Abstract:Sorghum plays an important role in white wine industry and agriculture supply-side reform. Grain tannin and color are two important agronomic traits, but molecular genetic mechanisms of these two traits were not clear, and there were no cloned genes refered to grain color in sorghum to now. 325 recombinant inbred lines were constructed with BTx623 (white grian and low tannin) and Rio (pink grain and high tannin). Combination of two years phenotype data, 118 simple sequence repeat (SSRs) and 8 insertion-deletion (INDELs) markers, and QTL IciMapping4.1 were used in mapping with inclusive composite interval mapping (ICIM) method. 3 and 6 QTLs were mapped, which related to content of grain tannin and seed color, respectively. QTL qTan4-1 was controlled by a known gene Sb04g031730, and the other two QTLs, qTan1-1 (txp11 - txp279, 1.29%) and qTan2-1 (txp298 ~ SB1292, 1.28%) were new in content of grain tannin QTL analysis. In grain color analysis, qGC1-1 (1.00% and 12.03%), qGC1-2 (2.64% and 16.96%), qGC1-3 (22.81%), qGC2-1 (1.00%), qGC2-2 (1.19%) and qGC6-1 (15.08%) were mapped between txp11 - txp279, txp43 - txp11, 1d1A3- sam44127, txp72-txp298 and txp298-SB1292, txp57- sam43683 (chr6), repectively. Our study paves a way to fine mapping grain tannins and color, gene cloning and marker-assisted selection breeding.

Abstract:Identification and evaluation of 532 sorghum accessions newly stored in the National Genebank during 2001-2003 have been carried out with respect to four quality traits of protein,starch,lysine and tannin content. Furthermore, the correlations between quality traits of sorghum accessions were calculated. The results showed that characters of four quality traits appeared to be normal distribution, respectively. The different variations of the traits of sorghum accessions were revealed, therein, tannin content varied most. And among the four traits existed different relationships. Comparing with each quality trait of sorghum accessions of different origins, it could be found that lysine and tannin quality characters of bred sorghum were superior to that of landraces. Therefore, several high grade sorghum accessions possessing one or two even more good quality traits had been singled out through screening.