National passionfruit breeding program (PF15000)
What’s it all about?
Established in mid-2016, this three-year investment is developing and evaluating new scion varieties of passionfruit to ensure the sustainability of the industry. It is working towards the release of new commercial varieties before varietal decline affects the profitability of current ones such as Sweetheart and Misty Gem.
The project is also selecting and trialling rootstock and Panama varieties, as well as establishing an industry seedbank to conserve and enhance current passionfruit genetic material in Australia.
The work has trial sites in both Queensland and New South Wales.
An independent technical review of the passionfruit breeding program was recently undertaken through the investment Technical review: national passionfruit breeding program (PF18000). The review was commissioned by Hort Innovation on the advice of the passionfruit industry's Strategic Investment Advisory Panel (SIAP).
The aim of the review was to provide recommendations to Hort Innovation and industry regarding the program's ongoing capacity, technical capability and implemented breeding strategy for the delivery of outcomes identified in the Passionfruit Strategic Investment Plan (SIP), which you can access from this page.
The review process commenced in December 2018 and concluded in February 2019. The review was conducted by an independent reviewer. During the review process, more than 30 stakeholders were engaged through open-table forums and one-on-one interviews. This included 27 growers and industry members across northern New South Wales, South East Queensland, and North Queensland.
The reviewer has since presented findings and recommendations to Hort Innovation and members of the passionfruit SIAP. These have been considered holistically in view of grower expectations and the delivery of outcomes identified by the SIP.
Hort Innovation has commenced discussions with the breeding program's research team at Southern Cross University to implement the recommendations suggested by the independent review to deliver outcomes to growers.
The project continues to assess trial plantings of crosses for new scion varieties. From the 2016/17 work, 29 promising scion variety selections from an original 580 were identified and selected for grafting onto rootstocks and subsequent planting at three of the project’s trial sites, where further assessments are taking place. At the time of writing, an industry group had recently conducted a scoring exercise, with results to be analysed and added to results from grower trials.
In relation to grower trialling, four of these 29 selections – identified as being the very best from early assessments – were distributed to a selection of growers for further analysis.
Reminder: if you have a trial pack remember to check in with the Southern Cross University team about how the selections are performing.
As reported in the last edition of Hortlink, the rootstock and Panama sub-project, added to the project during 2017, is trialling different rootstock and Panama varieties and crosses to compare their performance in the field. An initial trial of 95 vines is ongoing at the project’s Duranbah site to look at uniformity and suitability of some rootstock/Panama lines. Resistance to Fusarium for a number of lines is also being determined for 42 vines at Burringbar. Trialling of selected lines will also take place on growers’ properties to see if some rootstocks (grafted to scion varieties) perform better than others and which Panama lines perform best. Look for updates in industry channels and in Hortlink as this work progresses.
Other components of the project include…
- DNA work. The project is working to identify DNA markers that may be useful in breeding and selection work – essentially seeing if there are associations between particular pieces of DNA and traits of interest. Most recently, a family of vines produced by crossing Sweetheart and Pandora varieties has been selected for genetic analysis, along with DNA from the rootstock and Panama varieties in the project’s trials. Previously, a family of vines produced by crossing Tom and Lacey varieties was analysed, with the researchers finding some good association between DNA markers and traits related to fruit quality including sugar content, fruit weight and colour. If identified associations hold up under further analysis, this will enable the breeding program to select for these beneficial genetic traits in the work towards new high-performing varieties.
- The industry seedbank. The project continues to add seed to this important industry resource, with nearly 300 accessions of passionfruit seed now added.
If you’re interested to learn more about this industry breeding work or would like to be involved in trials, email Peter Bundock at email@example.com.
The project continues to monitor trial plantings of crosses for new scion varieties. ‘Stage two’ trial plants (grafted selections) are also being monitored. Twenty-nine selections were made from the 2016 crosses that have had tips grafted and are planted at Burringbar and Duranbah in New South Wales. Four of the best from these went out to some growers as a trial pack in October last year and are now bearing fruit.
Reminder: if you have a trial pack and have had time to assess the vines in some way (for example, for fruit suitability), the Southern Cross University team would like to hear from you.
The project has also been working to identify DNA markers that may be useful in breeding and selection work – essentially seeing if there are associations between particular pieces of DNA and traits of interest. Looking at the DNA of a family of vines produced by crossing Tom and Lacey varieties, the researchers have found some good association between DNA markers and traits related to fruit quality including sugar content, fruit weight and colour. There is further work needed to validate the findings, but if the associations hold up, this will enable the breeding program to select for these beneficial genetic traits in the work towards new high-performing varieties.
The rootstock and Panama sub-project, added to the project during 2017, is trialling different rootstock and Panama varieties and crosses to compare their performance in the field. An initial trial of 95 vines has been set up at Duranbah to look at uniformity and suitability of some rootstock/Panama lines. Resistance to Fusarium for a number of lines is also being determined for 42 vines at Burringbar. The project plan is to trial selected lines on growers’ properties to see if some rootstocks (grafted to scion varieties) perform better than others and which Panama lines perform best.
Get involved in the project’s trials! The research team is currently looking for growers to trial vines on their properties. This year the team would like to get 700 seedling vines for scion variety trials planted out on properties in Northern New South Wales, South East Queensland and in the Wide Bay area. If possible, a minimum of 100 vines at each property should be planted for logistical reasons when it comes to vine assessment time.
For rootstock and Panama trialling, the project is also seeking growers in these same regions to trial 1400 vines for the rootstock trial. There would also be nearly 500 Panama-type vines to trial by growers from Wide Bay to North Queensland.
If you’d like to be involved, email Peter Bundock at firstname.lastname@example.org.
Researcher Peter Bundock provided a detailed summary of recent project activities for the spring 2017 edition of The Passion Vine magazine, produced under the industry’s levy-funded communications program. Check out this breeding program update on p8 here.
The researchers report that many crosses and selfs of passionfruit varieties have been carried out, most recently for the new Panama and rootstock part of the program. The seed from these crosses and selfs are now to be planted to see if they have the qualities the program is after. Later on, the project team will be seeking volunteers to be involved in wider trials here.
The project team have also recently started the process of evaluating first-stage trial plants from last year – seedlings planted out in 2016 – to see if there are any likely candidates for further trialing on growers’ properties. While doing this, the team will be on the lookout for any crosses in which there is variation for traits of interest. These populations might be used in the future for developing DNA markers. The researchers will also be looking at the stage-two trials (grafted selections) from last year to see how they are performing. They report that there were a few good-looking vines from the 2016 seedlings in the Tom x Lacey crosses planted at Burringbar – with a hopeful eye being kept on these.
An initial genetic linkage map has been developed based on approximately 180 vines of the Tom x Lacey cross planted on two grower properties, and fruit is currently being assessed for pH, Brix, colour and other features. The goal is to see if DNA markers can be found on the linkage map that are associated with these traits. If the project team can find a few traits with good markers, then this should help in the future to select good candidate vines at seedling stage.
Back in December, a quick questionnaire for passionfruit growers was distributed to gather information on experiences and issues with current varieties, to guide trial locations, and to establish grower willingness to take part in trials. The survey remains open until the end of March, and all growers are encouraged to take part here.
In regards to genetic analysis to identify fruit quality characteristics and other desirable traits, there has been the establishment of a ‘mapping population’ and cloned/grafted plantings for this purpose. The initial plants are a cross between two former commercial varieties, Tom’s Special and Lacey. An early assessment of variation in fruit colour, fruit pulp sugar content and pulp pH has taken place, with results indicating a strong genetic contribution to the traits of pulp sugar content and pH.
At the time of last reporting to Hort Innovation, the researchers had also worked with the Queensland Department of Agriculture and Fisheries to secure a number of passionfruit seeds held from previous levy-funded work.
This project is a strategic levy investment in the Hort Innovation Passionfruit Fund