Fusarium wilt Tropical Race 4 research program (BA14014)
What’s it all about?
This project seeks to provide medium- and long-term solutions for banana growers to allow continued profitable production, should Fusarium wilt become widespread in the North Queensland banana industry.
Key goals of the project are to:
- Improve cultivar resistance, by developing and identifying TR4-resistant varieties
- Build resilient banana production systems, by developing a better understanding of the TR4 pathogen and its interactions with plants and soils
- Improve on-farm biosecurity practices.
The team reports progress across the three major streams of research into TR4, with key details below.
Regarding production systems…
This work aims to find out when the Fusarium wilt organism produces spores, how it survives in the soil and how it uses alternative hosts, to provide better management advice for avoiding spread of the disease. The researchers report:
- Spore production increases on dying plant tissue (either banana tissue or that of alternative hosts like weeds) even when they are sprayed with herbicide.
- An investigation of common weeds has identified 30 that can be alternative hosts of Fusarium wilt.
- Some plants are a poor host to Fusarium and initial screening has indicated that if they are grown in rotation with bananas, they can significantly reduce the amount present in the soil.
- In field experiments, rotation crops are being used to determine how long a Fusarium susceptible cultivar like Williams can survive.
- The role of good plant nutrition in making plants more disease tolerant is also being investigated. A lack of boron was found to make a plant more susceptible to Fusarium wilt, but variability in soil conditions has so far thwarted attempts to reduce the disease by manipulating micronutrients like iron.
- Different soil types have an effect on Fusarium, with higher clay soils found to be more suppressive to the disease than sandy soils.
- The team has identified the core microorganisms, fungi and bacteria of the banana microbiome (those consistently found across different soils, banana genotypes, plant ages and in bananas around world). Work will investigate their importance in the function of a healthy banana plant.
Regarding cultivar resistance…
To date, over 5000 plants from five different banana cultivars have been screened for improved resistance to the disease over their parents, as well as potential suitability for the Australian banana market. One cultivar, Dwarf Parfitt, had no improvements and has since been discarded from further evaluations.
Meanwhile, 41 improved cultivars will be further evaluated, while others are currently undergoing initial screening.
Regarding tools to facilitate biosecurity …
On-farm biosecurity remains a crucial part of the strategy for managing Fusarium wilt in Australia, and tools are being developed to help banana growers implement effective biosecurity practices.
The Quality Banana Approved Nursery (QBAN) scheme for banana planting material is being updated, allowing banana growers to have greater confidence in the planting material used to establish new fields. Also, the Best Management Practices for Biosecurity online tool is being rolled out, to allow growers to check their current practices and produce reports for their current situation.
- Read about the banana microbiome research and opportunities to suppress Panama disease.
- Find out more about what happens to soil organisms and banana production when nitrogen applications are manipulated.
- Learn more about Goldfinger evaluations and get further updates from the levy-funded Better Bananas
Regarding cultivar resistance…
In a recent project update to Hort Innovation, the research team report that the development of banana cultivars with improved resistance to TR4 is progressing, with the first of the new lines developed by mutation breeding initiating bunches. After nine months, none of the project’s mutated GCTCV119 lines have shown any symptoms of TR4, while the susceptible controls all have disease symptoms.
Goldfinger is a highly TR4 resistant banana cultivar that currently has poor consumer fruit acceptance. It has also undergone mutation breeding and, at the time of writing, the first bunches were appearing. The researchers note that developing improved eating quality of Goldfinger is a priority, before screening for TR4 resistance.
The project team note that the upcoming months will allow superior cultivars to be selected for further evaluation and other mutated cultivars to be tested.
Studies to determine the genetic markers for resistance to TR4 – which will allow banana breeders to select resistant lines – have shown a number of anomalies, including multiple disease resistance mechanisms and differences in susceptibility to different strains of Panama disease.
Regarding production systems…
The development of more resilient banana production systems is a key part of enhancing the suppression of TR4 for banana growers without the disease and, should TR4 become widespread, protecting partially resistant cultivars from exposure to continually high inoculum.
How Fusarium moves through the banana plant and survives between crops has been a large component of reducing disease inoculum. The researchers note that identification of alternative hosts, such as weeds, and their subsequent removal could reduce survival of the fungus. To this end, the results from studies on weed hosts are currently being developed into a manual for growers – look out for updates in industry channels and future editions of Hortlink.
Additionally, some crops or pasture could reduce the survival of Fusarium – and area that is currently being investigated in controlled glasshouse and field experiments.
The project team report that a key part of developing a TR4 resilient banana production system is knowing how the soil supports soil microorganisms to compete with Fusarium. Their research has involved characterising the banana soils of north Queensland for 81 different physical and chemical properties, with the soils currently being ranked on their ability to suppress Panama disease. The microorganisms that live in the soil, roots and within the plant are also undergoing characterisation to determine the core banana ‘microbiome’. Once the core microbiome is established it will be possible to determine how soil type, cultivar and management practices change the organism composition in relation to suppression of Panama disease.
Read more about the research in the update provided from p15 of the April 2018 edition of Australian Bananas magazine.
One important component of the project’s multi-faceted work is supporting access to clean planting material for the industry, with the transition of the Quality Banana Approved Nursery (QBAN) accreditation scheme from a state-government regulated program to one run by a partnership between the banana and nursery industries. The work involves a partnership between the Australian Banana Growers’ Council and Nursery & Garden Industry Australia, with QBAN transitioning across to the Nursery Industry Accreditation Scheme Australia (NIASA) and BioSecure HACCP certification. For more information on this project element, contact Rosie Godwin at firstname.lastname@example.org or NGIA’s John McDonald at email@example.com.
Banana growers are also set to have greater access to on-farm biosecurity tools, with development underway for a Biosecurity Best Management Practices app.
Check out the below resources relating to the project, including some from previous editions of Hortlink…
- This article from the December 2017 edition of Australian Bananas magazine, detailing the program’s work in developing banana varieties resistant to Panama disease (as well as work involving the Banana Plant Protection Program).
- This short video detailing a NextGen group visit to some of the project’s field trials in the Northern Territory, where the group went to learn about the ongoing screening work and the progress growers have seen first-hand. (The trip and video were part of industry development and extension program BA16007)
- This article on how Fusarium moves through the plant, part of the project team’s work in understanding the infection process of Fusarium.
Field and lab studies continue to develop (through cultivar irradiation) and screen varieties for TR4 tolerance/resistance, with some promising results to date. Watch this short video detailing a recent NextGen group visit to some of the field trials in the Northern Territory, to learn about the ongoing screening work and the progress growers have seen first-hand. This trip and video was produced under industry development and extension program BA16007.
The project team has also been progressing understanding of the infection process of Fusarium (see this article on how Fusarium moves through the plant), and its survival on alternative plants commonly found around banana plantations. Information on hosts is currently being compiled.
Initial studies on crops that may prove useful for rotation with bananas to reduce Fusarium has also been undertaken, with glasshouse screening taking place ahead of planting in the field trials in the Northern Territory.
Surveys of the north Queensland banana industry have also been undertaken to understand the physical, chemical and biological characteristics of soils, how this can be related back to inherent soil properties and banana management, and potential disease suppression. Watch this video looking at combatting the disease with soil management.
As reported in the last Hortlink, the project is also working on the Quality Banana Approved Nursery (QBAN) accreditation scheme, which is being transitioned from a state-government regulated program to one run by a partnership between the banana and nursery industries under this project. An update on this was provided on p8 of this issue of Australian Bananas magazine.
This is just a quick snapshot of project activities. Look for updates on the full breadth of project work in industry channels.
The project is currently conducting a series of lab and field studies, and is also working on the Quality Banana Approved Nursery (QBAN) accreditation scheme, which is being transition from a state-government regulated program to one run by a partnership between the banana and nursery industries under this project. An update on this is provided on p8 of the this issue of the Australian Bananas magazine.
This project is a strategic levy investment in the Hort Innovation Banana Fund