Plant Breeding and Biotechnology

Plant breeding is a science that creates crops with desirable traits such as high-yields, improved taste, and increased nutrition.

Such traits often evolve naturally from spontaneous mutations. However, this process is slow, and breeders often want particular combinations of traits that do not occur in nature.

Farmers can identify a desired trait in a wild species, and cross that plant with a domesticated plant variety. In such a cross, however, there is an equal chance that the progeny inherits undesired traits from the wild species. 

The use of biotechnology is beneficial for gene transfer in distantly related crops such as rice and daffodils that have many intermediate species and an extinct common ancestor. 

Traditionally, plant breeders would need multiple crosses laid over several centuries to transfer the necessary traits in the progeny. In contrast, modern biotechnologists can bypass multiple crosses to transfer the desired gene between these plants.

Biotechnology facilitates gene transfer between two different species, resulting in a unique phenotype.

For example, the broad-spectrum herbicide glyphosate inhibits a critical enzyme called EPSPS in plants.

Scientists created herbicide-tolerant maize by directly transferring a gene from the soil bacteria Agrobacterium to maize plants.

Crops that contain the bacterial gene for this enzyme are immune to the inhibitory effect of the herbicide. 

This genetic modification allows farmers to spray their fields with herbicide, killing competitor weeds that reduce yield while leaving the crop unaffected.