Submitted to: Plant and Soil
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/22/2005
Publication Date: 7/1/2006
Citation: Ma, H., Bai, G., Lu, W.Z. 2006. Quantitative trait loci for Aluminum resistance in wheat cultivar Chinese Spring. Plant and Soil Journal 283:239-249 Interpretive Summary: Aluminum (Al) toxicity is one of the major limiting factors for wheat production in acid soils. The objective of this study was to locate wheat genes for Al-tolerance on wheat chromosomes and identify molecular markers linked to the genes for marker-assisted breeding. Chinese Spring is a moderately tolerant wheat cultivar. A set of lines of Chinese Spring with one chromosome arm removed in each line was assessed for Al tolerance. Lines Dt5AL, Dt7AL, Dt2DS and Dt4DS were significantly more sensitive to Al stress than that of original Chinese Spring, suggesting that the Al-tolerance genes might be on the missing chromosome arms 5AS, 7AS, 2DL and 4DL. Three genes - Qalt.ksu-4D, Qalt.ksu-5A and Qalt.ksu-2D - enhanced root growth under Al stress. The gene on 4DL of Chinese Spring is most likely the same gene identified in Atlas 66, but a different allele. Some DNA markers identified in this study would be useful for marker-assisted pyramiding of different genes for Al tolerance in wheat cultivars.
Technical Abstract: Aluminum (Al) toxicity is one of the major constrains for wheat production in many wheat growing areas worldwide. Further understanding of inheritance of Al tolerance may facilitate improvement of Al tolerance of wheat cultivars (Triticum aestivum L.). A set of ditelosomic lines derived from the moderately Al-tolerant wheat cultivar Chinese Spring was assessed for Al tolerance. The root growth of ditelosomic lines Dt5AL, Dt7AL, Dt2DS and Dt4DS was significantly lower than that of euploid Chinese Spring under Al stress, suggesting that Al-tolerance genes might exist on the missing chromosome arms of 5AS, 7AS, 2DL and 4DL of Chinese Spring. A population of recombinant inbred lines (RILs) from the cross Annong 8455 x Chinese Spring-Sumai 3 7A substitution line was used to determine the effects of these chromosome arms on Al tolerance. A genetic linkage map consisting of 410 amplified fragment length polymorphism (AFLP) markers and 168 simple sequence repeat (SSR) markers was constructed to determine the genetic effect of the quantitative trait loci (QTLs) for Al tolerance in Chinese Spring. Three QTLs, Qalt.ksu-4D, Qalt.ksu-5A and Qalt.ksu-2D, were identified that enhanced root growth under Al stress, suggesting that inheritance of Al tolerance in Chinese Spring is polygenic. The QTL with the largest effect was flanked by the markers of Xwmc331 and Xcfd84 on chromosome 4DL and most probably is allelic to the major QTL identified in Atlas 66. Two additional QTLs, Qatl.ksu-5A and Qatl.ksu-2D on chromosome 5AS and 2DL, respectively, were also detected with marginal significance in the population. Some SSR markers identified in this study would be useful for marker-assisted pyramiding of different QTL for Al tolerance in wheat cultivars