Submitted to: Plant Pathology Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/25/2007
Publication Date: 10/1/2007
Citation: Wang, M.L., Pinnow, D.L., Pittman, R.N. 2007. Preliminary Screening of Peanut Germplasm in the U.S. Collection for TSWV Resistance and High Flavonoid Content. Plant Pathology Journal. 6(3): 219-226. Interpretive Summary: Peanut genetic resources are maintained at the USDA-ARS, PGRCU in Griffin, Georgia. Accessions with useful traits can be identified by screening and used by breeders to develop new cultivars. Tomato spotted wilt virus (TSWV) is one of the most threatening diseases in the U.S. and has caused severe yield losses in peanuts. Flavonoids (phytochemicals) have beneficial effect to human health. Resistance to TSWV and high content of flavonoids were screened for peanut germplasm in the U.S. collection. One accession highly resistant to TSWV and eight accessions moderately resistant to TSWV were identified. Three accessions with high quercetin content were identified. Two accessions with moderately resistant as well as high quercetin content were identified. These accessions will be useful breeding materials for developing new peanut cultivars.
Technical Abstract: Extensive genetic variation exists within peanut germplasm. For a small-scale screening of resistance to tomato spotted wilt virus (TSWV) and flavonoid content, twenty-four accessions were selected from peanut germplasm in the U.S. collection and planted in the greenhouse. Plant response to TSWV was observed and recorded. Leaf tissues were collected and tested by an enzyme-linked immunosorbent assay (ELISA) for TSWV. Harvested seeds from mature plants were used for quantification of flavonoid content by high performance liquid chromatography (HPLC) analysis. Seed-coat colors were also recorded. One accession highly and eight accessions moderately resistant to TSWV were identified within Arachis hypogaea and confirmed by ELISA. Peanut seeds contained trace amounts of myricetin and genistein, and a low amount of daidzein and kaempferol whereas some accessions contained a high amount of quercetin. Intriguingly, all accessions with a high amount of quercetin had a white seed-coat color. There was no clear association between resistance to TSWV and amount of quercetin observed in the accessions evaluated in this experiment. To further investigate the association was discussed.