Posts Tagged: greening disease
Deadly Citrus Greening Disease: A Better Lure for Asian Citrus Psyllids
If you like or grow citrus, you ought to be worried about the worldwide threat of the deadly citrus...
UC Davis chemical ecologist Walter Leal (center) examines a lure in Mogi Mirin, São Paulo on Brazil’s Independence Day (Sept. 7) with Haroldo Volpe (far right) and Renato de Freitas, both of Fundecitrus.
Culturing CLas to improve HLB management
Candidatus liberibacter asiaticus (CLas), the bacterium thought to cause huanglongbing (HLB),...
Targeting the Asian Citrus Psyllid
A major citrus pest may experience a “Bah, Humbug!” kind of year. If all goes as...
The Asian Citrus Psyllid Team: Scientists in the front row (from left) are Tatiana Mulinari, Rodrigo Magnani, Antonio Juliano Ayres, Walter Leal, Marcelo Miranda, Victoria Esperanca, Odimar Zanardi, and Rejane Luvizotto. The three scientists in back are Haroldo X. L. Volpe (white shirt) Renato de Freitas and Rômulo Carvalho.
Resistant Citrus Selections to HLB?
Three citrus trees that produce inedible fruit at the UC Lindcove Research and Extension Center in Visalia may be a game-changer for the citrus industry, reported Ezra David Romero on Valley Public Radio.
The trees are thought to be resistant to huanglongbing, a severe disease of citrus that has devastated the Florida industry and could become a serious problem in California. The citrus-saving potential of the three 34-year-old trees was outlined in an article by UC Agriculture and Natural Resources writer Hazel White in the most recent issue of California Agriculture journal.
UC Riverside citrus breeder Mikeal Roose collected seed from the trees and will test seedlings as soon as they are large enough.
"So what (breeders) have to do is cross this with some edible varieties and eventually create something that has the gene for resistance, but also the genes for good fruit," said Beth Grafton-Cardwell, Lindcove director and research entomologist.
Huanglongbing disease has cut citrus production in Florida by more than half. It's been found in residential citrus trees in Southern California, but hasn't reached the state's vast commercial orchards yet. Grafton-Cardwell said she expects the disease will arrive in 4 or 5 years.
Yeah!!!!
HLB resistant variety
Some Genetic Resistance/Tolerance to HLB
Ed Stover and crew at USDA, Fort Pierce in Florida have been studying the response of different scions and rootstocks that have been inoculated with the HLB bacteria. As reported in the Proceedings of the International Citrus Conference (http://www.icc2016.com/images/icc2016/downloads/Abstract_Book_ICC_2016.pdf), they have found some scion/rootstock combinations more tolerant or less susceptible to the disease six years after they have been inoculated. It turns out scions with a citron pedigree have more resistance. Also those with a Poncirus (trifoliate) background also had lower populations of the bacterium.
What this means is that there is resistance and possible immunity out there and there is breeding/genetic engineering material out there that can be used to improve the whole of the citrus family to HLB. Of course, this will take time, but there is hope.
Photos:
HLB symptoms and trifoliate leaves
HLB symptoms
trifoliate