POLYPHENOL OXIDASE ACTIVITY AND PHENOLIC CONTENT PATTERN DURING SHOOTDEVELOPMENT OF GRAPE (VITIS-VINIFERA L) IN DIFFERENT GROWING SEASONS

The PPO activity and content of phenolic compounds were estimated duri ng the different growing seasons and developmental age of shoots in se ven grape genotypes. Both, the total phenol content and catecholase ac tivity were found significantly affected by the growing season, develo pmental age of shoot and the genotype. But, season as well as age of s hoot could not influence cresolase activity. Spring as season; 30 days of sprouting as age; Gold and Anab-e-Shahi as genotypes were found be tter in comparison to summer as season and 15 days of sprouting as age in respect to level of phenols and PPO activity.