Genetic research to advance next generation of apples

Local advances in genetics and genomics are driving the next leap in apple breeding, developing exciting new cultivars of naturally bred, premium quality, robust fruit for consumers.

Department of Primary Industries and Regional Development research scientist Sultan Mia is using genetic and genomic tools to breed resilient, high performance, tasty apples that are profitable to grow.

The research is being undertaken at the State Agricultural Biotechnology Centre in Perth and DPIRD’s Manjimup Horticulture Research Institute, as part of the Australian National Apple Breeding Program.

Dr Mia is using molecular marker technology to pinpoint desirable quality and disease resistance traits to breed Western Australian apples in four or five years less than the traditional 20 year breeding timeframe.

He said apples are bred by crossing two different apple cultivars to produce seedlings that carry a blend of characteristics from each of the parent lines.

“Molecular markers take the guess work out of crossing by being able to target economically important quality traits and disease resistance traits in each parent,” Dr Mia said.

“Quality characteristics include firmness, crispness and acidity, sweetness, storage performance and colour, while disease resistance traits cover tolerance to apple scab, powdery mildew and fire blight.

“Marker technology helps us to select seedlings with desirable characteristics and to cull inferior progeny just a few weeks after germination — saving costs, input, time and labour.”

Nine crosses were made last season with well known and novel plant material sourced from Australia, the United States, New Zealand and Japan to produce 1777 first generation seedlings.

Dr Mia is now using 16 DNA marker pairs to screen these seedlings and target eight quality and disease resistant traits.

“One of the interesting crosses has been designed to produce high quality yellow-skinned apples with contrasting red flesh, which has potential as both dessert and cider apple,” he said.

“Apples with red flesh can often be tart so molecular markers could also help overcome the challenge of dragging undesirable traits into new lines.”

The seedlings are now being grown out at the DPIRD nursery for ongoing evaluation, with promising lines set to be promoted to stage two in five years.

Further research is also underway to DNA fingerprint WA bred apples to establish identity profile of local cultivars at a molecular level.

“This will provide a ‘bar code’ for individual apples to demonstrate their genetic providence compared to the global cultivars,” Dr Mia said.

This work will be complemented by whole genome sequencing of DPIRD cultivars to better understand how local varieties differ from competitors’ apples to produce new cultivars that are uniquely Western Australian.

“Genomic mapping is like providing a ‘telephone book’ to identify where different traits are located and determine the relationship between traits,” he said.

“This information will help plant breeding take the best characteristics from our WA selections to generate superior new lines that capture consumer attention, while driving sustainable, profitable orchards.”