Arabic version: مكاديميا برية تحمل أملاً وراثياً

According to The Guardian, wild macadamia trees in the rainforests of south-east Queensland and northern New South Wales could provide vital genetic material for protecting the commercial crop. Macadamias are now a $2bn global industry, but all four species are native to a small area of Australian subtropical rainforest, much of which has been lost.

Macadamia integrifolia, M. tetraphylla, M. ternifolia and M. jansenii are the four species. The first two are grown commercially, while M. ternifolia and M. jansenii are wild, rare and almost inedible. Genetic testing has shown that a M. integrifolia tree near Mary’s Creek is the genesis tree of 70% of commercially grown macadamia trees worldwide.

Australia began commercial macadamia production in the 1960s, after cultivation had started in Hawaii in the 1920s. Ian McConachie, 90, says the crop is only two to three generations removed from the wild, leaving much unknown about wild trees’ potential. He has spent decades documenting them in remnant rainforests.

More than 80% of the habitat in which the trees evolved over 120m years has been reduced to remnants. M. jansenii is seriously endangered, while the other three species are listed as threatened or vulnerable. Conservationists say wild trees face invasive cat’s claw creeper, storm damage, clearing and pressure from development.

Denise Bond, executive director of Wild Macadamia Conservation, said cultivated trees have far less genetic diversity than wild populations. The remaining trees could offer traits for climate and disease resilience, including breeding resistance if pests, disease or root rot threaten commercial orchards. McConachie said a future goal is to store wild macadamia genetics for breeding and conservation.