Novel allelic variations in Tannin1 and Tannin2 contribute to tannin absence in sorghum

Abstract

Abstract Sorghum is an important food crop commonly used for brewing, feed, and bioenergy. Certain genotypes of sorghum contain high concentration of condensed tannins in seeds, which are beneficial such as protecting grains from herbivore bird pests but also impair grain quality and digestibility. Previously, we identified Tannin1 and Tannin2, each with three recessive causal alleles, regulate tannin absence in sorghum. In this study, via characterizing 421 sorghum accessions, we further identified three novel recessive alleles from these two genes. The tan1-d allele contains a 12-bp deletion at position 659 and the tan1-eallele contains a 10-bp deletion at position 771 in Tannin1. The tan2-dallele contains a C-to-T transition, which results in a premature stop codon before the bHLH domain in Tannin2, was predominantly selected in China. We further developedKASP assays targeted these identified recessive alleles to efficiently genotype large population. These study provided new insights in sorghum domestication and convenient tool for breeding program.