A Rapid Single Kernel Screening Method for Preliminary Estimation of Amylose in Maize

The development of low glycaemic index maize varieties requires screening of a large number of inbreds in shortest time. Conventional amylose estimation methods are tedious, time consuming and involve high reagent costs. A simple and rapid screening method has been designed for amylose estimation in maize kernels, which is based on the principle of amylose-iodine complex formation. The method is named as cut grain dip method (CGD). The CGD method involved cutting of maize kernel longitudinally to expose the endosperm, followed by treatment with optimized potassium iodide:iodine (2:1) solution on the cut end and recording the time involved for maximum colouration. It was observed that time taken for iodine to reach its maximum colouration had an inverse relation to the amylose content (AC) in maize kernel. The method was validated in a large set of maize samples with varied amylose content and automation was also done with the use of AlphaView SA software. The proposed CGD method is a rapid and simple for screening of maize kernels with varied AC. The method does not rely upon costly reagents and gets completed in 1 min, therefore is suitable for large-scale screening of maize germplasm including mutants and wild types.