Technology breakthroughs could lead to higher yields
Two new soybean breakthroughs could lead to better nematode control, resistance to fungi, higher calcium content and more uniform germination. As agriculture moves into the future and it becomes necessary to produce more on fewer acres, it is important to advance yield preserving technologies. Ram Singh, research geneticist with USDA–Agricultural Research Service (ARS) at the University of Illinois, and Jianxin Ma, associate professor of agronomy at Purdue University, have both discovered new opportunities for soybeans.
We could be saying “thanks” to this weed. More than 12 years of hard work lead to the successful cross between soybean variety Dwight and soybean’s cousin Australian perennial weed Glycine tomentella. Singh saw possible benefits to crossing these two plants for soybean farmers and lead the charge.
“I am excited to see when farmers will harvest this hard work. Sooner is better than later,” Singh says.
The new soybean cross could resist soybean cyst nematode and soybean rust. Field testing shows there also is a yield advantage. Since the cross was performed through natural breeding, it is technically non-GMO.
This difficult research is one-of-a-kind. Crossing soybeans with G. tomentella presented a variety of challenges, such as discovering the plants Singh created were sterile.
Soybeans have 40 chromosomes, and G. tomentella have 78. Hybrid plants with chromosomes from both parents contain 59 chromosomes, which causes them to be sterile, Singh explains.
“Subsequent backcrossing to Dwight produced 40-chromosome soybean plants after six years,” he says.
With 40 chromosomes, the plants can reproduce. But, with discovery comes new challenges, and Singh had to find a way to preserve pods and seeds.
“Not all seeds germinate; some die,” Singh says. And in research, a dead seed could kill years of hard work.
Singh found a method to create multiple plants from one seed—taking the error out of trial and error. Singh used growth hormone mixtures that help hybrid pod retention. He dissected the immature seeds and developed cultures to create multiple plants.
“If a plant dies, you don’t have a total loss,” Singh says. This method sped up his research and allowed for faster field testing. He could use this technology to continue testing without losing years of research time due to lost plants.
Randall Nelson, research geneticists with USDA–ARS and professor of plant genetics at the University of Illinois, works closely with Singh and led in-field research for the new soybean lines. The team started field testing seven years ago with 200 lines and continues today.
“A lot of unexpected things happen when we make these wide crosses,” Nelson says. “Lines are very high yielding relative to the soybean parent.”
A wild plant increasing yields might sound far-fetched, but Nelson and Singh have research as proof. However, these new soybean varieties won’t be widespread across farm country quite yet.
“It will be at least five to 10 years before there are commercial varieties,” Nelson says. “This summer, there are several soybean breeders crossing these lines with the best varieties. The test will be if they can obtain similar yield increases crossed with these very good varieties that we were able to get over Dwight.”
Continued research will also provide more details on what’s causing the yield increase.
“We don’t know anything about the yield genes,” Nelson says.
Are the yield increases in these lines coming from areas in the genetic code, previously shown to increase yield, or have they discovered a new area coming from G. tomentella?
Ultimately, Singh and Nelson want to see the new soybean cross in the hands of farmers.
Dedicated research led Jianxin Ma and a team of scientists to discover the major gene responsible for seed coat hardness and permeability.
While hard-headed people can be hard to deal with, hard seed coats are proving to be beneficial. Ma led a team of researchers to discover the gene responsible for hardness and permeability in soybean seed coats.
“It was not difficult to find the gene, but it took us nearly two years to develop a soybean population that allowed us to pinpoint the candidate for the gene,” Ma says.
“Then it took another two years to validate the gene’s function,” he adds.
This discovery helped the team determine how to increase calcium content to enhance soybean nutrition and potential benefits for southern and tropical regions.
“Making seed coats harder or more permeable may not affect productivity, but hardness can enhance the seeds’ viability and are thus preferred for southern and tropical regions, where soft seeds lose viability shortly after harvesting,” Ma says. “In addition, harder seeds appear to contain higher levels of calcium. This may pave a new strategy to meet the needs of calcium for kids when they cannot be provided by other sources.”
The hardness and permeability of the seed coat influences germination. In some areas, it is important to have an easily permeable seed coat. Some soybeans can start absorbing water within 15 minutes. In the South and tropical climates, tough coats are important to avoid seed damage at harvest.
This discovery could help enhance the genetic diversity of soybeans. As the team continues their research, they hope to find other minor genes influencing hardness and permeability so they can develop soybean coats to be best suited for various environments. This discovery could lead to acre specific seed coat prescriptions and possibly expanded to other crops.
“This could help researchers quickly identify genes controlling a similar trait in many other crops such as common bean, mungbean, chickpea and pigeonpea,” Ma adds.
It will take three to five years to start integrating this trait into soybeans and several more years to test the varieties before commercialization.
Advances in agricultural technology often move at lightning speed. Opportunities to increase yield and nutritional benefits are high priorities for many universities and seed companies. Watch for these discoveries and others to help meet the needs of people around the world.