The history and science of lucerne breeding (part 1)

Date posted: 20 May 2016

Next time you visit Adelaide Botanic Garden, take a careful look at our lucerne-filled City Crop and imagine it’s thirsty… or cold… or covered in spots.

Have some sympathy for these poor little plants. They can’t get up and get a drink, or put on a jumper or get help from a doctor. They’re at the mercy of the elements.

Unless a farmer or keen horticulturalist is on hand, the plants must simply fend for themselves.

Lucerne, otherwise known as alfalfa (Medicago sativa) is a perennial flowering plant grown for its nutritious foliage. Historical records suggest that it originated in south-central Asia, was first cultivated in ancient Iran and was introduced to Greece in about 490 BC!

From its warmer, temperate origins, lucerne has been transported around the world for both livestock and human consumption. It arrived in Australia with the early colony, with farmers adopting one main variety (Hunter River). This variety became well adapted to Australia’s environment and grazing systems, but there was a little problem. Aphids.

In 1977 spotted alfalfa aphids wiped out the majority of the country’s lucerne crops. New varieties with inbuilt resistance and management options were needed. Enter plant breeders.

After over 30 years of breeding, Australian farmers now have access to over 50 different lucerne varieties. The new varieties have been developed with traits such as aphid tolerance, drought tolerance, disease resistance, improved nutrition and the ability to regrow quickly after grazing.

Plant breeders have worked to breed varieties which are better suited to conditions faced on-farm such as drought or low rainfall, hot winds, varying soil conditions and diseases. It’s all about developing varieties with the best possible package of genes possible because the tougher the plant is, the better they survive in the great outdoors.

With the help of science, lucerne has become one of the most successful forage crops grown in South Australia. In a good year, farmers can now produce up to 1.5 tonnes of seed per hectare!

That’s it for today, stay tuned for part two of this blog to learn how lucerne breeding is done.