Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


First step to lasting wheat health

Substantial reductions in a deadly root disease of wheat crops and corresponding increases in yields of grain and straw mark a significant advance in the continuing war to protect the staple cereal from the ravages of the take-all soil pathogen, to which it is highly susceptible.

Researchers have now shown that careful selection of the variety of the first wheat in a new cropping cycle can reduce the disease's severity and increase yields in the second crop variety. Their findings are published in Scientific Reports.

Furthermore, these benefits are irrespective of the second variety or its susceptibility to this fungal pathogen. And though the findings relate to short rotations, in which the type of crop is changed after just two harvests, the benefits seem to continue for subsequent harvests.

"In rotation field experiments, we demonstrated the considerable and lasting impact of the choice of the first wheat variety on root health and the yields of the second wheat," says Vanessa McMillan, a plant pathologist at Rothamsted Research who led the study.

"There was a consistent reduction in take-all disease and a grain yield advantage of between 0.2 and 2.4 tonnes per hectare (or up to 25% of average UK yields)," adds McMillan. "The results were consistent across multiple field seasons and sites."

The research team had already identified and reported a new genetic trait in wheat, called take-all inoculum build-up (TAB); in spite of wheat's high susceptibility to take-all disease, there are low TAB varieties that minimise the presence of the pathogen in soil.

The team's latest findings show that using one of these low TAB varieties in Year-1 of a cycle generates the benefits for the second crop. The team is now investigating how lasting are these benefits in subsequent crops.

Take-all, caused by the soil-borne fungus Gaeumannomyces tritici, is the major root disease of wheat worldwide. Infection causes yellowing of crops and stunted growth, typically developing as patches that can spread throughout fields. Few chemical seed treatments are available.

Genetic traits, such as TAB, could provide a new way of combating take-all, particularly in association with cultural control techniques, such as crop rotation, within an integrated disease management strategy.

As part of the latest work, the team sampled commercial wheat varieties across a range of field sites from the AHDB Recommended List that demonstrated variation in TAB properties of modern wheats currently being grown by farmers in the UK.

"While there was evidence of significant interaction between the varieties across the trial sites, we could still identify a small number of low TAB varieties across all sites," notes McMillan, who also leads the take-all research group at Rothamsted.

Her group is currently investigating the potential mechanisms underlying the low TAB trait, including exploring whether low TAB varieties create an antagonistic rhizosphere environment against the take-all fungus.

Read the paper: Exploring the resilience of wheat crops grown in short rotations through minimising the build-up of an important soil-borne fungal pathogen.

Article source: Rothamsted Research.

News

Plant mothers 'talk' to their embryos via the hormone auxin

While pregnancy in humans and seed development in plants look very different, parallels exist -- not least that the embryo develops in close connection with the mother. In animals, a whole network of signals from the mother is known to influence embryo development. In plants, it has been clear for a while that maternal signals regulate embryo development. However, the signal itself was unknown -- until now. Plant scientists at the Institute of Science and Technology Austria (IST Austria), Central European Institute of Technology (CEITEC) and the University of Freiburg have now found that a plant hormone, called auxin, from the mother is one of the signals that pattern the plant embryo. Their study is published in Nature Plants.


Archaeologists discover bread that predates agriculture by 4,000 years

At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.


Climate change-induced march of treelines halted by unsuitable soils

New research from the University of Guelph is dispelling a commonly held assumption about climate change and its impact on forests in Canada and abroad.