REGENERATION OF PLANTS FROM LONG-TERM ROOT CULTURE OF LIME, CITRUS-AURANTIFOLIA (CHRISTM) SWING

Excised root culture of lime, C. aurantifolia, was established in Mura shige & Skoog medium containing 3% sucrose. De novo shoot bud initiati on was recorded in basal medium at a low frequency during three years of continuous culture. The effect of indole-3-acetic acid and benzylad enine (BA) were investigated on root growth and shoot morphogenesis. I nclusion of BA in the culture medium had an important effect on root g rowth and shoot elongation: the frequency of shoot regeneration was on ly slightly improved by the growth regulator treatment. Shoot bud diff erentiation occurred at the proximal region of the root at or just dis tal to the cut end. Histology of shoot regeneration revealed the endog enous origin of the shoot buds from the pericycle tissue of the root. The regenerated plants contained normal diploid chromosome number (2n = 18) and have been established in soil.