National passionfruit breeding program (PF15000)

What was it all about?

Spanning from mid-2016 to mid-2020, this investment developed and evaluated new scion varieties of passionfruit to ensure the sustainability of the industry. The project worked towards the release of new commercial varieties before varietal decline affects the profitability of current ones such as Sweetheart and Misty Gem.

The project also selected and trialled rootstock and Panama varieties, as well as established an industry seedbank to conserve and enhance current passionfruit genetic material in Australia. Trial sites were established in both Queensland and New South Wales.

A linkage map was also constructed for one parent of the cross Tom’s Special x Lacey (TxL). This utilised funds from an SCU seed grant to carry out the DNA extractions and genotyping and to help discover useful markers for mass screening progeny.

Key activities from the program include:

Scion seedlings (crosses and selfs) trialled for new scion selections

More than 2200 first stage vines were planted, with 1750 being fully assessed up to mid-2020. Fifty-nine of these 1750 were taken on to second stage trialing. Only 14 vines made it through from first stage planting in 2016, to the third stage assessment in 2019, where around 760 grafted copies were made of these vines for trialing across nine grower sites.

Partial inbred lines produced from scion varieties

• Eighty-eight selfed Misty Gem seedlings were grafted and sent to North Qld in 2018. Three selections were made by grower, cloned and located in multiple copies at Alstonville in 2019. One of these has produced selfed seed (second generation of inbreeding).
• Vines and seed from first generation of inbreeding from the variety Lacey, from four first generation inbreds. Three second generation inbreds have been selected from Burringbar in 2019 and cloned and transferred to Alstonville.
• Seed from six inbred Tom’s Special (second generation of inbreeding).
• First generation inbred seed from another nine varieties: Misty Gem, P12-16-37, Tom’s Special, SP-16-22D, SP-16-36D, SP-16-59, SP-16-90, SP-16-72 and Sweetheart.

Rootstock and Panama trials

Only two of five trials in this evaluation provided useful data. These were the Bundaberg trial, which was large enough to produce useful results as well as the second Clothiers Creek trial site. Fruit yield counts were performed at both sites. More information and results from the Bundaberg site trial were reported in the Passion Vine Autumn 2020 edition on pages 18-19.

As a part of the work, an independent review of the breeding program was completed in early 2019 through the investment Technical review: national passionfruit breeding program (PF18000). This work provided 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 industry’s Strategic Investment Plan. Recommendations and their implementation are detailed in the Winter 2019 edition of the levy-funded The Passion Vine magazine.

ACT NOW

Read through the presentations delivered at the Passionfruit Australia Alstonville Field Day in July 2019:

• Presentation by Peter Bundock, Research Fellow (Plant Science) at Southern Cross University
• Presentation by Tobias Kretzschmar,Associate Professor (Plant Science) at Southern Cross University.

Several articles relating to the project were also released via the levy-funded The Passion Vine magazine, produce under the industry's levy-funded communications program, see below:

• See progress updates on the project on p12-14 in December 2016 edition
• Researcher Peter Bundock provided a detailed summary of recent project activities in the Spring 2017 edition
• Read about the progress of the project and the independent review which took place in late 2018 to early 2019 on p14 of the Winter 2019 edition
• More information and results from the Bundaberg site trial were reported in the Autumn 2020 edition on p18-19.
• An article on progress for her MSc has been prepared by Maddy Ianna for the Winter 2020 edition, see p28.

If you’re interested to learn more about this industry breeding work or would like to be involved in trials, email Peter Bundock at peter.bundock@scu.edu.au.