IFAS News
Institute of Food and Agricultural Sciences – University of Florida
UF-led team sequences first-ever citrus genomes; discovery may help thwart greening
January 18, 2011
Topic(s): Citrus, New Technology, RECs
GAINESVILLE, Fla. — A University of Florida-led group of international scientists has assembled the genome sequences for two citrus varieties—sweet orange and Clementine mandarin—marking a first for citrus.
The Clementine mandarin sequence is the higher quality of the two, but both are expected to help scientists unravel the secrets behind citrus diseases such as greening, a deadly threat to the state’s $9 billion citrus industry, as well as aiding those working to improve fruit flavor and quality.
Florida citrus industry officials said they were thrilled, and relieved, by the news.
“The publication of the sweet orange and tangerine genomes will accelerate the discovery of innovative solutions to a myriad of pest and disease problems that threaten citrus production,” said Dan Gunter, chief operating officer of the Citrus Research and Development Foundation Inc.
Michael W. Sparks, executive vice president and CEO of Florida Citrus Mutual, a trade organization comprised of 8,000 members, called genomics “the future of not only Florida citrus, but the entire global citrus industry.”
“It is exciting to see breakthroughs such as the release of these (genome) assemblies and I am confident the talented scientists working on this project will eventually propagate a citrus cultivar that withstands disease pressure and allows consumers worldwide to continue enjoying nutritious citrus products,” he said.
The genome sequences, the result of at least four years’ worth of study and $3.5 million invested by several countries, were announced Saturday at the International Plant and Animal Genome Conference in San Diego.
The announcement comes just weeks after a similar announcement that another international team, led by UF Institute of Food and Agricultural Sciences and Virginia Tech scientists, had published the DNA sequence for the strawberry.
The Clementine mandarin genome came from a haploid, meaning it has a single set of chromosomes. The scientists used a more detailed method of obtaining its genome sequence, which was more expensive, but provides longer strings of DNA, said UF’s Fred Gmitter, a horticultural sciences professor and Institute of Food and Agricultural Sciences member who led the effort.
“For us, it means it gives you longer reads, longer pieces—so that you’re assembling a jigsaw puzzle out of a million pieces, instead of out of 25 million smaller pieces,” Gmitter said. “What’s most important is to have this high-quality, original haploid reference sequence. And we did that.”
The team that worked to obtain the gene sequence for the Clementine mandarin included scientists from the University of Florida, Italy, Brazil, France and Spain and the U.S. Department of Energy’s Joint Genome Institute (JGI). Simultaneously, work was being done to obtain the diploid sweet orange sequence by scientists from UF, JGI, Georgia Tech and 454 Life Sciences, a Roche Company.
“I’m proud that our scientists helped lead the way in this world-class research,” said Mark McLellan, IFAS’ dean for research. “We believe having these genome sequences will greatly help the state’s citrus industry, as well as citrus growers around the world.”
Since its discovery in Florida in 2005, greening has caused havoc in the citrus industry. It has wiped out some citrus crops in Asia, Africa, the Arabian Peninsula and Brazil. Greening slowly weakens and kills all types of citrus trees, while rendering fruit malformed and discolored.
But while the two new genome sequences may provide just the tool scientists need to help them solve the greening crisis, Gmitter said having them is “really much, much, bigger than that.”
Some of the possibilities, he said, include citrus trees with more beautiful fruit, better disease resistance, more phytonutrients, and tolerance for salt, bad soil or extreme temperatures.
California citrus grower Earl Rutz, vice chairman of that state’s Citrus Research Board, praised what he called “the first of its kind as a true international collaboration with benefits for all in the citrus research community.”
Peter McClure, a Florida citrus grower and former chairman of the Florida Citrus Research Production Advisory Council, called the genome sequences great news for the citrus industry, which has often battled serious foes in weather and disease.
“From a global perspective, unless sustainable solutions are found citrus will also become extinct for many subsistence level farmers around the globe that utilize citrus as an important fresh fruit nutrient source as well as an important high-value cash crop,” McClure said. “HLB (greening) is an extremely complicated disease problem, and sequencing the citrus genome is a real breakthrough towards solving HLB. There is still a lot of work to do, but this gets us closer.”
Ted Batkin, president of the California Citrus Research Board, praised the work, saying the new information could allow breeding of new varieties specific to geographic regions.
“The importance of a complete genome sequence cannot be stressed enough,” he said.
Contacts
Writer: Mickie Anderson, 352-273-3566, mickiea@ufl.edu
Sources: Fred Gmitter, 863-956-1151, ext. 1301, fgmitter@ufl.edu
Mark McLellan, 352-392-1784, mrm1@ufl.edu
UF agricultural honorary organizes national service project to feed Central Florida’s hungry
December 20, 2010
Topic(s): Agriculture, CALS, Citrus, IFAS
GAINESVILLE, Fla. — Gleaning, the age-old practice of collecting discarded crops from harvested fields, is getting new attention as a way for volunteers to supply soup kitchens and other charities with low-cost food.
This weekend, college students from across the country will converge on Orlando to glean citrus fruit from local groves. Then they’ll deliver, prepare and serve it in homeless shelters as part of a project organized by the University of Florida chapter of the agricultural honorary society Alpha Zeta.
It’s the first time UF’s chapter has hosted the organization’s annual holiday project, said Erika Schwarz, a UF animal sciences senior and coordinator of the event.
Alpha Zeta is the nation’s oldest honorary society for students majoring in agricultural disciplines. Founded in 1897, it has 70 chapters nationwide and promotes leadership, academic achievement and public service.
“We’ve gotten great response to the idea,” Schwarz said, noting that online registration filled up early, with 30 students signed on. “Gleaning is easy to organize and it has immediate results. It’s just a matter of getting the manpower and doing the manual labor.”
Coca-Cola and Cutrale announce $3 million in donations to boost citrus research
December 20, 2010
Topic(s): Agriculture, Citrus, Invasive Species, Pests
GAINESVILLE, Fla. — Coca-Cola and Cutrale Citrus Juices announced today at a meeting of the Florida Citrus Mutual in Lake Alfred that they have each pledged $1.5 million to the University of Florida for research programs.
The contributions will be used to fund sustainable research programs managed by the Citrus Research and Development Foundation, known as CRDF, a direct support organization of UF aimed at eliminating the threat of Citrus Huanglongbing, a disease commonly known as “greening.” HLB is one of the most destructive diseases of citrus crops, debilitating the productive capacity of citrus trees.
“In making this contribution, Coca-Cola and Cutrale will greatly enhance the ability of scientists at IFAS and around the world to find answers to this catastrophic problem,” said Jack Payne, senior vice president for agriculture and natural resources at the University of Florida.
Florida’s citrus industry could benefit from soil analysis concepts developing at UF
November 10, 2010
Topic(s): Agriculture, Citrus, New Technology
Cutline at bottom. Click here for high-resolution image.
GAINESVILLE, Fla. — Many of Florida’s natural conditions are perfect for growing citrus. One that’s imperfect is the state’s patchwork variety of soil types, and University of Florida researchers say the situation comes with a price tag for growers and consumers.
If the soil’s nutrient content or water-holding capacity differs from place to place, it can mean lower fruit yields, lower producer profits and higher consumer prices for fresh citrus and citrus juice, said Arnold Schumann, an associate professor with UF’s Institute of Food and Agricultural Sciences.
The findings appear in the current issue of the journal Soil Science.
Citrus groves are typically managed as if the soil were uniform. Consequently, areas with poorer-than-average soil may end up deprived of nutrients or irrigation, reducing the grove’s potential yield by 10 to 50 percent, he said.
“Almost every grove has some problems with soil variability,” said Schumann, at UF’s Citrus Research and Education Center in Lake Alfred.
UF researchers find lone culprit behind greening
December 9, 2009
Topic(s): Agriculture, Citrus, New Technology, RECs, Research
Click for full image. Caption at the bottom of the story.
GAINESVILLE, Fla. — University of Florida researchers have shown that the disease that threatens to devastate the world’s citrus crop is almost certainly the result of a lone species of bacteria, and not that of a combination of bacterial or viral pathogens as some have feared.
Using three types of next-generation genetic analysis, researchers from UF’s Institute of Food and Agricultural Sciences examined inner bark from Florida citrus trees infected with citrus greening.
While the team conclusively found the genetic fingerprint of the bacteria commonly suspected to be behind the disease, Candidatus Liberibacter asiaticus, the analysis showed no other DNA of suspect viral or bacterial pathogens.
The research, published in the December issue of the journal Molecular Plant-Microbe Interactions, is important because the disease has been especially difficult to analyze, said Eric Triplett, chairman of UF’s department of microbiology and cell sciences and lead researcher on the study.
Normally, researchers would prove that the bacteria is behind the disease by capturing a sample of the bacteria, growing it in a petri dish, and then inserting it into a healthy tree to see if it causes the disease.
However, scientists have not yet found a way to get the bacteria to grow in a petri dish. This means that scientists are having trouble using their normal approaches to researching the pathogen.
(more…)
UF releases first citrus cultivar; Sugar Belle packs a tasty punch
October 27, 2009
Topic(s): Agriculture, Citrus, Cultivars, Extension, Nutrition, RECs
GAINESVILLE, Fla. — Sugar Belle-a bold mandarin orange hybrid that ripens in time for the winter holiday market-will be the first University of Florida-created citrus variety intended for commercial production.
The mandarin hybrid-a mix of the sweet Clementine and the colorful, bell-shaped Minneola-has a rich taste and strong aroma, said UF Institute of Food and Agricultural Sciences plant breeder Fred Gmitter.
The new sweet-tart fruit may be best described as a mandarin with a tangy punch.
“Many old-timers in citrus have said this is the best-tasting citrus they’ve ever had,” Gmitter said.
The fruit, which has a patent pending and is also known as LB8-9, has been in the works since 1985.
New UF computer system could one day help citrus growers count fruit before harvest
June 21, 2007
Topic(s): Agriculture, Citrus, Crops, New Technology, RECs, Research
By:
Tom Nordlie (352) 392-0400Source:
Daniel Lee wslee@ufl.edu, 352-392-1864 ext. 227
GAINESVILLE, Fla. — Farmers are told not to count chickens before they hatch, but for citrus growers it’s a little different – knowing how much fruit is on their trees can help them make better decisions about managing and harvesting the crop.
So University of Florida experts are developing an electronic system to “see” and count fruit, a concept called machine vision. It could be commercially available by the end of the decade. (more…)
