Marker-assisted breeding for TaALMT1, a major gene conferring aluminium tolerance to wheat

• Published in: Biologia plantarum Vol. 59; no. 1; pp. 83 - 91
• Main Authors: Soto-Cerda, B. J, Inostroza-Blancheteau, C, Mathías, M, Peñaloza, E, Zuñiga, J, Muñoz, G, Rengel, Z, Salvo-Garrido, H
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.01.2015; Springer Netherlands; Institute of Experimental Botany of the Czech Academy of Sciences
• Subjects: acid soils; aluminum; backcross lines; backcrossing; Biomedical and Life Sciences; chromosomes; crop production; cultivars; gene expression; genes; genetic markers; homozygosity; hydroponics; introgression; Life Sciences; malate transporter; malates; marker-assisted selection; metal tolerance; microsatellite markers; Original Papers; Plant Sciences; quantitative trait loci; sequence analysis; Triticum aestivum; wheat; Chile; acid soils; microsatellite markers; introgression; gene expression; malate transporter; backcross lines
• ISSN: 0006-3134; 1573-8264
• DOI: 10.1007/s10535-014-0474-x

Aluminium toxicity in acid soils is the main limitation to crop production worldwide. In wheat (Triticum aestivum L.), the Al-activated malate transporter (TaALMT1) gene located on chromosome 4DL is associated with malate efflux and Al-tolerance. To introgress Al-tolerance from the breeding line CAR3911 into the high yielding Al-sensitive cultivar Kumpa-INIA, phenotypic and molecular characterizations of gene/QTL underlying Al-tolerance in CAR3911 followed by marker-assisted backcrossing (MAS-BC) were undertaken. Al-tolerant backcross (BC) lines were selected using the functional marker ALMT1-4 designed immediately upstream of the TaALMT1 coding region. Foreground and background selections using ALMT1-4 and microsatellite markers were conducted. Linkage and sequence analyses suggest that the TaALMT1 gene could underly the Al-tolerance in CAR3911, possessing the same promoter type (V) as the Al-tolerant genotypes Carazinho and ET8. The MAS-BC strategy allowed the selection of Al-tolerant lines with the smallest introgressed region (6 cM) on 4D and the highest recurrent parent genome (RPG) (98 %) covering 2 194 cM of the wheat genome. The homozygous BC3F2 line named Kumpa-INIA-TaALMT1 expressed a 3-fold higher Al-tolerance than its isogenic line Kumpa-INIA at 40 μM Al in the hydroponic solution, and similarly to CAR3911 and Carazinho. The MAS-BC strategy was successful for the introgression of the TaALMT1 gene into Kumpa-INIA in only three BC generations, shortening the breeding cycle to 24 months, which promises to increase wheat production and a greater yield stability in the acid soils of Southern Chile.