Heat treatment for enhanced responsiveness of dorman axillary buds of pineapples

Abstract

Explants 3-5 mm in diameter, consisting of dormant axillary buds and adjacent stem tissue, were excised from the stem region of the crown, disinfected, rinsed and immersed in distilled water at 60 deg C for 6 or 8 min before transfer to liquid or semisolid nutrient medium. Controls were placed into the nutrient medium after disinfection. Immersion in hot water significantly increased percentage bud responsiveness (change in colour from cream to green) and shoot emergence after 4 weeks compared with controls. This technique allowed bud release from dormancy to be synchronized to a 3-week period (from the end of the first week to the beginning of the fourth week) and significantly reduced the time required for release from dormancy. The response of heat-treated buds was greater in liquid than semisolid nutrient medium.