Harris, K. and Subudhi, P.K. and Borrell, A. and Jordan, D. and Rosenow, D. and Nguyen, H. and Klein, P. and Klein, R. and Mullet, J. (2007) Sorghum stay-green QTL individually reduce post-flowering drought-induced leaf senescence. Journal of Experimental Botany, 58 (2). pp. 327-338.
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Abstract
Sorghum is an important source of food, feed, and biofuel, especially in the semi-arid tropics because this cereal is well adapted to harsh, drought-prone environments. Post-flowering drought adaptation in sorghum is associated with the stay-green phenotype. Alleles that contribute to this complex trait have been mapped to four major QTL, Stg1-Stg4, using a population derived from BT × 642 and RT × 7000. Near-isogenic RT × 7000 lines containing BT × 642 DNA spanning one or more of the four stay-green QTL were constructed. The size and location of BT × 642 DNA regions in each RT × 7000 NIL were analysed using 62 DNA markers spanning the four stay-green QTL. RT × 7000 NILs were identified that contained BT × 642 DNA completely or partially spanning Stg1, Stg2, Stg3, or Stg4. NILs were also identified that contained sub-portions of each QTL and various combinations of the four major stay-green QTL. Physiological analysis of four RT × 7000 NILs containing only Stg1, Stg2, Stg3, or Stg4 showed that BT × 642 alleles in each of these loci could contribute to the stay-green phenotype. RT × 7000 NILs containing BT × 642 DNA corresponding to Stg2 retained more green leaf area at maturity under terminal drought conditions than RT × 7000 or the other RT × 7000 NILs. Under post-anthesis water deficit, a trend for delayed onset of leaf senescence compared with RT × 7000 was also exhibited by the Stg2, Stg3, and Stg4 NILs, while significantly lower rates of leaf senescence in relation to RT × 7000 were displayed by all of the Stg NILs to varying degrees, but particularly by the Stg2 NIL. Greener leaves at anthesis relative to RT × 7000, indicated by higher SPAD values, were exhibited by the Stg1 and Stg4 NILs. The RT × 7000 NILs created in this study provide the starting point for in-depth analysis of stay-green physiology, interaction among stay-green QTL and map-based cloning of the genes that underlie this trait
| Item Type: | Article |
|---|---|
| Author Affiliation: | Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA |
| Subjects: | Crop Improvement Crop Improvement > Plant Breeding |
| Divisions: | Sorghum |
| Depositing User: | Syamala |
| Date Deposited: | 23 Feb 2011 17:50 |
| Last Modified: | 23 Feb 2011 17:50 |
| Official URL: | http://dx.doi.org/10.1093/jxb/erl225 |
| URI: | http://eprints.icrisat.ac.in/id/eprint/1535 |
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