Anatomy of the Bud Union in Mango (Mangifera indica L.)1

Abstract

Details of mango ( Mangifera indica L.) stem anatomy and formation of the bud union were observed in 4 combinations of 2 scions and 3 stocks chip budded at 5 stages of stock growth from first flush to 1 year old. ‘Haden’, ‘Saigon’, and ‘Turpentine’ stems of equivalent age and growth rate were indistinguishable anatomically. Four stages in formation of the bud union were: pre-callus, where 4 days after budding only a wound periderm was present; callus, where 8 days after budding proliferation from tissues mainly near the cambium resulted in firm attachment of the components; cambial bridge, where 12 days after budding cambial layers from stock and scion formed a bridge and vascular tissues were differentiated within 36-48 days; and, the healed union, where after 6-8 months several cylinders of new tissues were present and the lateral shift of the scion to align with the stock had begun.