|Damicone, J - OKLAHOMA STATE UNIV|
|Jackson, K - OKLAHOMA STATE UNIV|
|Dashiell, K - OKLAHOMA STATE UNIV|
Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2003
Publication Date: March 1, 2004
Citation: Damicone, J.P., Jackson, K.E., Dashiell, K.E., Melouk, H.A., Holbrook Jr., C.C. 2003. Reaction of the peanut core collection to Sclerotinia blight and pepper spot [abstract]. In: Proceedings of the American Peanut Research and Education Society, July 8-11, 2003, Clearwater Beach, Florida. 35:55-56. Technical Abstract: In 2001, entries from the peanut core collection, a subset of the USDA peanut germplasm collection, were planted in non-replicated plots in a field with a history of Sclerotinia blight. Variability existed among entries for reaction to Sclerotinia blight. Incidence of Sclerotinia blight approached 100% in several entries. Of the 745 entries evaluated, 10.9% were highly resistant (no disease) and 18.4% were resistant (1 to <10% disease incidence). Most of the highly resistant and resistant entries had an upright growth habit and were in maturity groups 2 and 3 (1=earliest, 6=latest). Sufficient seed was available for 74 of the 81 entries selected in 2001 for evaluation in replicated plots in 2002. Susceptible (Okrun), moderately resistant (Tamrun 96), and resistant (Tamspan 90) cultivars were included for comparison. Disease development was delayed in 2002 because row closure did not occur until late in the season. However, cool and rainy weather prevailed in October, which promoted late-season development of Sclerotinia blight that reached 44% in the susceptible cultivar 'Okrun'. Of the 74 entries, 20 were highly resistant and 30 were resistant. All of the highly resistant entries had an erect growth habit and were susceptible to pepper spot (Leptosphaerulina crassiasca), which developed to moderate and severe levels in 2001 and 2002, respectively. Of the entries that were resistant to Sclerotinia blight, entries (PI no.) 153339, 259639, 442724, 314817, 461451, 268891, 268903, 504614, 468195, and 290961 were also resistant to pepper spot. Only entries 268891 and 468195 were resistant to Sclerotinia blight and had a prostrate (runner-type) growth habit. Several of the entries that were highly resistant (502004, 268659, 313134, 313131) and resistant (259639, 442724, 313140, 461451) to Sclerotinia blight had yields that were similar to Tamspan 90. Selected entries that were highly resistant and resistant to Sclerotinia blight will be further evaluated in 2003, and germplasm from the USDA collection that is related to the selected entries will also be evaluated.