Abayol, K. N.Ogaraku, A. O.Afuape, S. O.2023-12-142023-12-142011-02-01Abayol, K.N., A.O. Ogaraku & S.O. Afuape (2012). Effect of GXE Interaction on susceptibility of some advanced sweetpotato (Ipomoea batatas (L.) Lam) breeding lines at pre-release stage to Cylas spp. Journal of Natural and Applied Sciences, 2(1): 106- 114 Beninger, C.W., M.M. Abou-Zaid, A.L.E. Kistner, R.H. Hallett, M.J. Igbal,B. Grodzinsky, & J.C. Hall. (2004). A flavone and two phenolic acids from Chvsanthemum morifolium with phytotoxic and insect growth regulating activity. Journal of Chemical Ecology, 30:589-606. CAB International (1993). Distribution maps of pests. Series A: Map No. 278. Cylas formicarius (Fabricius). Map No. 279. Cylas puncticollis (Boheman). Map No. 537. Cylas brunneus (Fabricius). Dowd, P.F. & F.E. Vega. (1996). Enzymatic oxidation of allelochemicals as a basis for resistance against insects: Effects on the comleaf hopper Dalliulus maiclis. Natural Toxins, 4:85-91. Ellis, P.R. (1998). Exploiting the resistance in carrots and wild umbelliferae to the carrot fly Psila rosae (F.). Presentation IOBC/ Eucarpia Workshop Meeting, Dundee, Scotland, 14- 17 Sept., 1998.https://keffi.nsuk.edu.ng/handle/20.500.14448/6166The effect of phenolic acid on susceptibility of some advanced sweetpotato (Ipomoea batatas (L.) Lam) breeding lines to Cylas spp. was investigated at Nyanya, Nigeria. Sweetpotato genotypes were planted in a randomized complete block design (RCBD) with three replicates at the location. Results of Cylas infestation assessment showed that variation in susceptibility did exist among lines. Whereas ANOVA established significant difference (P<0.01) in levels of infestation expressed as percentage clean yield, a nonsignificant difference was observed in extent of individual root damage expressed as Cylas mean scores. Sound roots were picked at random and transported to the laboratory for phenolic acid determination. Total phenolic acid which was expressed as chlorogenic acid equivalent (CAE)/mg dry weight was found to differ considerably among breeding lines. The orange-fleshed line Centennial (2.05 mg/g dry weight) had the highest total phenolic acid while the white-fleshed line NRSP/05/3B (0.22 mg/g dry weight) had the lowest content. Also, separation of methanol extract of sweetpotato roots using silica-gel thin layer chromatography showed that only caffeic acid was present in two breeding lines - NRSP/05/022 and NRSP/05/1B. The large differences found in such a small germplasm collection suggest that selecting or breeding sweetpotato with high phenolic acid is possible. Further investigation was done to identify relationships among 16 variable traits using correlation analysis. Correlation studies showed significant relationship (P<0.05, P<0.001) between total phenolic acid and four variable traits. A highly significant relationship (P<0.001) between total phenolic acid and Cylas mean scores (r=0.43) indicate potential biological activity on Cylas spp. infestation thereby suggesting that total phenolic acid and indeed type of phenolic acid is associated with Cylas susceptibility among these breeding lines.eneffect, phenolic acid, advanced sweetpotato breeding lines, Cylas spp.Article