Biochemical basis of resistance to spotted pod borer, Maruca vitrata (Geyer) in Mungbean

Studies on six biochemical parameters, viz., total sugar, reducing sugar, non-reducing sugar, amino acids, proteins and phenols in pods in relation to the expression of varietal reaction towards spotted pod borer Maruca vitrata (Geyer) in ten varieties of mung bean revealed that highly susceptible cultivar LGG-450 had highest amount of total sugar (1.38 mg/g), reducing sugar (0.59 mg/g), non-reducing sugar (0.79 mg/g), amino acids (0.130%) and protein (23.44%) as compared to highly tolerant cultivar LGG-497 which had 1.13 mg/g, 0.48 mg/g, 0.65 mg/g, 0.072% and 18.56% respectively. Where as phenols were highest (21.03 mg/g) in resistant cultivar LGG-497 than the susceptible cultivar LGG-450 (20.00 mg/g). A significant and positive correlation exists between total sugar, reducing sugar, non reducing sugar, amino acids and proteins with pod damage where as negative correlation prevails between phenols contents in pod with pod damage. Free choice arena test also confirmed that highest larval orientation was observed in LGG-450 (susceptible) both in pods (17%) and flowers (14%) than the tolerant cultivar (LGG-497).