New research tackles devastating peanut root rot

Author: | Date: 04 Nov 2014

Image of GRDC-funded PhD student Kylie Wenham inspecting a peanut plant in the glasshouses at the J.Bjelke-Peterson Research Station at Kingaroy.

Key Points

  • Neocosmospora vasinfecta is a major soil borne fungal root rot pathogen found in all peanut growing areas of Australia that has caused yield losses of up to 90%.
  • There is a lack of information available globally regarding Neocosmospora infection in peanuts but this is being addressed through new research work being undertaken by GRDC-funded PhD student Kylie Wenham.
  • The project is assessing the pathogen’s form and structural characteristics, the growth and development of the fungus both in vitro and in situ, the optimal growth conditions favoured by the fungus as well as the optimal environment for the fungus to proliferate and infect crops.

Neocosmospora vasinfecta may be an unfamiliar name to many Australian peanut growers but the devastating damage it inflicts on crop yield certainly isn’t.

It is a major soil borne fungal root rot pathogen found in all peanut growing areas of Australia that has caused yield losses of up to 90% but to date the industry has little understanding of the disease’s biology or characteristics and there are no control options currently available.

That is set to change though thanks to new research work being undertaken by Grains Research and Development Corporation (GRDC) funded PhD student Kylie Wenham who is studying the soil borne pathogen through the University of Queensland’s (UQ) School of Agriculture and Food Sciences.

Based at the J.Bjelke-Peterson Research Station at Kingaroy, Ms Wenham is focussing on the biology and ecology of Neocosmospora vasinfecta (N. vasinfecta) and aims to develop rapid phenotypic screening techniques for resistant genotypes in the Australian peanut breeding program.

Neocosmospora Root Rot was first identified in 2005 as the causal pathogen of a severe root and crown rot affecting a peanut crop at Ban Ban Springs in the North Burnett which caused yield losses of up to 40%,” Ms Wenham said.

“In the 2008/2009 season, there was another major crop loss of 50% reported in the Emerald region.

“Since 2005, the disease has since been identified in all peanut growing regions and all commercial peanut cultivars are susceptible to the disease.

“While there is detailed literature on the ecology and biology of other soil borne diseases of peanuts there is a distinct lack of information available globally concerning Neocosmospora infection in peanuts and that’s what we aim to address.

“This work is initially addressing a series of questions around the disease cycle and our studies will help determine the primary source of inoculum, how the pathogen becomes dispersed in the field, how infection takes hold in plants and whether injury, nutritional deficiency or abiotic stress have an influence, as well as how the pathogen survives in the soil, how long it survives in soil and whether it can survive for prolonged periods in stubble residues.”

With the disease estimated to have cost industry up to $5.4 million in 2011/12 alone, the research work promises to have wide ranging implications for growers including improved management options and eventually the development of new peanut cultivars that are genetically resistant to root rot.

“The outcomes of this research project will allow for the development and assessment of new management options including cultural control methods, chemical control methods, disease management planning and risk assessment for peanut growing areas,” Ms Wenham said.

The project is assessing the form and structural characteristics of N. vasinfecta, the growth and development of the fungus both in vitro and in situ, the optimal growth conditions favoured by the fungus as well as the optimal environment for the fungus to proliferate and infect crops.

Genetic sequencing is being undertaken to determine whether there is any genetic variability between N. vasinfecta isolates collected from different regions and hosts.   The isolates collected were sampled from infected plant material exhibiting symptoms consistent with those reported for the disease. (Isolates are fungal colonies on agar/media plates).

It will also determine the disease-producing capacity of different isolates of the fungus and will assist with isolate versus cultivar selection for phenotypic screening.

“The development of rapid screening techniques for this soil borne disease under controlled conditions offers plant breeders the opportunity to achieve early generation selection and hence save precious time and resources,” Ms Wenham said.

“There is also potential to develop molecular markers for these traits via collaboration with another GRDC-funded UQ PhD program being conducted at Kingaroy.”

Ms Wenham graduated from UQ with a Bachelor of Applied Science in mid-2011 and spent the early part of her career conducting a research project on behalf of the Peanut Company of Australia. This project investigated a group of soil-borne bacteria actinomycetes suspected of helping produce volatile compounds that cause off-flavours in stored peanuts in north Queensland.

Her transfer to the South Burnett was a return home, having grown up on a mixed cropping and grazing property near Kingaroy.

Although focussed on peanuts her PhD research work, promises to have implications for a number of crops with N. vasinfecta also affecting chickpeas and soy beans.

Other crop species have the potential to act as a non-susceptible host for the pathogen with results of pilot studies suggesting several cultivars of chickpeas, soy beans, mungbeans and cotton may host N. vasinfecta.

An experiment is currently underway to confirm the ability of cropping species to host the fungus while remaining asymptomatic.

Contact Details 

For Interviews

Kylie Wenham, PhD Student
School of Agriculture & Food Sciences
University of Queensland
(07) 4160 0744 / 0438 568 566
kylie.wenham@uqconnect.edu.au

Contact

Sarah Jeffrey, Senior Consultant Cox Inall Communications
0418 152859
sarahj@coxinall.com.au

GRDC Project Code GRS1-691

Region North

GRDC Project code: GRS1-691