Registration of the BTx623/IS3620C Recombinant Inbred Mapping Population of Sorghum

The BTx623/IS3620C sorghum [Sorghum bicolor (L.) Moench.] mapping population (Reg. No. MP-1, NSL 469802 MAP) is a set of 430 F-7 and F-9 recombinant inbred lines (RILs) (F-7 lines: PI 658758 through PI 659060; F-9 lines: PI 659144 through PI 659271) from a cross between the inbred lines BTx623 (PI 659985 MAP) and IS3620C (PI 659986 MAP). This sorghum mapping population was released jointly by the Plant Stress and the Germplasm Development Unit, Cropping Systems Research Laboratory, USDA-ARS, Lubbock, TX and the Crop Germplasm Research Unit, USDA-ARS, College Station, TX in 2009. The original 137 RILs of this mapping population served as the basis for the construction of landmark high-density genetic and physical maps, with the integrated genome map subsequently used to aid in assembly of the sorghum genome sequence. This population has been genotyped by a number of investigators with a total of 3348 markers-including amplified fragment length polymorphisms, DArT (Diversity Arrays Technology, Yarralumla, Australia), restriction fragment length polymorphisms, simple sequence repeats, and insertion-deletions-mapped to ten linkage groups corresponding to the ten sorghum chromosomes. The population has been utilized to map quantitative trait loci that underlie various agronomic traits, including tillering, floral architecture, plant height, flowering date, grain size, and abiotic stress tolerance. The registration of this recombinant inbred mapping population will allow public access to the genomic and germplasm resources that can facilitate mapping and gene discovery for complex traits in sorghum and related cereal species.