Abstract: The moisture content is very important for both forage and syrup use of sweet sorghum. In the present study， the gene Dd， which is related to moisture content of stem (MCS)， was proved as qualitative and the dominance of pithy over juicy type by the genetic analysis， using two F2 populations derived from a pithy cultivar Fangshannian crossing a juicy cultivar Shuangli and a juicy cultivar Btx623 crossing a pithy cultivar 7361. Primary mapping of the gene indicated that d was located on chromosome 6. By enlarging the mapping population， the locus was then fine mapped to a 470 kb interval between SSR markers sm06068 and sm06093 for F21 and sm06068 and sm06069 for F22. To narrow down the number of candidate genes， the target regions of Fangshannian， Shuangli and 7361 were sequenced and 2 InDel markers were mined. Finally， the locus was located to the region between markers sm06068 and Sb62， which harbored only six candidate genes. Genetic mapping of d provided an opportunity to identify genes involved in the moisture content of sorghum．

Key words: sorghum (Sorghum bicolor (L.) Moench), gene Dd, genetic analysis, fine mapping