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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #430788
Research Project: Breeding Stress Tolerant Soybeans, Regeneration and Evaluation of USDA Germplasm Collection,and Management of Uniform Soybean Trials

Location: Crop Genetics Research

Title: Multi-year evaluation and release of improved soybean lines for resistance to Phomopsis seed decay

Author
item Li, Shuxian
item Smith, James
item Gillen, Anne
item Read, Quentin

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2026
Publication Date: 8/24/2026
Citation: Li, S., Smith, J.R., Gillen, A.M., Read, Q.D. 2026. Multi-year evaluation and release of improved soybean lines for resistance to Phomopsis seed decay. PLOS ONE. 21(8):e0354166. https://doi.org/10.1371/journal.pone.0354166.
DOI: https://doi.org/10.1371/journal.pone.0354166

Interpretive Summary: Soybean is one of the most economically important oilseed crops grown in the world. However, soybean diseases not only affect yield, but also affect seed quality, resulting in significant economic losses. Phomopsis seed decay (PSD) causes poor seed quality and is one of the most damaging soybean seed diseases. In this study, seed assays were conducted to evaluate a total of 266 soybean entries in field experiments with inoculation of D. longicolla from 2019 to 2023. Results showed that over five years of testing, late maturity III soybean line 65-414-132-1 (DS65-1) had significantly less infection (38.58%) than susceptible late maturity III line LG03-4561-14 (86.21%). Early maturity IV breeding lines 14119-211-10 and 10031-243-12 (released as DS31-243) had lower percentages of PSD (29.86% and 46.59%, respectively) than susceptible early maturity IV line LD00-3309 (63.92%). Moreover, early maturity V line 10049-142-31 (released as DS49-142) had less percent infection (7.92%) than early maturity V entry AG5335 (25.38%); and late maturity IV 12060-260-2 (released as DS1260-2) had less percent infection (19.60%) than susceptible late maturity IV P46T59R (55.31%). All these resistant lines are recommended for use to develop soybeans with resistance to PSD. This research provides useful information for development of durable resistance to PSD and aids in the management of soybean seed decay during soybean production. This provides benefits to the U.S. soybean farmers and stakeholders.

Technical Abstract: Soybean [Glycine max (L.) Merr.] is one of the most economically important oilseed crops grown in the world. Soybean diseases not only affect yield but can also affect seed quality resulting in significant economic losses. Phomopsis seed decay (PSD) causes poor seed quality and is one of the most damaging soybean seed diseases. Diaporthe longicolla (syn. Phomopsis longicolla) and other pathogens in the Diaporthe/Phomopsis complex are the cause of PSD. Developing, releasing, and utilizing PSD-resistant cultivars is an economical and efficient strategy to protect soybean from PSD seed damage. The objective of this study was to identify improved soybean lines with PSD resistance and high seed quality after inoculation with D. longicolla in a 5-year delayed-harvest field trial. In this study, seed assays were conducted to evaluate a total of 266 soybean entries in field experiments with inoculation of D. longicolla from 2019 to 2023. Results showed that over five years of testing, maturity group (MG) late III 65-414-132-1 (DS65-1) had significantly less percentage of infection (38.58%) than susceptible late IIIs LG03-4561-14 (86.21%). Early MG IV lines 14119-211-10 and 10031-243-12 (released as DS31-243) had statistically lower levels of percent PSD (29.86% and 46.59%) than susceptible early MG IVs LD00-3309 (63.92%). These improved breeding lines were derived from PI 587982A. Moreover, early V 10049-142-31 (released as DS49-142) had less percent infection (7.92%) than early V entry AG5335 (25.38%), and late IV 12060-260-2 (released as DS1260-2) had less percent infection (19.60%) than susceptible late IV ‘P46T59R’ (55.31%). DS1260-2 was derived from PI 587982A, and DS49-141 was derived from PI 603756. All these resistant lines are recommended for use in developing soybeans with resistance to PSD. This research provides useful information for development of durable resistance to PSD and aid in the management of soybean seed decay during soybean production.