ARS | Publication request: Screening germplasm for resistance to phomopsis seed decay in soybean

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2010
Publication Date: August 7, 2010
Citation: Li, S., Rupe, J., Chen, P., Wrather, A. 2010. Screening germplasm for resistance to phomopsis seed decay in soybean. Phytopathology. 100:S70.

Technical Abstract: Phomopsis longicolla is the primarily cause of soybean Phomopsis seed decay (PSD), a major cause of poor seed quality in the United States. To identify new sources of soybean lines resistant to PSD, field screening of 135 selected soybean germplasm lines representing 28 worldwide origins and maturity groups 3-5 along with PSD resistant and susceptible checks were tested in Arkansas, Missouri, and Mississippi. Each entry was grown in a single 3-m row plot in a randomized complete block design with four replications. Frequent rainfall during seed maturation led to high levels of seed infection by a number of fungi. Significant differences in seed infection by P. longicolla occurred among soybean lines with some lines having no PSD while others had levels as high as 90%. These differences between lines were reflected in visual seed quality and in seed germination. Several lines with low disease incidence, good visual quality, and high germination rates at all locations will be tested for resistance in 2010 field trials.