Submitted to: Biological and Cultural Tests for Control of Plant Diseases
Publication Type: Research Notes
Publication Acceptance Date: January 1, 2001
Publication Date: February 1, 2002
Citation: Thies, J.A., Fery, R.L. 2002. Reactions of regional cooperative southernpea (cowpea) breeding lines and checks to southern root-knot nematode race 3, 2001. Biological and Cultural Tests for Control of Plant Diseases (online) Report No. 17:V14. DOI 10.1094/C17. The American Phytopathological Society, St Paul, MN. Technical Abstract: Lines from the Regional Southernpea Cooperative Trial were evaluated for resistance to southern root-knot nematode, Meloidogyne incognita race 3, in a greenhouse test. The experimental design was a randomized complete block with four replicates. Each plot consisted of five seeds of an entry planted 10 cm apart and 2 cm deep in a greenhouse bench containing steam- pasteurized soil (2 parts sand: 1 part loamy sand). Nematode inoculum was cultured on Rutgers tomato (Lycopersicon esculentum) in the greenhouse. Eggs were extracted from tomato roots using 0.5% NaOCl. Seeds were planted on 25 Jun and the soil surrounding each emerged seedling was infested with ca. 3,000 M. incognita eggs suspended in 5 ml water on 29 Jun. On 16 Aug, the roots of the plants were lifted, washed, and evaluated for resistance to root-knot nematode using a 1 to 5 rating system, where 1 = 0 to 3% of root system galled or covered with egg masses, 2 = 4 to 25%, 3 = 26 to 50%, ,4 = 51 to 79%, and 5 = >80% of root system galled or covered with egg masses. The standard resistant and susceptible check cultivars performed as expected. Seven observational lines (US-1070, ARK 96-1022, TX 123 BE, TX 158 BEgc, TX 160 BEgc, TX 158 PEgc, and TX 162 PEgc) and nine advanced lines (US-1033, US-1035, US-1036, ARK 96-918, TX 139 CRM, TX 148 PEgc, TX 149 PEgc, TX 159 BEgc, and TX 164 PEgc) were resistant (R), similar in reaction to the resistant check Mississippi Silver. Nine observational lines (US-1031, US-1032, US-1068, US-1069, ARK 98-348, ARK-95-356, LA 92-86, LA 95-62, and LA 96-7,) and five advanced lines (US-904, ARK 92-574, TX 128 BE, LA 92-180, and LA 96-21) were susceptible (S), similar in reactions to the susceptible checks Early Acre, Coronet, Arkansas Blackeye #1, Pinkeye Purple Hull, and New Era.