Skip to main content
ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #118867
Title: GENETIC AND PHYSICAL MAPPING OF A MAJOR GENE FOR ALUMINUM TOLERANCE IN WHEAT (TRITICUM AESTIVUM L. EM THELL.)

Author
item RODRIGUEZ MILLA, M - UNIV OF MISSOURI-COLUMBIA
item Gustafson, J

Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2001
Publication Date: 10/1/2001
Citation: RODRIGUEZ MILLA, M.A., GUSTAFSON, J.P. GENETIC AND PHYSICAL MAPPING OF A MAJOR GENE FOR ALUMINUM TOLERANCE IN WHEAT (TRITICUM AESTIVUM L. EM THELL.). GENOME. 2001. V. 44(5). P. 883-892.

Interpretive Summary: Aluminum is the most abundant metal on earth and is highly toxic to plant growth. There are about 2.5 billion hectares of acid soils high in aluminum around the world, including several million in the United States. The present study was designed to map the location of the gene(s) controlling aluminum tolerance in wheat and establish molecular markers flanking the gene(s). These molecular markers will be of considerable value in a marker-mediated breeding program designed to improve the aluminum tolerance levels existing in many wheat cultivars. The results of the study are: (1) we mapped the major gene in wheat to the long arm of chromosome 4D (2) we established molecular markers flanking the gene, and (3) we physically mapped the gene to a region on the long arm of chromosome 4D. The impact of this research will not only be on breeders developing aluminum-tolerant varieties via marker-assisted selection, but results will lalso be of value to scientists attempting to clone the gene(s) for aluminu tolerance in wheat.

Technical Abstract: Different studies have clearly demonstrated that aluminum (Al) tolerance in wheat is genetically controlled and involves several genes. A major gene on the long arm of chromosome 4D plays a major role. Molecular markers have been associated with a gene on this chromosome in Chinese Spring (Alt2) and most importantly, in the Brazilian cultivar BH 1146 (AltBH), which has one of the highest levels of Al tolerance in hexaploid wheat. We constructed partial linkage map of chromosome arm 4DL in BH 1146, delimiting the AltBH gene to a 5.9 cM interval between markers Xgdm125 and Xpsr914, and confirmed that it maps to the same location as Alt2. Most importantly, the marker Xbcd1230 cosegregated with the AltBH gene in a population of 91 recombinant inbred lines. A set of primers that amplified a portion of this clone was designed for use in mapping large populations or screening large- insert libraries. In addition, utilizing a set of wheat deletion lines for chromosome arm 4DL, the AltBH gene was physically mapped to the distal region of the chromosome between deletion breakpoints 0.70 and 0.86. AFLP- based bulked segregant analysis failed to identify markers tightly linked to the gene and SSR analysis revealed extremely low levels of polymorphism in this genomic region. The implications of these results for marker- assisted selection and map-based cloning approaches are discussed.