Comparison of Methods for Amylose Screening Among Maize Starches from Exotic Backgrounds

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Nurtay Abdubeck and Brandy Fuller.
Dr. Mark Campbell, Faculty Mentor.

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Breeding for high-amylose corn requires a rapid method for determining starch amylose so that generating chemistry values does not pose a major limitation in the volume of materials to be screened. Two recently described methods, one an iodine-based technique involving solubilizing ground whole corn in DMSO and one based on near-infrared transmittance spectroscopy (NITS) were compared to an older techniques known as the Williams’ method. The NITS method showed poor correlation to the Williams’ method (r=0.88) however it did appear to discriminate corn having possessing the ae allele versus those having a normal or possibly segregating endosperm type. The DMSO-iodine method showed a much better correlation (r=0.92) and appeared to better discriminate among samples having amylose values >65% from those near 55%. Finally, this study revealed that the exotic corn used in the study may be an important source of genes conditioning high amylose levels.