Vol. 12, Issue 3 (2023)

Author(s):
Pooja Upadhyay, AK Tewari and Himanshu Punetha

Abstract:
White rust or white blister disease caused by oomycete fungi, Albugo candia is one of the major devastating disease of rapeseed mustard. Continuous emergence of new pathogenic races is responsible for breaking down of the resistance of the already existing resistance cultivars. Certain biochemical compounds can be responsible for initiating the resistance response during the defense process of plants. For this, alteration of peroxidases and polyphenol was evaluated in selected Brassica genotypes at 24 hrs, 48 hrs, 72 hrs, 5 days and 9 days after inoculation (DAI). At 24 hrs post inoculation, maximum increase of peroxidase activity was observed in Wester (10.235 μmol tetra-guaiacol min^-1 mg^-1 protein) while minimum in susceptible cultivar Varuna (8.624 μmol tetra-guaiacol min^-1 mg^-1 protein). At 48 hrs post inoculation, maximum increase of peroxidase activity was observed in Donskaja (10.313 μmol tetra-guaiacol min^-1 mg^-1 protein) and minimum in Varuna (9.823 μmol tetra-guaiacol min^-1 mg^-1 protein) in control and inoculated plant respectively. Similar trend was followed at 48 hrs, 72 hrs, 5 DAI and 9 DAI. In total polyphenol activity at 24 hrs post inoculation, Donskaja showed maximum increase (2.52 gallic acid equivalents mg^-1 dry leaf) while minimum increase was observed in Wester (2.72 gallic acid equivalents mg^-1 dry leaf). Similar results were obtained at 48 hrs, 72 hrs, 5 DAI and 9 DAI. These biochemical parameters peroxidases and polyphenol can be established as biochemical markers for the identification of resistant sources against white rust.