Location: Crop Improvement and Protection Research
Project Number: 2038-21530-003-010-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Apr 1, 2022
End Date: Mar 31, 2025
Develop landmark cultivars, advanced breeding lines, information, and tools for use by other breeders, scientists, producers and growers. Problems facing the lettuce industry will be addressed using genetic approaches that are suited to coastal, desert, and interior valley locations, to the various types of lettuce, and to the demands of different production and marketing approaches.
The lettuce industry of California requires continued development of improved, adapted cultivars to meet new disease and insect problems, changes in the market, and changes in growing procedures. In most situations, improved cultivars are the least expensive option for developing sustainable production systems. We organize our breeding priorities towards specific traits of lettuce where the need for genetic improvement is evident, and success is feasible. For example, disease and insect resistant cultivars are being developed in cases where no feasible cultural control options exist, or the current options offer insufficient control (e.g., Verticillium wilt, Fusarium wilt, bacterial leaf spot, lettuce drop, dieback, corky root, Tospoviruses). In other cases, resistant cultivars also reduce production costs associated with pesticide use (downy mildew, leafminer, and lettuce aphid). We are also developing cultivars with resistance to specific defects needed to maintain a continuous supply of marketable lettuce (bolting resistance, tipburn resistance), increase the efficiency of the fresh-cut lettuce industry (extended shelf-life), and to enhance the marketability of the crop (novel spring mix types). The USDA breeding and genetics program has ongoing research into 14 characteristics encompassing disease resistance, insect resistance, resistance to physiological defects, enhanced shelf-life of fresh-cut lettuce, and development of novel leaf forms for use in spring-mix.