Location: Hard Winter Wheat Genetics ResearchTitle: Diverse Origins of Aluminum-resistant Sources in Wheat Author
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2008
Publication Date: 9/10/2008
Citation: Hu, S., Bai, G., Carver, B., Zhang, D. 2008. Diverse Origins of Aluminum-resistant Sources in Wheat. Theoretical and Applied Genetics. DOI 10.1007/500122-008-0874-4. Interpretive Summary: In acidic soils, a large amount of free aluminum (Al) may be released into soil solution. This affects wheat root growth and subsequently reduces nutrient and water uptake essential for plant growth. Use of Al-resistant cultivars can significantly reduce risks associated with acidic soils. In this study, 57 wheat accessions were classified into four groups: US-Fultz, Polyssu, Mexican and Chinese, based on their DNA markers and pedigree. The result indicated that Al resistance in the four groups may have three independent origins. Fultz was developed in the USA as a major ancestor to soft red winter wheat, Polyssu originated in Brazil as a major source of Al resistance used in most genetic studies worldwide, and the Chinese group originated in China. Al resistance in US cultivars is mainly from Fultz, not from Polyssu. Further characterization of Al resistance in the three different sources could reveal multiple Al-resistant mechanisms in wheat.
Technical Abstract: Aluminum (Al) toxicity is a major constraint for wheat production in acidic soils. Wheat producers now routinely use Al-resistant cultivars as one cost-effective means to reduce risks associated with acidic soils. To date, diverse Al-resistant materials have been identified, but their genetic relationship has not been well characterized. Fifty-seven wheat accessions, including the majority of the parents of Al-resistant accessions we identified in a previous study, were evaluated for Al resistance and analyzed with 49 simple sequence repeat (SSR) markers and 4 markers for Al-activated malate transporter (ALMT1). Pedigree and principal coordinate analysis (PCA) both separated Al-resistant accessions into four groups labeled according to common ancestry or geographical origin: US-Fultz, Polyssu, Mexican and Chinese. Al resistance in the four groups may have three independent origins given their distinct geographic origin and gene pools. Fultz originated in the USA as a major ancestor to soft red winter wheat, Polyssu originated in Brazil as a major source of Al resistance used in most genetic studies worldwide, and the Chinese group originated in China. Based on ALMT1 marker haplotypes, the Al resistance in the Mexico group was likely derived from Polyssu, while most Al-resistant cultivars developed in the USA most likely inherited Al resistance from Fultz. Fultz was released about 50 years earlier than Polyssu. Norin 10 likely played a pivotal role in passing Al-resistant gene(s) from Fultz to better adapted, semi-dwarf wheat cultivars developed in the USA and at CIMMYT, Mexico. Further characterization of Al resistance in the three different sources could reveal multiple Al-resistant mechanisms in wheat.