Ultrasonic treatment stimulates multiple shoot regeneration and explant enlargement in recalcitrant squash cotyledon explants in vitro.

Ultrasonic treatment (0.5-2 min) stimulated multiple shoot regeneration to high levels in vitro from recalcitrant cotyledon explants of commercial squash (Cucurbita pepo L.) cultivars Ma'yan and Bareqet, on Murashige and Skoog [Physiol Plant 15:473-497, 1962] (regeneration) medium augmented with 4.