Flooding for periods lasting as short as two days has been shown to reduce yields by as much as 27% during the early vegetative or early reproductive growth stages. Heavy rain in the early summer could make standing water in the field for several days, which would significantly damage farmers' fields by causing seedling emergence and establishment problems and impair/injure young soybean plants. In recent years, increase of floods from intense precipitation events was observed on a larger scale than in previous decades in the North central areas.
The best strategy to protect farmers from the ravages of flooding is release of new flood-tolerant soybean varieties and their integration into flood-tolerance management systems. PI Nguyen and co-PI Shannon have been actively researching the genetic basis of flood tolerance in soybean. With the proposed partnership among the University of Missouri, the University of Minnesota, and Iowa State University to work on this topic and prior work by members of this team, this NSCRP project is dedicated to solving this problem by taking advantage of the most active and successful breeding pipelines in the world for the release of flood-tolerant varieties.
Drought has become a significant problem that can affect farmers anywhere in the US. Drought stress can not only reduce yield, but also its components, oil, and protein as well as physiological processes such as nitrogen fixation. Drought resiliency in soybean has a short history of research and publication, beginning in the late 1980’s. Slow wilting, which was predicted to improve yield 75-85% under drought stress through a simulation model analysis, is a famous and reliable drought tolerance trait identified so far in soybean research and breeding community. Soybean breeders including Dr. Grover Shannon in this proposal have been developing drought-resilient germplasm and varieties. However, most of the breeding work has been conducted in late maturity groups (MGs) (late IV to VII). These developed drought tolerance traits need to be incorporated into the early MGs (0 to early IV) suitable for the North Central region of the US.
Thus, we propose to characterize soybean germplasm for early season flood tolerance to identify tolerant genetic resources and molecular markers for breeding applications and to develop new soybean varieties with drought and flood tolerance in maturity groups 0 to IV. The expected results will support sustainable soybean production and stabilize farm income in face of the increasing threat of flooding and drought stress in the North Central region.