The use of molecular markers is one of the most sensitive, powerful technologies for genetic purity assessment of seed lots. In this study, we aimed to develop a set of insertion and deletion (InDel) markers, through bioinformatics approaches, that may effectively distinguish three representative japonica rice (Oryza sativa L.) varieties, Nipponbare, Taichung 65 and Zhonghua11. The published whole-genome sequences of these varieties were aligned using BWA-MEM, followed by manual inspection for InDels of more than ten base pairs in size with the tview function of SAMtools. A set of ten InDel markers were thus identified and then validated by PCR in the three japonica rice varieties and their intercross F1 hybrids. Results showed that the InDel markers developed in this study could reliably distinguish these three japonica rice varieties. These molecular markers together with the detection method developed here can be applied to DNA-based genetic purity evaluation in rice breeding.
