Developing new resistant varieties
GCTCV119 mutagenesis trial

Latest update...

Unfortunately, in March 2018, tropical cyclone Marcus destroyed the GCTCV119 mutagenesis trial in the Northern Territory, with approximately 90% of the plant crop flattened. Work is currently underway in assessing the damage, with assessments likely to be delayed by 10 months.

Cyclone damage of GCTCV119 mutagenesis trial.

GCTCV119 overview

GCTCV119 is a Taiwanese Cavendish selection selected by the Taiwan Banana Research Institute (TBRI). It was developed using somaclonal selection from tissue cultured plants. Agronomic assessments at South Johnstone showed it didn’t perform as well as Williams Cavendish. It has a slower cycling time of approximately 15.1 months from plant to harvest, compared to Williams 10.6 months, and produces an average plant crop bunch weight of 20.4 kg, compared to Williams 29.1 kg. It is however known for its resistance to Panama disease tropical race 4 (TR4), and that is why it has been selected for mutagenesis. In the Philippines, better selections like GCTCV219 have been derived from GCTCV119. 

Trial progress

Mutagenesis, which is a breeding technique using gamma irradiation to increase  changes in tissue cultured plants, has been applied to cultivar GCTCV119. The aim is to improve the variety so that it retains tolerance to the disease and has improved agronomic characteristics.

The first step in this process was to determine how much gamma irradiation to use on this variety. Too much irradiation can severely damage or kill the plant, and too little may not induce sufficient changes to the plants. 

Experiments, known as dose response trials, have been conducted at the Maroochy Research Station and the sufficient dosage for GCTCV119 was determined. 

GCTCV119 was irradiated and stabilised, and over a thousand plants were sent to the Northern Territory where they were held in the nursery prior to planting. Plants showing structural deficiencies were removed from the nursery and not included in the trial.

791 plants were planted into the field (inoculated with TR4) in June 2017. Williams Cavendish and GCTCV119 plants, which had not been irradiated, were also planted as control plants to compare against. 

Unfortunately, in March 2018, tropical cyclone Marcus destroyed the GCTCV119 mutagenesis trial in the Northern Territory, with approximately 90% of the plant crop flattened. Work is currently underway in assessing the damage, with assessments likely to be delayed by 10 months.

Example of tissue culture that undergoes gamma irradiation treatment.
Gammacell chamber used to apply gamma irradiation to banana tissue culture.

This trial is part of the Fusarium Wilt Tropical Race 4 Research Program (BA14014). This project has been funded by Hort Innovation, co-investment from the Queensland Department of Agriculture and Fisheries, and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.