.; Springer: Dordrecht, Netherlands, 2007; pp. 587–601.
[20]
Singh, B.B.; Matsui, T. Cowpea varieties for drought tolerance. In Challenges and Opportunities for Enhancing Sustainable Cowpea Production, Proceedings of the World Cowpea Conference III Held at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, 4–8 September 2000; Fatokun, C.A., Tarawali, S.A., Singh, B.B., Kormawa, P.M., Tamò, M., Eds.; IITA: Ibadan, Nigeria, 2002; pp. 287–300.
[21]
Longenberger, P.S.; Smith, C.; Thaxton, P.; McMichael, B. Development of a screening method for drought tolerance in cotton seedlings. Crop Sci.？2006, 46, 2104–2110, doi:10.2135/cropsci2006.01.0026.
[22]
Tomar, S.; Kumar, G. Seedling survivability as a selection criterion for drought tolerance in wheat. Plant Breed.？2004, 123, 392–394, doi:10.1111/j.1439-0523.2004.00993.x.
[23]
Banziger, M.; Edmeades, G.; Quarrie, S. Drought stress at seedling stage-are there genetic solutions? In Proceedings of a Symposium, El Batan, Mexico, 25–29 March 1996; CIMMYT: El Batan, Mexico, 1997.
[24]
Xu, W.; Odvody, G.; Williams, W.P. Tx204 and Tx205 inbred lines. Germplasm Enhancement of Maize (GEM). Annual Report; USDA-ARS: Lubbock, TX, USA, 2004. Available online: http://www.public.iastate.edu/~usda-gem/GEM_Annual_Reports/GEM_AR_04.htm#SCA (accessed on 6 February 2013).
[25]
Singh, B.; Matsui, T. Cowpea varieties for drought tolerance. In Challenges and Opportunities for Enhancing Sustainable Cowpea Production; IITA: Ibadan, Nigeria, 2002; pp. 287–300.
[26]
Betrán, F.; Fojt, A.; Mayfield, F.; K Pietsch, D. Registration of Tx714 maize germplasm line. Crop Sci.？2004, 44, 1028, doi:10.2135/cropsci2004.1028.
[27]
Betrán, F.J.; Bockholt, A.; Fojt, F.; Mayfield, K. Registration of Tx732 maize germplasm line. Crop Sci.？2004, 44, 1028–1029, doi:10.2135/cropsci2004.1028.
[28]
Betrán, F.J.; Bockholt, A.; Fojt, F.; Mayfield, K. Registration of Tx770 maize germplasm line. Crop Sci.？2004, 44, 1029–1030, doi:10.2135/cropsci2004.1029.
[29]
Llorente, C.; Fojt, F.; Bockholt, A.; Betrán, F. Registration of Tx772 maize. Crop Sci.？2004, 44, 1036–1037, doi:10.2135/cropsci2004.1036.
[30]
Hallauer, A.R.; Lamkey, K.R.; White, P.R. Registration of five inbred lines of maize: B102, B103, B104, B105, and B106. Crop Sci.？1997, 37, 1405–1406, doi:10.2135/cropsci1997.0011183X003700040094x.
[31]
Russell, W. Registration of B70 and B73 parental lines of maize (reg. Nos. Pl16 and pl17). Crop Sci.？1972, 12, 721–721, doi:10.2135/cropsci1972.0011183X001200050085x.
[32]
Foley, T.J. Inbred corn line LH195. U.S. Patent No. 5,059,745, 22 October 1991.
[33]
Foley, T.J. Inbred corn line LH287. U.S. Patent No. 6,281,414, 28 August 2001.
