Micropropagation of rhubarb with special reference to weaning stage and subsequent growth

Abstract

Micropropagation of rhubarb (Rheum rhabarbarum L.) on MS medium with sucrose 20 g/l and agar 8 g/l, supplemented with benzylaminopurine (BAP) 1 mg/1 and indolebutyric acid (IBA) 1 mg/l for initiation and multiplication, was studied with cv. Victoria and clone AF. With clone AF, the effects of rooting method (direct rooting, direct rooting with Floramon A or in vitro rooting) and propagule size (height 1.5-2.0, 2.1-5.0 or 5.1-10.0 cm) on weaning survival and plant size were examined. Further growth was recorded over a 3-year period in field studies. The medium gave a multiplication rate of 3.2/4 weeks for clone AF. For cv. Victoria, the medium did not seem suitable because of high occurrence of callus and vitrification. The multiplication rate of cv. Victoria was, however, increased from 2.8 to 5.4/4 weeks by using propagules from non-sprouting instead of sprouting buds. The weaning survival of clone AF averaged 86%. Rooting method did not affect either weaning survival or plant size. Propagule size affected plant size, but not weaning survival or further growth in the field.