Narrative
Developed during Brummer SAC project [ See https://portal.nifa.usda.gov/web/crisprojectpages/1027227-development-and-characterization-of-diverse-hemp-germplasm-for-submission-to-the-npgs.html ]. Hemp (Cannabis sativa L.) has been cultivated on the North American continent since the 17th century for ropes, sails, and clothing. Its cultivation waned due to competition from cotton and, later, the appearance of synthetic fibers. In the 20th century, it was first restricted (1937 Marihuana Tax Act), then encouraged during World War II (“Hemp for Victory”), and later prohibited under the 1970 Controlled Substances Act, with various efforts to eradicate it from the landscape—achieving mixed success. Currently, feral hemp populations remain across multiple states. These surviving and locally adapted populations could be of crucial importance to the future of the national hemp industry. They preserve genetic diversity adapted to cold climates, short seasons, and low-fertility soils in marginal conditions, with presumably good resilience against pests and diseases. This historic germplasm holds pre-breeding potential for all types of Cannabis production. In recent years, relaxation of regulations and growing interest in hemp have prompted the need to preserve these resources at the USDA NPGS, and hundreds of collected wild seeds have entered germplasm collections. These small seed lots are of varying quality and seed increases must be done to produce seeds available for distribution to NPGS customers. However, because hemp is wind-pollinated and day-length-sensitive, and usually dioecious, seed increases must be done under isolation, which is difficult due to their abundant production of pollen and the small size of pollen making exclusion difficult. As an alternative to distributing many individual accessions, in this project, we aimed to create a large random mating population derived from 92 representative feral synthetic accessions from Illinois, Iowa, Nebraska, North Dakota, Wisconsin, and New York. An approximately equal number of seedlings (males and females) from each entry were intercrossed for three generations. In each cycle, we collected seeds from every female plant and monitored maternal lineages. In the final round, we grow the plants to generate a larger volume of seeds, which we mixed in a balanced fashion to maintain diversity. The resulting seed lot was submitted to the USDA NPGS and is accessible to breeders and scientists as UC Feral Synth One (G 33949). In the 2025 season, we are evaluating this population in three different states—Geneva, NY; Madison, WI; and Davis, CA—to assess diversity, general agronomic performance, and potential disease and insect resistances.