AOBPreview originally published online on April 30, 2007
Annals of Botany 2007 99(6):1067-1081; doi:10.1093/aob/mcm055
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INVITED REVIEW |
Mapping of QTL Associated with Waterlogging Tolerance during the Seedling Stage in Maize
College of Plant Science and Technology, National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
* For correspondence. E-mail shangzhongxu{at}gmail.com
Received: 26 November 2006 Returned for revision: 10 January 2007 Accepted: 12 February 2007 Published electronically: 30 April 2007
Background and Aims: Soil waterlogging is a major environmental stress that suppresses maize (Zea mays) growth and yield. To identify quantitative trait loci (QTL) associated with waterlogging tolerance at the maize seedling stage, a F2 population consisting of 288 F2:3 lines was created from a cross between two maize genotypes, HZ32 (waterlogging-tolerant) and K12 (waterlogging-sensitive).
Methods: The F2 population was genotyped and a base-map of 1710·5 cM length was constructed with an average marker space of 11·5 cM based on 177 SSR (simple sequence repeat) markers. QTL associated with root length, root dry weight, plant height, shoot dry weight, total dry weight and waterlogging tolerance coefficient were identified via composite interval mapping (CIM) under waterlogging and control conditions in 2004 (EXP.1) and 2005 (EXP.2), respectively.
Key Results and Conclusions: Twenty-five and thirty-four QTL were detected in EXP.1 and EXP.2, respectively. The effects of each QTL were moderate, ranging from 3·9 to 37·3 %. Several major QTL determining shoot dry weight, root dry weight, total dry weight, plant height and their waterlogging tolerance coefficient each mapped on chromosomes 4 and 9. These QTL were detected consistently in both experiments. Secondary QTL influencing tolerance were also identified and located on chromosomes 1, 2, 3, 6, 7 and 10. These QTL were specific to particular traits or environments. Although the detected regions need to be mapped more precisely, the findings and QTL found in this study may provide useful information for marker-assisted selection (MAS) and further genetic studies on maize waterlogging tolerance.
Key words: Maize (Zea mays), waterlogging tolerance, genome mapping, SSR marker, QTL, epistasis effect