Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unraveling the Genetics of Fusiform Rust

25.08.2003



USDA Forest Service researchers at the Southern Institute of Forest Genetics (SIFG) in Saucier, MS are mapping genes in the pathogen that causes fusiform rust to provide future forest managers with more insurance against the damaging disease.

Fusiform rust, a fungus that forms spindle-shaped galls on the branches and stems of pine trees, is endemic to the southern U.S., occurring from Maryland to Florida and west to Texas and southern Arkansas. Attacking several southern pine species, the fungus is most damaging to loblolly and slash pines. Both the frequency and severity of the disease have increased dramatically over the last 50 years.

"In old-growth natural forests, pine and fusiform rust co-evolved without severely limiting one another," said Tom Kubisiak, research geneticist at SIFG, a unit of the FS Southern Research Station. "In modern intensely managed plantations, planting limited numbers of the most highly productive families has actually contributed to an epidemic of fusiform rust."



Trees less than 10 years old suffer the highest rates of mortality from fusiform rust, but galls from the disease also weaken and deform older trees, causing stems to break during high winds. Economic losses from fusiform rust are estimated at $28 million a year.

Pathologists and geneticists have concentrated on identifying and breeding resistant families of trees by inoculating seedlings with bulk collections of fungal spores harvested from a broad geographical area. The resulting trees are resistant to fusiform rust in a general sense, but they are not immune to the disease. Seemingly resistant trees can be infected when exposed to pathogens with new or different genes for virulence.

Research at SIFG and other laboratories has shown that the interaction between pine and fusiform rust largely fits the classical gene-for-gene model. According to this model, disease is not simply a character of the pine host, but rather a result of the interaction between specific genes (resistance genes) in the host and specific genes (avirulence/virulence genes) in the pathogen. Simply put, each gene for resistance in the pine corresponds to a gene for virulence or avirulence in the fusiform rust pathogen.

’Trees with specific resistance genes can become infected by forms of the pathogen that carry virulence to these resistance genes. To more effectively manage for the disease, we need to not only identify and map the resistance genes in the host, but also identify and map the genes for virulence and avirulence in the pathogen," said Kubisiak. "So far, almost all of the research in this pathosystem has focused on the resistance genes in the pines, and very little work has been done to identify and map the genes that control virulence in the fungus."

Collaborator Henry Amerson (North Carolina State University) has identified as many as eight different genes for resistance in pine families. At SIFG, research geneticists Dana Nelson and Tom Kubisiak are using DNA markers to locate the corresponding genes for avirulence and virulence in the fusiform rust pathogen. To develop the populations of the fungus they need to map the genes, SIFG researchers are crossing difference fungal genotypes, a painstaking process that can take months.

"Our hope is to identify DNA markers tightly associated with each of the corresponding avirulence/virulence genes in the pathogen," said Kubisiak. "Then we can provide managers with an automated tool that directly estimates the frequency of these genes in natural populations of the fusiform rust pathogen. Managers can then use this information to determine which families of pines to plant in these areas."


--------------------------------------------------------------------------------

Researchers from the SRS Southern Institute of Forest Genetics (SIFG) are presenting findings from their work on fusiform rust disease at the Rustbusters 2003 symposium and at the 51st Western International Forest Disease Work Conference (WIFDWC), both held in Oregon the week of August 18th and sponsored by the USDA Forest Service.

Zoë Hoyle | SRS
Further information:
http://www.srs.fs.usda.gov/about/newsrelease/nr_2003-08-18-fusiform_rust.htm
http://www.fs.fed.us/r6/dorena/rustbusters/
http://www.fs.fed.us/foresthealth/technology/wif/index.php

More articles from Agricultural and Forestry Science:

nachricht Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy

nachricht New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>