Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Aluminum (Al) tolerance is an important trait for crops grown on acidic soils. The range of Al tolerance variation in wheat (Triticum aestivum L.) suggests that multiple Al tolerance loci exist, and we are conducting studies to gain insights into the issue of Al tolerance gene diversity in this species. Analysis of the mechanism of Al tolerance associated with AltBH, a major Al tolerance gene in cv BH1146, suggests that it confers Al tolerance by exudation of malate from the root apex. Thus AltBH is likely to be the same allele as Alt1, an Al tolerance gene from cv Carazinho associated with this same mechanism of tolerance. Physical mapping of Alt2, an Al tolerance gene in the less Al-tolerant cv Chinese Spring, indicates that it is likely to be an alternative allele of the AltBH/Alt1 locus rather than a unique gene. A study of Al-tolerant NILs of the cvs Century and Chisholm that each harbor a single Al tolerance gene from Atlas 66 indicates both incomplete transfer of Al tolerance and reduced root tip malate release relative to Atlas 66. Taken together, these data indicate that Al tolerance variation in wheat as a whole may be due to both allelic variation and multiple loci. However, this variation appears to be associated with a single physiological mechanism of Al tolerance (root tip malate release), rather than different mechanisms. Therefore, it may be possible to pyramid different Al tolerance genes to enhance Al tolerance in wheat.