Raman Harsh, Ryan Peter R, Raman Rosy, Stodart Benjamin J, Zhang Kerong, Martin Peter, Wood Rachel, Sasaki Takayuki, Yamamoto Yoko, Mackay Michael, Hebb Diane M, Delhaize Emmanuel
NSW Department of Primary Industries and NSW Agricultural Genomics Centre, Wagga Wagga Agricultural Institute, Pine Gully Road, Wagga Wagga, NSW, 2650, Australia.
Theor Appl Genet. 2008 Feb;116(3):343-54. doi: 10.1007/s00122-007-0672-4. Epub 2007 Nov 29.
Allele diversities of four markers specific to intron three, exon four and promoter regions of the aluminum (Al) resistance gene of wheat (Triticum aestivum L.) TaALMT1 were compared in 179 common wheat cultivars used in international wheat breeding programs. In wheat cultivars released during the last 93 years, six different promoter types were identified on the basis of allele size. A previous study showed that Al resistance was not associated with a particular coding allele for TaALMT1 but was correlated with blocks of repeated sequence upstream of the coding sequence. We verified the linkage between these promoter alleles and Al resistance in three doubled haploid and one intercross populations segregating for Al resistance. Molecular and pedigree analysis suggest that Al resistance in modern wheat germplasm is derived from several independent sources. Analysis of a population of 278 landraces and subspecies of wheat showed that most of the promoter alleles associated with Al resistance pre-existed in Europe, the Middle East and Asia prior to dispersal of cultivated germplasm around the world. Furthermore, several new promoter alleles were identified among the landraces surveyed. The TaALMT1 promoter alleles found within the spelt wheats were consistent with the hypothesis that these spelts arose on several independent occasions from hybridisations between non-free-threshing tetraploid wheats and Al-resistant hexaploid bread wheats. The strong correlation between Al resistance and Al-stimulated malate efflux from the root apices of 49 diverse wheat genotypes examined was consistent with the previous finding that Al resistance in wheat is conditioned primarily by malate efflux. These results demonstrate that the markers based on intron, exon and promoter regions of TaALMT1 can trace the inheritance of the Al resistance locus within wheat pedigrees and track Al resistance in breeding programmes.
在国际小麦育种计划中使用的179个普通小麦品种中，比较了小麦（Triticum aestivum L.）TaALMT1铝（Al）抗性基因内含子三、外显子四和启动子区域特异性的四个标记的等位基因多样性。在过去93年发布的小麦品种中，根据等位基因大小鉴定出六种不同的启动子类型。先前的一项研究表明，铝抗性与TaALMT1的特定编码等位基因无关，但与编码序列上游的重复序列块相关。我们在三个双单倍体和一个分离铝抗性的杂交群体中验证了这些启动子等位基因与铝抗性之间的连锁关系。分子和系谱分析表明，现代小麦种质中的铝抗性来自几个独立的来源。对278个小麦地方品种和亚种群体的分析表明，与铝抗性相关的大多数启动子等位基因在栽培种质传播到世界各地之前就已存在于欧洲、中东和亚洲。此外，在调查的地方品种中还鉴定出几个新的启动子等位基因。在斯佩尔特小麦中发现的TaALMT1启动子等位基因与这些斯佩尔特小麦是在非自由脱粒四倍体小麦和抗铝六倍体面包小麦之间的几次独立杂交中产生的假设一致。在检测的49种不同小麦基因型的根尖中，铝抗性与铝刺激的苹果酸外排之间的强相关性与先前的发现一致，即小麦中的铝抗性主要由苹果酸外排决定。这些结果表明，基于TaALMT1内含子、外显子和启动子区域的标记可以追踪小麦系谱中铝抗性基因座的遗传，并在育种计划中追踪铝抗性。
