Database Research Summaries
Improving Drought Adaption by Insertion of Limited Transpiration Trait Into Soybean Varieties in the Upper Mid-South of the US

calendar_today Year of Research: 2018
update Posted On: 05/23/2019
group Avat Shekoofa (Principal Investigator, University of Tennessee)
bookmark United Soybean Board

Research Focus

The focus of this project is to establish a protocol for phenotyping a wide diversity of genetic material for identification of expression of the limited transpiration trait (TRlim) under high vapor pressure deficit (VPD) leading to identify drought tolerant soybeans in the upper mid-south of the United States.


  • Identify candidate varieties (~100 lines) for screening in each of the breeding and commercial lines.
  • Screen lines using sensitivity to feeding silver ions (DTR, TRlim trait related).
  • Direct measurement of the transpiration under high VPD among the selected lines based on the result of feeding silver ion. Also, select lines that one or both expressed the TRlim trait as parents and initiate crossing.


  1. Among 92 RILs, half of the population showed higher sensitivity to silver ion than KS4895 (a parent of RILs). However, several lines showed no or limited changes in water loss with the silver treatment, and these may be candidates for a direct measurement of plant water loss under different humidity levels.
  2. One out of two parents in each population RILs (KS4895) and TN lines (T5601), showed the least sensitivity to silver nitrate treatment.
  3. Diversity among soybean lines in the RIL population in response to the silver treatment was clearly shown. Nine RIL lines were identified that were less sensitive to treatment with silver. There are nine lines that are candidates for direct measurement of plant water loss under different humidity levels (TR vs high VPD).
  4. Based on the preliminary leaf temperature data, screening soybean lines using leaf temperature under dry air (high VPD=3 kPa) can be a considerable tool. However, further studies are needed.


  • This research will contribute to our understanding of how soybeans cope with less than optimal water, and create a library of traits to choose from when breeding new cultivars.

For more information about this research project, please visit the National Soybean Checkoff Research Database.

Funded in part by the soybean checkoff.