Efficient measurement of amylose content in cereal grains

Rapid and economical measurement of amylose content in barley is important for genetic study and breeding improvement of this trait. Seventeen genotypes with a wide range of amylose contents were used to compare the amylose measurement accuracy of the cost-effective iodine–potassium iodide (I:KI) method to the commercially available enzyme-based Megazyme protocol. Comparable accuracy from I:KI was demonstrated in low amylose samples (below 10% dried base), as were limitations in regular or high amylose samples. To address the major cost of sample preparation in nutritional trait analysis, the I:KI method was also employed for amylose detection from β-glucan and free phosphate assay samples. Results indicated that samples used in β-glucan and phosphate assays could be further utilized for amylose measurement. Amylose detection accuracy using I:KI method from those assayed samples is comparable to that using the Megazyme method in low and regular amylose samples. Development of protocols for the double assays from one grain sample will significantly reduce the labor cost associated with sample preparation and will streamline the screening of early generation barley populations, where seed sample amounts are limited.