Vol. 11, Issue 5 (2022)

Author(s):
Sunita Devi and Neelam R Yadav

Abstract:
To standardize the season for explants collection and sterilization protocol for getting success in micropropagation of guava cultivars because excessive exudation of phenols from cut ends caused lethal browning of explant and culture medium. Newly grown, young, disease free and fresh twigs were collected from well grown mother plants and selected as a source of explants in summer season (May-June) and winter season (Oct-Nov and Jan-Feb). Shoot tip and nodal explants (2-3 cm) were sterilized using different chemicals viz. citric acid, ascorbic acid, NaOCl, HgCl₂, KCl, bavistin and streptomycin etc. The explants collected in April-May showed minimum browning in Hisar Safeda and Lucknow-49. In shoot tip and nodal explants of guava, the minimum contamination was noted under treatment consisted of 0.2% each of bavistin and streptomycin (30 min) followed by 1% NaOCl (5 min.), 0.1% HgCl₂ (3 min), 1% KCl (3 min) and 70% Ethanol (30 sec). Results obtained from the study concluded that for successful in vitro regeneration, especially for difficult and recalcitrant tree species such as guava, is mainly dependent on the source and season of explants collection and the sterilization protocol.