Morphological and biochemical basis of tolerance to bruchid, Caryedon serratus (Olivier) in groundnut pods
Rekha G, Gopala Swamy SVS and Sandeep Raja D
Groundnut genotypes were screened for their relative tolerance to bruchid, Caryedon serratus (Olivier). Morphological characters and biochemical constituents of pods were studied to understand their contribution towards susceptibility to the bruchid. The genotypes viz., Narayani and K 9 were found to be less preferred by the bruchids for oviposition (20.33 and 21.0 eggs/100 g pods respectively) and resulted in emergence of significantly lower number of adults (13.67 and 14.33 adults respectively). Whereas, the highly susceptible genotype, ICGV 350 that possessed smooth reticulation received 47.33 eggs/100 g pods and resulted in emergence of 40.33 adults. Major contribution for tolerance to groundnut bruchid was found with the pod reticulation, wherein the less susceptible genotypes possessed prominent reticulation. The biochemical analysis also revealed that these genotypes possessed higher amounts of proteins (25.77 and 24.53%), ash (3.80 and 3.80%), total phenols (254.16 and 313.46 mg/g), pod surface phenols (268.14 and 317.97 mg/g) and lower total soluble sugars (3.55 and 3.84%) respectively when compared to susceptible genotypes. Thus, resistance to groundnut bruchid is a complex mechanism governed by both morphological and biochemical characters of pods.