After a several-year hiatus, University of Florida’s lettuce breeding program is up and running again at the Everglades Research and Education Center near Belle Glade.
Huangjun Lu, who joined the faculty as an assistant professor of plant breeding in June 2010, leads the effort.
He is joined by several other colleagues, such as Richard Raid, Gregg Neussley and David Sui, who provide input in their respective areas of expertise.
Lettuce is an important crop for the Everglades Agricultural Area, Lu says, with the South Florida region accounting for about 15 percent of U.S. production.
The crop—grown on about 11,000 acres—is valued at $30 million to $35 annually, with iceberg, romaine and baby lettuce being the main types.
Florida ranks third nationally, only to first-place California and second-place Arizona.
Much of Lu’s time initially has been spent taking inventory of existing university germplasm and conducting trials to determine what desirable traits the plant material might be able to contribute to his efforts.
The germplasm dates back to 1991, and many of the seeds were from the 1980s, he says.
Many of the envelopes and packages containing the seeds were broken, and Lu says only about 80 of the germplasms were still viable after all of these years.
In October 2010, he planted the seeds and found that some of the seeds didn’t even germinate while others produced plants that were stunted or never reached maturity.
He selected the best performers to use for crosses.
Developing a new variety that’s commercially viable takes at least 10 generations and about five years.
After each generation, breeders weed out all but the top 5 percent to 10 percent to move on. Lu says he makes about 50 crosses per year.
Lu also conducted trials in two locations to determine what desirable traits were present in commonly planted varieties.
Of the romaine varieties, he looked at Terapin, Manatee, Okeechobee and 70096, an unreleased UF variety. With crisphead, he looked at Gator, Raleigh and 8074.
Based on the trials, Lu says it appears that 70096 has resistance to banded cucumber beetle.
In addition, he’s developed a more efficient screening method for bacterial leaf spot, an unpredictable disease that can be devastating because there are no chemical controls.
The bacterial disease, spread by wind and rain, was serious in 2010 but almost non-existent in 2011.
Expanding the search
Lu obtained 178 other germplasm lines from the Agricultural Research Service’s lettuce germplasm collection in Pullman, Wash., to screen. One of those lines emerged from the screening without bacterial spot symptoms.