Foliar Emergence from Bulblets of Lilium longiflorum Thunb. as Related to in Vitro Generation Temperatures1

Self Cite

Bulblets from bulb-scale explants of Lilium longiflorum Thunb. cvs. Ace and Nellie White cultured in darkness on a semisolid Linsmaier-Skoog medium supplemented with 0.03 mg/liter α-naphthalene-acetic acid (NAA) bore no leaves when produced in vitro at constant 30°C but often did when produced at constant 25°. In vitro temperature regimes involving both 25 and 30° resulted in the largest number of leaves per explant. Time in vitro in each temperature regime was calculated to provide equal heat units so that differences could not be explained by a linear relationship between development and temperature × time. Physiological state of explants, measured by time lily bulbs were stored at 4° before tissue culture, interacted with in vitro temperature. Explants from bulbs stored 110 days or less produced significantly fewer but significantly larger bulblets at constant 25° as compared to constant 30°. This difference was not apparent when explants were taken from bulbs stored at 4° more than 110 days. In an experiment with explants from bulbs stored 80 days, there was no significant difference between ‘Ace’ and ‘Nellie White’ in number of scales per bulblet at either 25 or 30° but bulblets of both cultivars contained significantly fewer scales if generated at 30°. Mean width of meristems in ‘Ace’ bulblets was significantly greater when produced in vitro at 30°. Neither initiation of bulblets nor bulblet development appeared controlled by apical dominance.

Section: Weight (Mg) Per Bulbietmentioning

confidence: 99%

Developmental Responses of Lilium longiflorum Bulblets to Constant or Alternating Temperatures in Vitro1

Stimart

Ascher

1981

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“…In spite of the ease of transplanting, a problem encountered in the cultivation of bulbs in soil was the dormancy induced during regeneration and growth in vitro. Though Stimart and Ascher (6,7) reported that temperature or irradiation during in vitro cultivation affect dormancy, sucrose concentra-Fig. 5.…”

Section: Discussionmentioning

confidence: 99%

“…Transplanting and growth of bulbs in soil of Lilium produced in vitro has been reported by Novak and Petru (4) and by Stimart and Ascher (6), but problems of bud emergence were not described. Recently, Stimart and Ascher (7) indicated that bulblets of L. longiflorum generated in vitro at 30°C produced leaves more rapidly and more completely after transplanting to vermiculite than those generated in vitro at 25°. We planted over 30,000 L. speciosum and L. auratum in vitro-produced bulbs in the field after treatment at 5° for 55 days, but only 15% of those bulbs produced emergent leaves.…”

mentioning

confidence: 99%

Cultivation of in Vitro-propagated Lilium Bulbs in Soil1

Takayama

Misawa

Takashige

et al. 1982

The transplanting to soil of bulblets of Lilium longiflorum Thunb., L. × formolongi, L. speciosum Thunb., and L. auratum Lindl., grown on Murashige and Skoog’s medium, was investigated in relation to dormancy. Leaf emergence from tissue-cultured bulblets was inhibited after transplanting into soil without low-temperature treatment. To break dormancy, low temperature (5°C) treatment for 70 days was required when bulblets were produced in the medium with 30 g/liter sucrose, while 120 to 140 days were required when bulblets were produced in the medium with 90 g/liter sucrose. In vitro-produced bulblets of L. longiflorum grew well in soil and about 40% of the bulblets flowered in a year.

“…If plantlets produced in a lighted environment were transferred to vermiculite and placed under a 16-hr Cool-White fluorescence/8-hr dark cycle at 25°, they continued to produce leaves. Bulblets generated in vitro in the dark at 25° or 30° started to produce leaves 2 to 3 weeks after transplanting to vermiculite (17). However after 14 weeks, 90% of the bulblets produced in the dark at 30° developed foliage, while only 22% of the bulblets generated at 25° in the dark bore leaves.…”

mentioning

confidence: 98%

Overcoming Dormancy in Lilium longiflorum Bulblets Produced in Tissue Culture1

Stimart

Ascher

Wilkins

1982

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Leaf emergence from bulblets of Lilium longiflorum Thunb. generated in vitro from bulb-scale explants incubated in the dark at either 25 or 30°C was enhanced by 3 stimuli: incubation at 4°C for 1 or more weeks after removal from culture; immersion in water at 45° for 30 minutes to 8 hours after removal from culture; or in vitro red-light irradiation. For maximum response, bulblets generated at 25° required longer treatments at either 45° or under red-light irradiation. On the other hand, bulblets generated in vitro at 30° responded least to incubation at 4°. Although all 3 environmental factors ended dormancy, variation in rates of leaf emergence and total percentage of bulblets with leaves at the end of the experiments suggested differences in the state of bulblet dormancy due to in vitro temperature and differences in the physiological action of the environmental stimuli promoting leaf emergence.