The UF/IFAS lettuce breeding program research's main topic is investigate on Biotic and Abiotic Stresses, disorders and other values for the lettuce industry
Biotic Stresses
Bacterial Leaf Spot of Lettuce is caused by Xanthomonas hortorum pv. vitians and is the most concerning disease to growers in Florida and everywhere else where the crop is planted. Curative measurements is not possible neither prophylactic control due to the sporadic appearance of this disease. Producers rely on host resistance to control this disease. The UF/IFAS Lettuce Breeding team is improving lettuce against this disease.
Although, Fusarium Wilt of Lettuce is not a threat to the Florida industry, the disease was seen and confirmed the state in 2017. UF/IFAS lettuce researchers are working to stop this possible threat that could diminish lettuce yield in Florida. The disease is caused by the fungus Fusarium oxysporum f.sp. lactucae with four races identified worldwide but only one present in the United States including Florida, race 1. Due to the limited amount of controls for this fungus, host resistance is the most sustainable control method; resistant cultivars are being improved in adapted Florida lettuce.
The most important disease in lettuce is Lettuce Downy Mildew, which is caused by the oomycete Bremia lactucae. This oomycete has developed many races worldwide and will continue to cause damage to growers. We are working to identify the races of this oomycete in Florida to design better Integrated Disease Management Practices, including host resistance.
Abiotic Stresses
In warmer environments as the one is South Florida, heat tolerance is much needed; warm temperatures diminish yield in lettuce and other leafy vegetables. Particularly in lettuce, warm temperatures decrease seed germination if seed is not thermotolerant. Additionally, lettuce bolts prematurely, may show tipburn and/or not reach the proper market size. We are identifying tolerance to both, germination and adult plants to incorporate both tolerances in the elite lines of the UF/IFAS lettuce breeding program.
Other issues
Due to the limited durability of the phosphate rock, cultivars for future production systems must phosphorus efficient. Efficient lettuce cultivars to fertilizers could save growers on production costs and have less environmental impacts. The UF/IFAS lettuce breeding program seeks to improve lettuce cultivars capable of efficiently uptake P from soils.