Bio-chemical basis in groundnut (Arachis hypogaea) resistant to leafminer (Aproaerema modicella)

Abstract

A bio-chemical study was conducted to assess the role of different plant-chemical constituents using groundnut
(Aeachis hypogaea L.) selections resistant ['ICG 5040','ICGS 2741','ICG (FDRS) 10','NC AC 17090' and 'GBPRS
312 (ICGV 86031),] and susceptible ('ICG 221', 'ICGS 44' and 'Robut 33-1 ') to leafminer [Aproaerema modicella
(Deveuter)]. 'ICG 5040' and 'ICGS 2741' exuded more sap on 'injury than the other selections at 20 days after plant
emergence under similar conditions. Bio-chemical analysis of complete plant-extracted sap at 50 days after plant emergence
indicated that resistant selections particularly' ICG 5040' and 'GBPRS 312' contained higher quantities of soluble
sugars, nitrogen (N) and polyphenols than the susceptible ones. Analysis of phenolic compouods of the sap samples
through'high pressure liquid chromatography from top 2 open leaves 20 days aner plant emergence indicated that the
concentration of these chemicals in the resistant selections was less than in the susceptible selection. However, resistant
selections were able to exude more sap, compensating for the low concentration of phenolic compounds in the sap.