Description:
The breeding lines were derived from a cross of 'King Louie' with 'Autumn Gold' using standard procedures for cross-pollinating lettuce in a greenhouse; the F2 was produced in the same greenhouse at Salinas. 'King Louie' is a Romaine type lettuce that was found to be highly resistant to Fusarium wilt in naturally-infected field tests in Yuma. 'Autumn Gold' is a Fusarium wilt-susceptible, iceberg type lettuce adapted to the early-Fall planting (September 1 to 20) time in Imperial Valley and Yuma. Fusarium wilt-resistant F2 segregants were selected in controlled inoculation greenhouse tests and saved to produce the F3 generation. The F3 families were evaluated in controlled inoculation greenhouse tests and their reactions confirmed in naturally-infected field tests in a commercial field in Yuma. Selected F4 families were evaluated for Fusarium wilt resistance in field tests in Yuma. Selected F5 families were field tested for disease reaction and plant type in Salinas Valley. The released germplasm is a group of F5 and F6 families resistant to Fusarium wilt and varying for plant type that is similar to iceberg; a few lines exhibit leaves with red coloration (anthocyanin).