Screening methods for cereal grains with different starch components: A mini review

The amylose content (AC) and amylopectin branch-chain distributions in grains determine the qualities and applications of cereal crops. Breeding crop cultivars with different starch components can meet the diverse demands of the food and nonfood industries for cereal grains. This paper reviews three methods for estimating ACs in grains and screening grains of interest from mutant pools and crossing segregated populations. The iodine colorimetry of starch can precisely determine the AC, but it is time-consuming to isolate starch from homozygous grains or halved grain. It is suitable for the identification of grains with different ACs from a small number of lines in high generation. Iodine colouration with a cut grain dip is not only the fastest, simplest, most economical and most efficient method to screen glutinous grains but can also reflect the changes in ACs. It is suitable for preliminary screening of grains of interest from the M-2 mutant pool and F-2 segregated population in the early generation. Iodine staining with urea-gelatinized grain can differentiate grains with very low and high ACs and extended branch-chain amylopectin and is especially suitable for screening grains with elite leaky alleles of starch synthesis-related genes from thousands of grains without visibly different phenotypes in the M-2 mutant pool.

Automated summary

The paper reviews three methods for estimating ACs in grains and screening grains of interest, providing insights into efficient identification and screening of grain quality.