Soybean improvement through plant breeding has been critical over the years for the success of the crop.
In a new study that traces the genetic changes in varieties over the last 80 years of soybean breeding, researchers concluded that increases in yield gains and an increased rate of gains over the years are largely due to the continual release of greater-yielding cultivars by breeders.
"This research in some ways looks back and informs us how soybean varieties have changed. It's useful to document these traits and changes," said Brian Diers, a University of Illinois plant breeder and researcher on the study. "We can show that we really have been successful at increasing yield."
But this study is also about the future of the soybean crop.
"The study has actually created quite a lot of interest among soybean breeders because they want to understand what's happened, and when we look at physiological traits, we can see what has been changed. This gives us clues about what traits we should focus on in breeding for future increases based what has been inadvertently changed over time as we have selected for yield," he said.
Diers and a multi-institutional team of researchers evaluated historic sets of 60 maturity group (MG) II, 59 MG III, and 49 MG IV soybean varieties, released from 1923 to 2008, in field trials conducted in 17 states and one Canadian province during 2010 to 2011.
The experiments included plant introductions (PIs) and public cultivars obtained from the USDA Soybean Germplasm Collection housed at the National Soybean Research Center at the U of I, as well as from varieties provided by Monsanto, Pioneer, and Syngenta.
In the process of documenting the genetic changes, the researchers observed an increase in yields over the past 80 years that is equivalent to one-third of a bushel per acre per year increase.
Diers said that the researchers estimated that about two-thirds of the yield increases in farmer's fields are due to new varieties that breeders have introduced with the other third due to other reasons such as improved agronomic practices.
"When we compare old varieties to new varieties, the new varieties do yield much better than the old varieties. When we look at the data more closely, the yield increases have actually accelerated starting in the 1960s and 1970s. It's different for each maturity group, but current yield increases are greater than they were earlier," Diers said.
This research also showed that when compared to old varieties, plants in the new varieties are shorter in height, mature later, lodge less, and have seeds with less protein and greater oil concentration.
"The new varieties tend to mature later within these maturity groups, which is something that theoretically shouldn't happen because we classify these varieties based on when they mature. So theoretically MG II varieties should mature at the same time now as one back in the 1970s, but this is not the case," Diers said. "Probably over time, people have been selecting varieties that are a little bit later and later, and these changes have accumulated. In some ways, it's not a bad thing, because farmers are planting earlier than they did back in the 1970s so they actually need varieties that will mature later than back then. That's not a bad thing."
Other traits reported as changed over time included earlier flowering time, which has resulted in an expanded reproductive period. "We didn't know that this reproductive period was expanding, and we are now asking whether breeding for an even longer reproductive period could further increase yields. Other studies have looked at the interaction of planting date by year of release and have shown new varieties can utilize earlier planting dates better than old varieties," Diers said.
With soybean being a leading source of protein and oil for human food, animal feed, and other products, global rates of yield increases for the crop will need to keep up with demand in the future.
"By understanding how we've made these changes to date, it can help us understand how we can further improve yields and increase the rate of gain," Diers said.
Diers plans to study ways to increase the rate of genetic gains using more modern breeding techniques.
"Most of the yield increases are the result of breeders selecting better combinations of genes that can allow plants to take sunlight and produce more seed from that sunlight. We don't know what genes breeders are selecting that are resulting in these increases, for example, where in that pathway from the sunlight hitting the canopy to producing seed where this occurs. Breeders, by selecting new varieties that have more yield, are able to make this progress without really understanding the mechanism," Diers said.
The study, "Genetic Improvement of US Soybean in Maturity Groups II, III, and IV," was recently published in the Journal of Crop Science and can be accessed online at https://www.crops.org/publications/cs/view/first-look/c13-08-0579.
Co-authors of the study include Keith Rincker, Randall Nelson, James Specht, David Sleper, Troy Cary, Silvia R. Cianzio, Shaun Casteel, Shawn Conley, Pengyin Chen, Vince Davis, Carolyn Fox, George Graef, Chad Godsey, David Holshouser, Guo-Liang Jiang, Stella K. Kantartzi, William Kenworthy, Chad Lee, Rouf Mian, Leah McHale, Seth Naeve, James Orf, Vaino Poysa, William Schapaugh, Grover Shannon, Robert Uniatowski, Dechun Wang, and Brian Diers.
Brian Diers | EurekAlert!
How algae could save plants from themselves
11.05.2016 | Carnegie Institution for Science
Biofeedback system designed to control photosynthetic lighting
10.05.2016 | American Society for Horticultural Science
Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.
The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...
In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...
Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices
Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.
When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene
In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...
The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.
24.05.2016 | Event News
20.05.2016 | Event News
19.05.2016 | Event News
25.05.2016 | Trade Fair News
25.05.2016 | Life Sciences
25.05.2016 | Power and Electrical Engineering