ARS | Publication request: Selecting and Sorting Waxy Wheat Kernels Using Near-Infrared Spectroscopy

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 6, 2009
Publication Date: May 1, 2009
Repository URL: http://ars.usda.gov/Services/docs.htm?docid=18151
Citation: Dowell, F.E., Maghirang, E.B., Graybosch, R.A., Berzonsky, W.A., Delwiche, S.R. 2009. Selecting and Sorting Waxy Wheat Kernels Using Near-Infrared Spectroscopy. Cereal Chemistry. 86(3):251-255.

Interpretive Summary: Amylose-free, or waxy, wheat has functional end-use advantages over amylose-bearing wheat, and these advantages can provide for additional marketing opportunities. For example, waxy wheat flour has a high water-binding capacity, products made from waxy flour can exhibit a longer shelf-life, products extruded from waxy flour can be enhanced, and ethanol conversion from waxy wheat is enhanced. However, when developing waxy wheat as few as 1 in 64 kernels may express the waxy trait. Therefore, the ability to select waxy seed from early generation segregating populations would provide breeding materials enriched in the number of seeds with this trait. Also, if an advanced waxy breeding line requires purification for the waxy trait prior to release, there is presently no efficient or cost-effective way to accomplish this, especially since large seed samples are typically involved. We showed at an automated single-kernel near-infrared (SKNIR) sorting system could be used to select waxy kernels from segregating breeding lines or to purify advance breeding lines for the waxy trait. This rapid and non-destructive SKNIR technology offers significant benefits to breeding program and is much faster than utilizing molecular markers or staining techniques.

Technical Abstract: An automated single kernel near-infrared (NIR) sorting system was used to separate single wheat (Triticum aestivum L.) kernels with amylose-free (waxy) starch from reduced-amylose (partial waxy) or wild-type wheat kernels. Waxy kernels of hexaploid wheat are null for the granule-bound starch synthase alleles at all three Wx gene loci; whereas, partial-waxy kernels have at least one null and one functional allele. Wild-type kernels have three functional alleles. Our results demonstrate that automated single kernel NIR technology can be used to select waxy kernels from segregating breeding lines or to purify advance breeding lines for the low-amylose kernel trait. Calibrations based on either amylose content or the waxy trait performed similarly. Also, a calibration developed using the amylose content of waxy, partial waxy, and wild-type durum (T. turgidum L. var durum) wheat enabled adequate sorting for hard red winter and hard red spring wheat with no modifications. Regression coefficients indicated that absorption by starch in the NIR region contributed to classification models. Single kernel NIR technology offers significant benefits to breeding programs developing wheat with amylose-free starches.