Vol. 12, Issue 3 (2023)

Author(s):
Matlooba Naseem, Chanda Kushwaha, Sinu Juneja and Surpati Anand

Abstract:
Investigations were undertaken to understand the effect of growth stages on peroxidase and total phenol production in three Brassica juncea genotypes after inoculations with Alternaria brassicicola. From the study, it was observed that peroxidase showed significant differences for growth stages among the genotypes after 18 hours post inoculation only. Among the genotypes, BRRM-101 and Varuna showed high level of peroxidase activity in comparison to PM-25. However, it was higher in BRRM-101 than Varuna at both the growth stages i.e., 0.974 folds and 1.213 folds greater at 40 DAS and 55 DAS respectively. The phenol production presented significant differences between the growth stages among the genotypes at 24 hours post inoculation while it was significant among the genotype only at 18 hours post inoculation. At 24 hours post inoculation, the activity of total phenol in partial resistant genotypes BRRM-101 was found 0.870 folds higher than Varuna at 40 DAS but was reduced at 55 DAS. This study indicates that total phenol likely plays an important role in later stages of defense response producing more stable secondary metabolites and peroxidase being short lived acts in early stages of defense response and is likely to be involved in signaling and induction of stable responses during pathogenesis.