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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #314904
Title: Evaluating soybean cultivars for resistance to Phomopsis seed decay in Mississippi

Author
item Li, Shuxian
item SCIUMBATO, GABE - Mississippi State University

Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/8/2015
Publication Date: 8/1/2015
Citation: Li, S., Sciumbato, G. 2015. Evaluating soybean cultivars for resistance to Phomopsis seed decay in Mississippi. APS Annual Meeting. 346-P.

Interpretive Summary:

Technical Abstract: Phomopsis seed decay (PSD) of soybean reduces seed quality, germination and seedling vigor. PSD has been problematic in most soybean production areas including Mississippi (MS). Planting resistant cultivars is one of the most effective means to control PSD. However, very few soybean cultivars resistant to PSD are currently commercially available for planting in the US. In this study, 16 commercial soybean cultivars were evaluated for resistance to PSD with inoculated and non-inoculated treatments and two harvest times at R8 and R8+2 weeks growth stages (on-time vs. delayed harvest) in Stoneville, MS in 2012 and 2013. Those 16 cultivars were chosen based on the data from seed assays of 50 commonly planted cultivars in 2011. Significant differences in seed infection by Phomopsis longicolla, the causal agent of PSD, were observed among cultivars tested. Seed infection ranged from a low of 6% to a high of 76%. These differences among cultivars were also reflected in visual seed quality and seed germination. In general, inoculated plots had higher seed infection than the non-inoculated plots. Morsoy R2 491 had the lowest percentage of Phomopsis seed infection and highest germination rate in both harvest trials. However, some cultivars had low Phomopsis seed infection in the on-time harvest trial, but had high Phomopsis seed infection in the delayed harvest trial. Testing of cultivars at delayed harvest time or under the conditions which favor PSD disease development is important for identification of PSD-resistant cultivars.