Author
CAI, SHI-BIN - KANSAS STATE UNIVERSITY | |
Bai, Guihua | |
ZHANG, DADONG - KANSAS STATE UNIVERSITY |
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/14/2008 Publication Date: 7/1/2008 Citation: Cai, S., Bai, G., Zhang, D. 2008. Quantitative Trait Loci for Aluminum Resistance in Chinese Wheat Landrace FSW. Theoretical and Applied Genetics. 117:49-56. Interpretive Summary: Aluminum (Al) toxicity is a major problem for wheat production in acid soils. Chinese landrace FSW shows a high level of Al resistance. Quantitative trait loci (QTLs) controlling Al resistance were identified in FSW through evaluating net root growth (NRG) in a nutrient solution culture containing Al3+ and hematoxylin staining score (HSS) of roots after Al stress. Molecular marker analysis identified three QTLs to control Al resistance in FSW. They were located on chromosomes, 4DL, 3BL and 2A, respectively. Together, the three QTLs accounted for up to 81.9% of the variation for HSS and 78.3% of the variation for NRG. The QTL on 3BS is a novel QTL with a large effect on Al resistance discovered in this study. The two major QTLs on 4DL and 3BL demonstrated an additive effect. The SSR markers closely linked to the QTLs have potential to be used for marker-assisted selection to improve Al resistance of wheat cultivars in breeding programs. Technical Abstract: Aluminum (Al) toxicity is a major constraint for wheat production in acid soils worldwide. Chinese landrace FSW demonstrates a high level of Al resistance. A population of 170 F6 recombinant inbred lines (RILs) was developed from a cross between FSW and an Al-sensitive Chinese line, ND35, using single seed descent, to map quantitative trait loci (QTLs) for Al resistance. Wheat reaction to Al stress was measured by net root growth (NRG) in a nutrient solution culture containing Al3+ and hematoxylin staining score (HSS) of root after Al stress. After 1,437 simple sequence repeats (SSRs) were screened using bulk segregant analysis, three QTLs were identified to control Al resistance in FSW. One major QTL was mapped on chromosome 4DL that co-segregated with Xups4, a marker for the promoter of the Al-activated malate transporter (ALMT1) gene. The other two QTLs were located on chromosomes 3BL and 2A, respectively. Together, the three QTLs accounted for up to 81.9% of the phenotypic variation for HSS and 78.3% of the variation for NRG. The physical positions of flanking markers for the QTLs on 4DL and 3BL were determined by analyzing these markers in corresponding nulli-tetrasomic, ditelosomic, and 3BL deletion lines of Chinese Spring. The QTL on 3BS is a novel QTL with a major effect on Al resistance discovered in this study. The two major QTLs on 4DL and 3BL demonstrated an additive effect. The SSR markers closely linked to the QTLs have potential to be used for marker-assisted selection to improve Al resistance of wheat cultivars in breeding programs. |