Title: Aims Library - a Community Resource for Sorghum Genomic Studies and Breeding Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2009
Publication Date: August 12, 2009
Citation: Xin, Z., Burow, G.B., Burke, J.J. 2009. AIMS Library - A community resource for sorghum genomic studies and breeding[abstract]. Sorghum Improvement Conference, August 11-12, 2009, Amarillo, Texas. Technical Abstract: The sorghum genome sequence is completed. A systematically mutagenized population linking gene function to sequence is becoming increasingly urgent. A project was initiated to develop an Annotated Individually-pedigreed Mutagenized Sorghum (AIMS) library using (EMS) ethyl methane sulfonate for selection of agronomic trait mutants, as well as for isolating mutant series of sequenced genes to study the function of these genes using reverse genetic techniques, such as TILLING (Targeted Induced Local Lesion IN Genome). We have developed 3,200 pedigreed mutant lines. A subset of 768 mutant lines was analyzed by TILLING using four target genes. A total of five mutations were identified resulting in a calculated mutation density of 1/526 kb. Two of the mutations identified by TILLING were verified by sequencing in the gene encoding caffeic acid O-methyltransferase (COMT) in two independent mutant lines. Two mutant COMT lines segregate for the expected brown midrib (bmr) phenotype, a trait associated with reduced lignin content and increased digestibility. Many altered important agronomic traits, such as panicle morphology, panicle size, number of tillers, height, flowering time, and senescence were observed. The diversity of the mutant phenotypes observed in the field and the density of induced mutations calculated from TILLING, indicate that this mutant population represents a useful resource for sorghum genomic studies and may also serve as a resource for breeding to improve sorghum for special uses.