Colinearity of putative flowering gene in both sugarcane and sorghum

Abstract

Sugarcane (Saccharum spp.) and sorghum (Sorghum spp.) have become increasingly important crops for biofuels production. Sugarcane has an autopolyploid complex genome, whereas sorghum has a diploid simple genome. Flowering is one of the sugar-related agronomic traits in both species. Here, we obtained cDNA of inflorescences at 0–15 cm from S. spontaneum using cDNA-amplified restriction fragment length polymorphisms to develop flower transcriptome profiling with 26 primer combinations. A total of 183 transcript-derived fragments (TDFs) were screened and 96 TDFs were sequenced. Out of 96 TDFs, 26 were selected as putative flowering genes to study collinearity with the sorghum genome. For gene collinearity, a genetic linkage map with 169 SSR co-dominant markers and 12 TDF marker loci were mapped to 14 linkage groups collectively spanning 1077.8 cM and corresponding to the 10 sorghum chromosomes. Interestingly, 9 TDF marker loci could be mapped to 5 linkage groups. In this study, we successfully identified the homologous location of sugarcane flowering TDFs in the sorghum genome and found that 4DS_1X and 2DS_3E TDFs may serve as candidate specific markers linked to flowering in both sorghum and sugarcane.