Benzyladenine and low temperature promote phase transition from juvenile to vegetative adult in bulblets of Lilium × formolongi ‘White Aga’ cultured in vitro

Abstract

Scales excised from lily bulblets were cultured on MS medium supplemented with 0.044 or 4.4 lM BA in the dark for 180 days. The culture period was divided into stage 1 (day 0-30), stage 2 (day 31-90) and stage 3 (day 91-180). The scales were cultured at 25°C in stage 1, 25°C or 8°C in stage 2, and 25°C in stage 3. When the scales were cultured on medium with 4.4 lM BA at 25°C for 180 days, bulblets with and without an elongated stem were produced. The percentage of bulblets with elongated stems greatly increased when the scales had been cultured at 8°C in stage 2. On medium with 0.044 lM BA, only bulblets without elongated stems were produced. The diameter of shoot primodia significantly enlarged in bulblets produced on medium with 4.4 lM BA at 8°C in stage 2 and no such enlargement occurred under the other conditions. Nearly square parenchyma cells were observed in the non-elongated shoot primodia in the former bulblets but not in the latter. These cells changed into longitudinally rectangular ones in the internode of elongated stems. Procambium was arranged almost parallel to the shoot axis in the stem of bulblets in the medium with 4.4 lM BA, but not in the medium with 0.044 lM BA.

Somatic embryogenesis and direct as well as indirect organogenesis inLilium pumilumDC. Fisch., an endangered ornamental and medicinal plant

“…One reasonable explanation is that BA plays a more effective role than NAA 29) by virtue of its critical action in cambium differentiation and bulblet development. 30,31) Unlike direct shoot organogenesis, a lower BA/NAA ratio was most suitable for OC induction from basal leaves of in vitro stock bulblet cultures and the optimal OC induction medium was MS with 1.0 mg L −1 BA and 0.5 mg L −1 NAA, i.e., at a BA/NAA ratio of 2 in the process of indirect organogenesis. Similarly, OC was successfully obtained from leaves and scales of L. leucanthum using 0.5 mg L −1 BA and 1.0-3.0 mg L −1 2,4-dichlorophenoxyacetic acid (2,4-D, an auxin), i.e., at a lower cytokinin/auxin ratio.…”

Endogenous cytokinin dynamics in micropropagated tulips during bulb formation process influenced by TDZ and iP pretreatment

“…In accordance with these suggestions, and our findings, exogenous CK (BA) and low temperature also promote bulb primordia development in Lilium sp. cultured in vitro according to Ishimori et al (2007).…”

Factors Affecting Bulblet Growth of Lilium sp. - Tracking Ontogenic Development and Bulb Production in vitro

“…6). Therefore, according to Boontjes et al (1981) and Langens-Gerrits et al (1996a), in lily, stem formation is stimulated in the bulblets when complete scales or scale segments are cultured at 17°C after initial culture at 23°C"indicates that the lower temperature acts as a trigger or signal, inducing the transition from the juvenile to adult vegetative phase (Ishimori et al 2007, Langens-Gerrits et al 2003b. Fig.…”