Effect of stock plant etiolation on in vitro phenol exudation during culture establishment of guava (Psidium guajava L.)

The cultural establishment for micropropagation of gurava especially Aneu-ploid No. 82 dwarfing rootstock was severely hampered by the browning phenomenon due to oxidation of phenolic compounds. Partial etiolation of stock plants of Allahabad Safeda and Aneuploid No. 82 rootstock before explant excision resulted in early bud sprouting and significant increase in explant survival. The lower degree of browning of culture medium was confirmed by recording the lesser amount of total phenol exudation into the medium.