Scientists isolate gene in wheat that increases crop yield

Researchers from the John Innes Centre in Norwich, UK, have isolated a gene that controls the size and shape of spikelets in wheat, which they hope could lead to an increase in crop yield.

The study focused on a mutant trait in bread known as paired spikelets, where a wheat inflorescence is formed of two spikelets instead of one.

The development could be an important contribution to feeding a growing population, with The Wheat Initiative, which coordinates global wheat research, estimating that floral architecture must be improved by a 1.6% yield increase to match demand.

“This paper is an example of what we are capable of doing in wheat now with a lot of the resources that are coming on board,” said John Innes Centre researcher Dr Scott Boden. “We have gone from the field to the lab and back again. This is a developmental gene that contributes to a lot of agronomically important traits.

“This knowledge and the resources that come from this study can be used to see if it really does benefit yield.”

Using techniques such as plant transformation, gene sequencing and speed breeding, researchers investigated wheat displaying paired spikelets, which were grown via multi-parent advanced generation intercross (MAGIC), in order to study and identify the genetic origins of relevant traits.

The research team discovered that the gene teosinte branched (TB1) regulates wheat inflorescence architecture and promotes the paired spikelets which could increase crop yield. This promotion occurs because of a mechanism that delays flowering and reduces the expression of genes that control the development of lateral branches, known as spikelets.

The team says that the underlying genetic mechanism they have discovered is also relevant to inflorescence architecture in a number of other major cereals including corn, barley and rice.

They also found that alleles modifying the function of TB1 were present in a wide range of major modern wheat cultivars used by breeders in the UK and Europe. Variant alleles for TB1 were also present on two of the three wheat genomes of winter and spring wheat.

Genetic analysis also showed that TB1 is linked to well-known gene Rht-1—also known as the Green Revolution gene—which controls plant height.

Further studies will determine whether some of the effects attributed to Rht-1 are actually TB1 effects.

“We have approached this in an academic sense but we have moved it towards giving breeders tools they can work with to optimise floral development,” said Boden.

The findings are available in the paper ‘Teosinte Branched1 regulates inflorescence architecture and development in bread wheat’, which was published in the journal The Plant Cell.