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Wheat varietal identification and genetic analysis by reversed-phase high-performance liquid chromatography

Bietz, J.A., Burnouf, T., Cobb, L.A., Wall, J.S.
Cereal chemistry 1984 v.61 no.2 pp. 129
Triticum aestivum, wheat, varieties, cultivars, cultivar identification, reversed-phase high performance liquid chromatography, gliadin, hard red spring wheat, hard red winter wheat, soft red winter wheat, Triticum turgidum subsp. durum, durum wheat
Gliadins are a heterogenous group of alcohol-soluble wheat endosperm storage proteins whose composition varies among wheat genotypes. Reversed-phase (RP) HPLC on large-pore columns gives high-resolution separations of gliadins from extracts of wheats, thereby permitting varietal identification and complementing other methods. Gliadins, extracted with 70% ethanol from single kernels or from bulk samples, are injected onto a reversed-phase (C18) column having 30 nm pores. The proteins are eluted with a gradient of increasing acetonitrile concn. and are detected at 210 nm. Resulting chromatograms reveal approx. 30-40 components. Examples are presented that demonstrate that significant qualitative and quantitative differences occur between nearly all hard red winter, hard red spring, soft red winter, white, and durum wheats examined; only var. having nearly identical pedigrees may be impossible to differentiate. Analysis of aneuploids permits detn. of the chromosomal locations of genes that code proteins eluting in each chromatographic peak, thus establishing markers for the chromosomes. Analysis of phenotypic variants from a sample also permits detection of different genotypes, biotypes, or other off-types. RP-HPLC is fast, sensitive, exhibits good run-to-run reproducibility, has high resolving power, and is easily automated; the ability to accurately quantitate data may facilitate computer-assisted chromatographic comparisons. RP-HPLC of gliadins can be a valuable tool for identification, selection, and comparison of genotypes in breeding and genetic studies.