FORMATION OF VASCULAR BUNDLES IN BULBLETS REGENERATED FROM SCALE OF LILIUM-JAPONICUM THUNB. IN-VITRO

In vitro experiments were conducted to clarify the process of forming the vascular bundle system in regenerated bulblets from the mother sca le of Lilium japonicum Thunb. cultured on MS medium. The medium contai ned 0.2mg.liter(-1) alpha-naphthaleneacetic acid (NAA) and 0.01mg.lite r(-1) benzyladenine (BA) or 0.01mg.liter(-1) NAA and 2.0mg.liter(-1) B A or no plant growth regulators. There were one major and two minor va scular bundles in the scale of the bulblets cultured for 8 weeks in vi tro. A collateral vascular bundle (CVB) exists in the scale and in the basal plate of the bulblets; a radial vascular bundle (RVB) different iated in the roots developing from the basal plate of the bulblets. Ma jor vascular bundles of the bulblet scale were connected to those of t he scale two nodes below; minor ones were connected to the vascular bu ndle of the scale one node below. Root primodia were formed from the r ing tissue at the basal plate of the bulblet. The regular system of va scular bundle was established in the regenerated bulblets cultured for 4 weeks on the medium without plant growth regulators, but it did not form on the medium containing 0.01mg.liter(-1) NAA and 2.0mg.liter(-1 ) BA. Many vascular bundle interlinkages are present in the central pa rr of the bulblets grown on the medium with 0.01mg.liter(-1) NAA and 2 .0mg.liter(-1) BA. Thus, a high concentration of benzyladenine (BA) re sults in irregular Vascular bundle system in regenerated bulblets.