Characterizing and Breeding Drought Tolerance in Lettuce - UNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSION

Goals / Objectives
Supplies of irrigation water for leafy vegetable production in California are increasingly constrained due to both climate change and regulatory restrictions. Reduced water availability is a statewide problem affecting all major lettuce producing regions. A predicted rise in temperatures will lead to increased evapotranspiration that will increase the water requirement of lettuce. Thus, there is a pressing need to adapt lettuce production to the changing environment in order to protect and even increase current production levels. The purposes of this project are to identify traits underlying drought-tolerance in lettuce at both the physiological and molecular levels and incorporate these traits into new cultivars protecting yields. This project aims to contribute to water conservation, reducing production costs, and increasing the profitability of the lettuce industry while simultaneously increasing the sustainability and protecting the future of lettuce production in California.

Project Methods
In the first year, drought-tolerance traits in lettuce at the physiological level will be identified utilizing both greenhouse and growth chamber water-stress experiments. In the first year the expression patterns of known drought-responsive genes will also be analyzed using quantitative real-time polymerase chain reaction while simultaneously utilizing the lettuce genome to identify novel drought-responsive genes. Breeding to incorporate drought-tolerance traits will begin immediately upon the identification of such traits and will become the primary component in the second year of this project focusing on the development of breeding lines. Drought-tolerant breeding lines/cultivars developed will be grown under water-stress conditions in the Salinas Valley in the third year to demonstrate results to producers and seed companies, which can incorporate these drought-tolerant traits containing lines into existing breeding programs to produce cultivars for commercial production by growers.