Breeding for Pierce’s Disease Resistance Has Sped Up

Traditional Breeding Helps Find Resistance to PD

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter is a major vector of Pierce’s Disease, which kills grape vines. Pierce’s Disease devastated the grape industry in southern California and lead to the creation of the Pierce’s Disease/Glassy-Winged Sharpshooter Board (PD/GWSS Board). Government programs to fund research on glassy-winged sharpshooters and Pierce’s Disease invest nearly $20 million annually.

California Ag Today recently spoke with Ken Freeze, the outreach and education director for PD/GWSS. He told us about two major methods of control and prevention that the board is funding.

“There’s the area-wide control program, which does everything it possibly can to pretty much keep the glassy-winged sharpshooter confined to basically the southern part of the state,” Freeze said.

This control program prevents the further spread of Pierce’s Disease into other parts of the state, which could devastate wine growers. In addition to preventing the further spread of Pierce’s Disease, the board is also funding additional research into hopefully finding a cure.

“We’ve got UC Davis Genetics Professor Andy Walker working on Pierce’s Disease resistant grapevine before the program, and he just released some of those vines to the UC Davis Foundation Plants Services.”

Freeze said this development has been done through traditional breeding, with the assistance of some new technology.

Walker’s traditional breeding is sped up by a lot of high tech tools. Previously growers would crossbreed, however they’d have to infect the vine and see if it got Pierce’s Disease.

“That could take a year or two. Now they know the genetic markers, so when the plant has only two or three leaves on it, researchers pull a leaf, do a DNA track on it, and look for that marker,” Freeze explained.  “Depending on the marker, the vine either goes to the next step in breeding or it ends up in the trash heap. So that has just sped up that process incredibly.”

“Again, that’s all just using traditional breeding,” Freeze said.

More California Ag News

Pierce’s Disease Research Advancing Many Projects Under Way To Reduce Pierce’s Disease in Grapes By Patrick Cavanaugh, Farm News Director The glassy-winged sharpshooter vectors Pierce'...
Huanglongbing Top Importance in Citrus Huanglongbing Disease in Citrus is Top Problem By Patrick Cavanaugh Farm News Director Gary Schulz, President of the Citrus Research Board in Visali...
BPIA Executive Director Talks Biological Products Biological Product Industry Meets in Orlando By Patrick Cavanaugh, Farm News Director Nearly 200 individuals from the worldwide biological products ...
BioSafe Systems Offers Biological Control Products BioCeres Beneficial Fungi Kills Important Pests By Patrick Cavanaugh, Farm News Director California Ag Today recently interviewed Jay Sughroue, Ph.D...

Pierce’s Disease Research Advancing

Many Projects Under Way To Reduce Pierce’s Disease in Grapes

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter vectors Pierce’s Disease, which has been devastating grape growers in California for the last few years. California Ag Today recently spoke with Ken Freeze, the Outreach and Education Director for the Pierce’s Disease/Glassy-Winged Sharpshooter Board, a program that uses winegrower’s assessments to fund research. He spoke with us about research that’s been carried out to hopefully find a cure for Pierce’s Disease.

Pierce’s Disease is caused by a bacterium, Xylella fastidiosa, that reduces the vascular function of the vine. The sharpshooter insect vectors the bacteria.

“Andy Walker, with the Department of Viticulture and Enology, UC Davis, has been working on Pierce’s Disease-resistant grapevines. We just released some of those vines to the Foundation Plant Services at UC Davis,” Freeze said. “There are 14 more that are in the wings about ready to go. Some nurseries will be able to get that pretty soon, but already there are about 4,000 of his vines planted. Some of them have been planted in Georgia and Texas, which are real hotspot for the glassy-winged sharpshooter and Pierce’s Disease.”

“Here in California, 2,000 vines were planted in Napa Valley right along the Napa River. Those vines are doing great,” Freeze said.

“We’ve got another project. University of Florida plant pathologist Dr. Don Hopkins has found a benign stain of Pierce’s Disease. It’s like inoculating a vine with a smallpox vaccination. That’s actually a company that’s working on commercializing that now,” Freeze explained.

“We’ve got another project that involves a modified root stalk that sends either a protein or a molecule up into the vine – a non-modified scion – five different ways that stops the Xylella fastidiosa bacteria literally in its tracks before it can cause Pierce’s Disease in the vine. That’s just a small sample of some of the really good projects.”

“One grower told me: ‘It’s not the end of the tunnel, but we can see it,’” Freeze said.

More California Ag News

Raisin or Wine Grape Decision is Made Early Going Raisins or Going Green for Wine By Brianne Boyett, Associate Editor California Ag Today recently spoke with Jeff Bitter, vice president of All...
BPIA Executive Director Talks Biological Products Biological Product Industry Meets in Orlando By Patrick Cavanaugh, Farm News Director Nearly 200 individuals from the worldwide biological products ...
Huanglongbing Top Importance in Citrus Huanglongbing Disease in Citrus is Top Problem By Patrick Cavanaugh Farm News Director Gary Schulz, President of the Citrus Research Board in Visali...
BioSafe Systems Offers Biological Control Products BioCeres Beneficial Fungi Kills Important Pests By Patrick Cavanaugh, Farm News Director California Ag Today recently interviewed Jay Sughroue, Ph.D...

Modifying Rootstocks to Fight, Prevent Pierce’s Disease

Scientists Help Grapevines Double-team Pierce’s Disease

By Patrick Cavanaugh, Farm News Director

 

The glassy-winged sharpshooter is a flying insect that vectors a fatal grapevine malady known as Pierce’s Disease. Scientists are conducting volumes of research to fight this insect and reduce disease infection on vines. Moreover, scientists are studying methods to prevent the spread of Pierce’s Disease on winegrapes in California entirely.

California grapevine rootstock
California grapevine

Ken Freeze is the outreach coordinator for the California Department of Food and Agriculture (CDFA) Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS) as well as an account director at Brown-Miller Communications. On behalf of the PD/GWSS Board, Freeze communicates with winegrape growers who pay the Board an assessment to conduct research. Freeze explained ongoing research and how research funds are being spent.

FIGHTING PIERCE’S DISEASE

Could introducing pectin into grapevines, help prevent that bacteria, Xylella fastidiosa, from entering the vine? Freeze said, in a recent field trial, “scientists found five different genes that when placed in a rootstock, put either a molecule or a protein up into an unmodified scion that in one way basically stops the bacteria from moving around,” he said.

“For instance, one of the genes comes from the pear,” said Freeze. “I think we’re all familiar with pectin. A lot of plants produce pectin naturally; grapevines are not one of them. By modifying a rootstock with this pear gene, when the bug comes and injects the bacteria into the plant, the pectin literally gums it up and it can’t move around.”

An unmodified plant injected with bacteria by the glassy-winged sharpshooter, turns to another strategy. “When the bacteria population reaches a certain point, [the plant] releases a protein that causes the bad bacteria to stop moving around. However, in grapevines, it is too late when that signal comes; the plant is already dead. By modifying the rootstock to automatically generate that same protein when the bacteria enters the plant, the bacteria shuts down,” said Freeze.

winegrapes fight Pierce's Disease
Winegrapes

Freeze said scientists are seeing that these strategies are working quite well. “What scientists are actually doing now is stacking these genes, two by two, in the rootstock. Now each root will produce two different ways to shut down the bacteria. If for some reason in the future the bacteria figures out a way to overcome one of those ways, chances are it won’t figure out how to overcome both of them.”

PREVENTING PIERCE’S DISEASE

Dr. Andy Walker, a UC Davis professor and geneticist in the Department of Viticulture and Enology, has been working for years on rootstock that could block Pierce’s Disease from entering the vine. “He’s already released 14 different varieties to the Foundation Plant Services as well as three different rootstock that are resistant to Pierce’s Disease,” said Freeze. “The best varieties will be released to nurseries probably next year. Then from there [nurseries will] basically start growing them and taking orders from winegrowers.”

Freeze noted that other field trials are continuing. “We have field trials for a benign strain of Pierce’s Disease. It is like giving plants a smallpox vaccination, only it is the bacteria. That is on its way to commercialization. In the future, you might actually order your new vines from the nursery pre-infected with the bacteria that would normally cause [Pierce’s Disease]. But in this case, it will not cause it,” said Freeze.


CDFA Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS)

CDFA Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS) Interactive Forum

CDFA Pierce’s Disease Control Program

UC Davis Department of Viticulture and Enology

UC Davis Foundation Plant Services

More California Ag News

New Website Launched to Promote Yes Vote on Pierce... Pierce's Disease Website to Help Inform Winegrape Grower/Vintner Community Winegrape growers and vintners anxious to better understand why their “yes...
UC ANR Horticulture Advisor Retires After 28 Years John Kabashima wrapped up his horticultural career on July 1, after 28 years with University of California Agriculture and Natural Resources. Nursery ...
CDFA Announces Dates for PD/GWSS Winegrape Grower ... The California Department of Food and Agriculture (CDFA) has announced important dates for this year’s vote on the continuation of the statewide Pierc...
THE COST OF PIERCE’S DISEASE and GWSS Grapevine Diseases Costs Wine Grape Growers and State Issues relating to various grapevine diseases, including Pierce’s Disease (PD), grapevine lea...