One of the world's leading banana genetics experts says creating new varieties is at the heart of innovation in the banana industry. Dr Frederic Bakry told the Australia Banana Industry Congress that major steps have been taken in the domestication of hybrid varieties.
He was involved in setting up the French banana breeding program, at the agricultural research centre for international development, better known as CIRAD. By combining the crossbreeding and the development of cellular and molecular biotechnologies, he designed reconstructive breeding strategies aiming to mimic the natural paths of domestication of banana, by incorporating sources of disease resistance in the newly selected varieties.
"It creates sustainability, not just economic sustainability, but socio-economic sustainability," Dr Bakry said.
He noted that disease resistance varies between wild banana germplasm, and cultivated varieties. The wild forms tend to have frequent resistance to Panama disease Race 1 Yellow Sigatoka and Black Leaf Streak, while intermediate resistance to nematodes. Cultivated varieties have the same level of resistance to Panama disease Race 1, but intermediate resistance to Yellow Sigatoka, Black Leaf Streak and nematodes. As far as Panama disease Tropical Race 4 is concerned, resistance is rare in cultivated varieties, but Dr Bakry says it is not rare in wild germplasm.
The different cultivars are distinguished by the ploidy, which is the number of sets of chromosomes in a cell.
"Ladyfinger and Cavendish are sharing exactly the same AA chromosome content (the third set of chromosomes sets them apart)," Dr Bakry said. "So we use this knowledge to try to restitutre new varieties with this knowledge of the domestication of the banana."
He says CIRAD used a combination of triploid and diploid germplasm, and aimed to cross breed edible varieties with disease resistant fertile clones. So far Dr Bakry says there are 32-35 breeds.
One 'parent' that is used in numerous CIRAD hybrids is the IDN 110 or Pisang Rejang, which is an edible diploid and strategic genetic resource. It is resistant to Yellow Sigatoka and Black Leaf Streak, as well as Panama disease Race 1, and in controlled conditions, TR4.
In 2014, CIRAD sent six AAA advanced selections, chosen to suit the tropical conditions, were sent to Australia for field evaluation. The results were varied, with resistance to Yellow Sigatoka, Black Leaf Streak and Panama disease Race 1, but different patterns for TR4 and nematodes, and the fruit quality was also variable.
He concluded by saying that genetic breeding is an important part of the banana industry, and commended the Australian growers' council for prioritising the development of new varieties, combined with improved pest and disease management to improve industry biosecurity. But says it’s important further research continues.
"Using our knowledge we are trying to recreate the Cavendish," Dr Bakry said. "We need true perspectives by the crosses for FOC (Panama disease) Race 1 and TR4 resistant hybrids from a wide genetic background. We need to go for research of additional sources of resistance in wild and edible diploid germplasm. We have a need for pre-breeding and inheritance studies of new resistant genes at various ploidy levels."