Updated February 14, 2022:
1. Two NC lines, NC10-792 and N11-352, were confirmed as tolerate flood very well and are proposed for release by Dr. Fallen at USDA. N10-792 was the highest yielding line under flood conditions and received one of the lowest visual ratings, indicating good flood tolerance, in 2020. N10-792 also has performed well in the USDA regional trials across multiple locations and years.
2. The cloned gene (WLT1) was successfully incorporated into an elite soybean cultivar by marker-assisted backcrossing by Nguyen group at the University of Missouri. The derived lines with the gene showed significant yield advantage under flooding (40%) and low-phosphorus conditions (26%).
3. More 1,700 plants of upright cultivated types were selected from four wild soybean-derived bulk selection populations and are being advanced to F5 generation in the winter nursery. These four large F3 populations were growing in a large scale (1 acre for each) to select upright cultivated types of lines. F5 generation will be advanced for the selected ones and selection will be performed for flooding tolerance in 2021 and 2022.
4. The GDM seed company is making MTA to transfer a flooding tolerant elite germplasm from the University of Missouri. GDM is very interested in our flooding tolerance breeding. Currently, GDM is negotiate with the University of Missouri to transfer a flooding tolerant line: S12-1362. This line was developed by Dr. Chen’s breeding group with the aid of marker-assisted selection from Dr. Nguyen group. This line has two major flooding tolerance genes and showed consistent flooding tolerance across all the 5 testing states over past 3 years.
5. Collaborative research between the University of Missouri and the University of Arkansas has identified several new flooding tolerance genes in the diverse panel. GWAS identified a major flooding tolerance gene on Chr. 3 and several other genes with relatively smaller effects for the mid-season stress (R1 stage). We plan to publish the results in the summer of 2021.
6. Preliminary research showed seed composition is not significantly affected by flooding stress at R1 stage. Dr. Mozzoni from the University of Arkansas analyze protein, oil and sugar contents of 20 flooding treated lines and found no significant negative effects on these seed composition traits by flooding. We will confirm this results in 2021.

Updated February 14, 2022:
1. Breeding for new flooding tolerant/high yield germplasm and varieties is on the right track. New flooding tolerant genetic resources are being identified through our collaborative work.
2. Seeds for all proposed experiments have been distributed to all the locations and planting will be finished by mid-June. These include germplasm screening for flooding tolerance for the early season flooding, gene mapping populations, flooding tolerance stability test across all the locations and breeding populations and lines for flooding tolerance.
3. We developed a new phenotyping tool by using UAV-based imagery and deep learning to evaluate soybean responses to flooding stress. These results were published in the journal of Plant Phenomics.

Updated February 14, 2022:
Flooding and saturated soil stress is one of the major yield constraints in soybean production in the both early- and mid-season. This project aims to identify flood-tolerant genetic resources for early and mid-season flooding stress, accelerate the development of flood-tolerant varieties and germplasm, and optimize management practices to protect yield from waterlogging and flooding. Enhanced genetics and diversity in flood tolerance will be achieved by utilization of exotic and wild resources. The next-generation genomic breeding strategy assisted by digital phenotyping technology will be developed and deployed to accelerate soybean breeding for flood tolerance.
Until now, 1) Novel genetic resources were identified for both early- and mid-season flooding stress, including soybean germplasm lines, flooding tolerance genes and DNA markers; 2) New breeding lines were developed are being released as high-yielding germplasm with flooding tolerance; 3) 2 gene mapping and 4 breeding populations with wild soybean parents (wild bulk selection) were developed; 4) Effects of flooding on yield were quantified and raised-bed production strategy appeared to be promising; 5) Flooding at seed filling stage was found to negatively affect seed quality and composition.

Updated February 14, 2022:
Flood stress is becoming severe as a result of increased heavy precipitations in soybean growing areas. To support sustainable soybean production and stabilize farm income, this project aims to develop high-yielding/flood-tolerant varieties and fit these varieties into best management systems to mitigate yield loss due to flooding.
Our progress up to date is exciting, as soybean yield was increased by ~15 bushels/acre over currently available varieties when flooded. New flood-tolerant varieties were developed and are being improved by subjecting an array of wild and domesticated Asian soybean types to flooding at early- and mid- season, identifying the most tolerant types, and then using them as parental stocks in applied U.S. breeding. Those high-yielding and flooding-tolerant lines were released or being released for germplasm and varieties. Three best lines from the University of Missouri (Chen group) were transferred to a seed company (GDM Seeds) via a standard MTA and another MTA is currently being drafted with AgSouth Genetics to evaluate two flood tolerate lines from USDA-ARS, NC (Fallen group) for commercial production.
Our key to breeding success in this multi-state project is a large network of field sites for flood-tolerance screening and variety development. In addition, we are integrating our advances in flood tolerance with ongoing USB projects to transfer flood-tolerance to high-protein and high-oleic materials so that they are more stable and profitable in the farmer’s field. Breeding advances are being achieved by blending classical/genomic breeding approaches.