Molecular marker assisted screening for kernel polyphenol oxidase activity in wheat Triticum aestivum L.

Abstract

High level of kernel polyphenol oxidase (PPO) activity has been found to be the major factor behind time-dependent discolouration of wheat-based products, which ultimately leads to reduced consumers’ preference. Till date, 6 genes belonging in 2 paralogous sets present in wheat (Triticum aestivum L.) chromosome 2 homeologues (2A, 2B and 2D) have been reported to govern kernel PPO activity. Among these 6 genes, perfect molecular markers have been developed for 2 genes (PPOA1 and PPOD1) and the major role of PPOA1 gene in governing kernel PPO activity in wheat has been reported. In the present study we have used the molecular markers for the PPOA1 and PPOD1 genes to characterize wheat genotypes for their kernel PPO activity. We have successfully converted the dominant marker assay for the PPOD1 locus into a co-dominant assay using the already reported primers. Our molecular screening strategy could explain the kernel PPO activity of wheat genotypes in rapid, reliable and environment-independent manner. Furthermore, biochemical estimation of kernel PPO activity in wheat genotypes indicated the involvement of other genes in fine-tuning this important trait. Thus, the present study should facilitate the breeders in marker-assisted selection and breeding for developing wheat genotypes with low kernel PPO activity.