Effect of etiolation on polyphenol oxidase activity in shoots of grape and its subsequent in vitro survival

Etiolation treatment was given to seven different grape genotypes after winter pruning to observe its effect on total phenols, PPO activity and on in vitro survival of shoots tips. Total phenol content and PPO activity was reduced dramatically in etiolated shoots over non-etiolated which was found to be genotypic dependent. Etiolation treatment ultimately resulted in marked increase in explant survival. Synergistic effect of genotype and etiolation treatment was found in lowering the endogenous level of polyphenol content, PPO activity and increasing explant survival in in vitro.