Bud scale maturation in saskatoon berry (Amelanchier alnifolia Nutt) plantlets following in vitro hormonal treatments

Bud scale maturation represents one of the early steps in endodormancy induction. Since abscisic acid (ABA) has been associated with dormancy, the role of this and other phytohormones in the maturation of bud scales was examined. Maturation of bud scales was achieved in vitro in saskatoon berry (Amelanchier alnifolia Nutt.) plantlets with a combination of 50 mu M ABA and 5.5 mu M 6-benzylaminopurine (BAP). Abscisic acid alone did not induce bud scale maturation but the greatest inhibition of bud break occurred under ABA treatments despite the addition of growth-promoting phytohormones. Unlike BAP, anaphthaleneacetic acid (NAA) was ineffective in counteracting growth inhibition due to ABA treatments. The absence of NAA, however, was a requirement for bud scale maturation.