Fighting disease

All-America Selections celebrates its 80th anniversary this year, and as part of the celebration, Greenhouse Management will interview a different AAS judge each month to talk about how he or she runs his or her business and what AAS means to them. This is the second installment of the 12-part series.

When new vegetative material comes in to Todd Perkins at Syngenta, he can’t do what he wants with it quite yet.

Syngenta Flowers’ AAS trial gardens in Gilroy, Calif. Photo courtesy of Syngenta.

“Material comes in, and it’s in an isolated greenhouse, and it has restricted traffic,” says the flower breeder. “The understanding is it’s the last place you go in the day, and once you’ve been there, you can’t go anywhere else. There’s limited contact with the plant material.”

Unlike seeds, which are used for AAS trials and carry no disease risks, vegetative materials pose more of a threat to the greenhouse, so anything coming in undergoes several tiers of pathogen testing before it’s introduced into the greenhouse.

“You put them in, and you do the tests, and you get the results of the test, and if it’s positive, it’s destroyed,” Perkins says. “It’s real simple – it’s gone, and you sanitize the area. If it’s negative, you take cuttings, test it again, grow quasi-clean – we’re not sure they’re clean, but they just tested negative for the pathogens we tested for – so you grow them up again, take new cuttings, do tests.”

The initial testing takes only a few days, but the further testing could take much longer depending on how long it takes to regenerate a plant from a cutting. And the testing doesn’t come without its share of inaccuracies.

“As a human being, we get infected, and the infection may be localized,” he says. “You get a pathogen in your foot. If I’m testing your ear, I may not get the pathogen for months until it goes systemic. In plants it can be similar. They may get a viral infection transmitted by casual contact or an insect, and it might be localized for a while before it goes systemic. If you test the wrong part of the plant, you won’t know you have the virus.”

He says he also has to look for levels of the pathogen in the test.

“There’s a critical concentration of the virus you have to have to be able to sense it in a test, and if it’s too low, you may get a false negative – the negative saying I’m not responding to the virus being there, but it’s there,” he says. “It just hasn’t reached the concentration yet. You already have the infection but you can’t sense it.”

His quarantine has to account for that.

“So you do a general test and do a visual [inspection] for the symptoms,” Perkins says. “A lot of them are visually symptomless though. You don’t see it all, but they can be spreading it around.”

Once that happens, it can wreak havoc on the greenhouse.

“Once you get that into your system, it’s a terrific challenge to get it out,” he says. “It’s serious stuff. You have to take it very carefully.”

He’s been through that experience more than once, and it’s not something that’s worth the risk, so he’s incredibly vigilant in his testing and quarantining process to make sure he doesn’t infect the greenhouses. After a couple rounds of tests, he feels more comfortable moving forward with the material.

“If they come out negative twice and pass visual inspection – they appear clean, test clean for the known challenges we have – then we’ll introduce them into the general greenhouse area for breeding or evaluation,” he says.

But nothing skips this process, and he’s vigilant about fighting to keep diseases out of the greenhouses.

“It’s not worth it,” he says. “There’s nothing that we could bring in that would be worth the risk – nothing.”

For More: Syngenta Flowers, www.syngentaflowers.com/country/us/en/seeds/Pages/Home.aspx