Wheat Genetics, Soil Sampling

New Methodology Speeds Improvement of Favorite Wheat Varieties

Wheat growers may have access to new and improved versions of their favorite varieties much sooner than usual thanks to new methodology developed by Kulvinder Gill, WSU professor and the Vogel Endowed Chair in Wheat Breeding and Genetics. Other WSU collaborators on the project are Drs. Kim Kidwell, Craig Morris and Xianming Chen.

Developing a new wheat variety can take from between nine and 11 generations using traditional methods, said Gill. The same is true for making minor adjustments to existing varieties. The challenge when adapting those to be more resistant to a new disease or pest is preserving the genetic background of the plant in the new version.

Gill and his research team used Zak, a spring wheat developed by wheat breeder Kim Kidwell who is now associate dean for academic programs in the College of Agricultural, Human, and Natural Resource Sciences, for their experiments. Using a new combination of genetic markers, he not only selected for increased stripe rust resistance, but also for preservation of the variety’s best existing traits.

The results? A more stripe rust resistant version of Zak developed in five generations with 97 percent of its original genetic makeup intact. That compares to nine generations to develop a more stripe rust resistant version of Zak with just 82 percent of its original genetic makeup intact using more traditional methods.

Gill and his team also have applied the new technology in different ways, including improving the emergence of winter wheat varieties. In addition, he is using it to help make winter, spring and club wheat varieties resistant to the imidazole class of herbicides that can then be used to effectively control grassy weeds.

Gill outlines the new methodology in an article recently published in the journal PLoS ONE.

For more information on Gill’s wheat genetics research, please visit: http://bit.ly/379r6q.

Revolutionizing Soil Sampling

David Brown is experimenting with sensors mounted on penetrometers to analyze soil directly in the field. Brown is a pedologist in the WSU Department of Crop and Soil Sciences.

“For so long, it was about digging soil pits, Then we moved to taking cores. Both were, and still are, labor and time intensive, taking upwards of a year to arrive at analyzed samples,” Brown said. “Imagine if we could characterize soils by simply sticking a probe in the ground! That completely changes soil science.”

Brown’s research project is focused on options for monitoring, measuring and verifying agricultural carbon sequestration systems.

The work is partly driven by the need to find cost-effective ways to measure soil carbon with regard to the market value of agricultural carbon sequestration and, consequently, the value of carbon credits paid to participating farmers.

His team has been simulating soil analyses by interrogating intact soil cores with visible near-infrared spectroscopy (VisNIR). This type of spectroscopy provides information on soil organic matter, texture and mineralogy. The core simulations will be used to check the accuracy of data derived with a penetrometer system from adjacent locations.

Their custom penetrometer is equipped with fiber optics and a quartz-sapphire side window that allows in-field VisNIR soil interrogation. The penetrometer’s tip will also measure physical resistance as it is driven into the ground using a truck-mounted Giddings hydraulic system.

Similarly, the team is also interrogating intact soil cores using laser-induced breakdown spectroscopy (LIBS). This cutting-edge technology uses a laser to “zap” the soil, creating a plasma that gives off light energy which is detected and translated to element data. Their plans are to also mount this sensor in a penetrometer system.

“Although engineering the penetrometer system is not easy, refining the spectroscopy is the major challenge,” explained Brown. Several variables, such as the amount of moisture in the soil, water vapor, and uneven soil surfaces, tend to complicate matters. Even in perfect conditions, the carbon peak or magnitude line shown in the LIBS emission spectra is not directly proportional to the amount of carbon in the soil. The peak is dependent on what other elements are in the soil.

“You can extract a core pretty quickly, but then all you have is a core,” said Brown. “Our ultimate goal is to have both LIBS and VisNIR sensors mounted in a single penetrometer.”