Registration of Four Diverse Random‐Mated Cotton Germplasm Populations

Dwarf GP (Reg. No. GP‐967; PI 669119), Fiber GP (Reg. No. GP‐968; PI 669120), Glandless GP (Reg. No. GP‐969; PI 669121), and Race GP (Reg. No. GP‐970; PI 669122) are four unique upland cotton ( Gossypium hirsutum L.) germplasm populations (GP) released by the USDA–ARS. Dwarf GP is a four‐parent, narrow‐based population developed to incorporate dwarfing genes into nondwarf genetic backgrounds. The remaining three populations are broad‐based, complex populations. Fiber GP (24 parents) was developed to include potential sources of variation that would improve fiber length and strength. At the time these populations were developed, a viable glandless seed industry existed, and Glandless GP (22 parents) incorporated glandless germplasm from public and private breeders. Race GP (42 parents) was developed to obtain new genetic recombination events among a set of primitive race stock parents. These populations were created to recombine the variability from multiple parents into a single source from which selection can be initiated. Glandless GP was formed by random mating for nine cycles using a bulked pollen methodology. Dwarf GP, Fiber GP, and Race GP were formed by random mating for one cycle using a bulked pollen methodology followed by eight cycles using a male sterile. These populations possess trait specific and non‐trait specific genetic diversity resulting from multiple generations of recombination and, therefore, present breeders with useful tools for improvement of elite germplasm.