Welcome to GM in Australia, a The Conversation series looking at the facts, ethics, regulations and research into genetically modified (GM) crops. In this first instalment, Peter Langridge describes two GM techniques: selective breeding and genetic engineering.

GENETIC modification (GM) sounds very laboratory-based people in white coats inserting and deleting genes but the vast majority of GM work was completed in the field through selective breeding.

Early Middle Eastern farmers collected grain from natural grasslands, but they needed to time their harvest very carefully. If they were too early the grain wouldnt store well, and if they were too late the grain would spread over the ground making collection difficult.

At some stage, one of these early farmers must have noticed that some heads remained fixed on their stems even after the grain was fully dry. He obviously didnt understand this at the time, but these were plants with a mutation in the genes controlling seed dispersal.

Farmers began preferentially choosing plants with this useful mutation and planting them, perhaps the first case of breeding and selecting for a novel trait.

Gregor Mendel.

Wikimedia, CC BY

Systematic breeding really began in the early 1900s when scientists rediscovered Silesian monk Gregor Mendels groundbreaking work on genetic inheritance in peas.

Breeding involves utilising genetic variation to produce new combinations of genes and gene variants. A breeder will cross two different lines and then select offspring that have improved performance.

More:
GM: from the field to the lab

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