SRAP Molecular Marker of Sugar Content and Juice Yield in Sweet Sorghum

Abstract

As an important energy crop, sweet sorghum ( Sorghum bicolor L. Beauv) has been recognized around the globe. The present work utilized recombined inbred F 2:3 population derived from the hybridization of 141 sweet sorghum “W455” and grain sorghum “Xinliang 52” as starting material to locate the molecular markers associated with sugar content by using BSA method combined with SRAP molecular markers. The results showed that the sugar content belonged to a single gene with additive-dominant effects or single gene with additive effect and the juice yield was controlled by poly-genes. A SRAP marker (M3E7-S248) linked to the sugar content gene was found to be located on chromosome 7. From the comparison of nucleotide sequences, we found that it had 79% similarity with sorghum adenosine diphosphate glucose pyrophosphorylase subunit SH2. Three SRAP markers M8E2-J727 (M8E2-J712), M8R12-J241 and F13E9-J150 linked to juice yield gene were found located on chromosome 6. However, other two SRAP markers namely M8E2-J712 and M8E2-J727 were found co-dominant. The nucleotide sequencing results showed that the marker M8E2-J712 was highly consistent with the oxygen capture enhancement protein in chloroplasts of many plants. The marker M8E2-J727 was 99% consistent with a sequence of mRNA of sorghum bicolor unknown functional protein. The markers M8R12-J241 and F13E9-J150 were both highly consistent with the unknown gene sequences on chromosome 6.