2012 Annual Report 1a.Objectives (from AD-416): 1. To characterize selected germplasm lines of sorghum for response to cold stress at early season and at other specified stages of development and accelerate the development of improved germplasm resources for different types of sorghums. 2. To investigate the genetic and physiological basis of cold tolerance in sorghums through genetic studies of tannin genes in sorghum. 1b.Approach (from AD-416): 1. Establish replicated field trial of sorghum lines in various locations to estimate genotype by environment interaction. 2. Perform fine mapping of two QTLs in the population of 109 F6:7 RILS developed from Tx430/SQR, and in two additional mapping population Tx430/SC1103 and Tx430/SC1345, each with 250 F6:7 RILS and characterize, phenotypically and genotypically the 300-line sorghum diversity panel for testa layer. 3.Progress Report: For 2011-2012, progress in understanding the relationship between early season cold tolerance and tannins through QTL mapping and cloning of tannin genes in sorghum was achieved. A manuscript describing the cloning of the tan1 gene from sorghum was published. Further studies on the linkage of the tan1 gene with cold tolerance QTL from the Chinese cold-tolerant line Shanqui Red are being conducted. This progress report relates to partial completion of objective 4 of the parent project.