|Wrather, Allen -|
|Chen, Pengyin -|
|Rupe, John -|
Submitted to: Southern Soybean Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 26, 2010
Publication Date: March 10, 2010
Citation: Li, S., Wrather, A., Chen, P., Rupe, J. 2010. Research Update on Screening Germplasm and Breeding for Resistance to Phomopsis Seed Decay in Soybean. Abstracts of the 37th Annual Meeting of the Southern Disease Workers, 2010. p.24 Technical Abstract: Soybean Phomopsis seed decay (PSD), caused by Phomopsis longicolla, is the major cause of poor seed quality in the United States, especially in the mid-southern USA. To identify soybean lines resistant to PSD, field screening of 135 selected soybean germplasm lines representing 28 worldwide origins and MG3-5 maturities along with PSD resistant and susceptible checks were performed in Arkansas, Missouri, and Mississippi. Prior to the field screening, thirty seeds of each line were assayed for incidence of P. longicolla and 100 seeds were tested for germination rate. Each entry was grown in a single 3-m row plot in a randomized complete block design with four replications. Seeds from each plot were collected when the plants were mature. A total of 200 seeds of each line were assayed for the incidence of P. longicolla and 400 seeds for germination tests. Preliminary results showed that incidence of P. longicolla was significantly different (P = 0.05) among soybean lines. Several lines were identified that had low disease incidence, good visual quality, and high germination rate. These lines will be confirmed for resistance in 2010 field trials. In addition, several advanced lines with PSD resistance derived from PI 80837 and PI 360841 were developed. These early-maturing lines with PSD resistance will be evaluated for adaptation and yield in 2010. Moreover, four F2 plant populations were derived from three different PSD resistance sources in attempts to pyramid different genes for PSD resistance from PI 91113, PI 360841, and PI 417479.