ISHS Acta Horticulturae 766: XXVII International Horticultural Congress - IHC2006: International Symposium on Ornamentals, Now!
A FORCING PROGRAM FOR PRECOCIOUS LA HYBRID LILIES |
| Authors: | H.T. Chen, C.E. Kuo, C.T. Shii, S.W. Chin |
| Keywords: | interspecific hybrid lily, precocity, rosette plant, forcing, bulb production, in vitro plants |
| Abstract:
This paper describes a forcing program for several micropropagated precocious clones of L. longiflorum x L. × elegans hybrid (LA) lily. The leaf unfolding rate of tested LA clones was measured as 0.5 - 0.7 leaves wk-1 under 30/25°C / 20/15°C (D/N) temperature regimes. The set of 10 rosette leaves served as a maturity index forcible to produce 1 - 2 flowers. The rosette leaf number (x) is closely related to flower number (y) calculated as y = 0.6x - 4.66, r2 = 0.77. The phase change from compressed shoot to elongating shoot is cold-sensitive, the rosette plants were exposed to a phytotron 15/13°C condition for 6-8 weeks (7000 - 9400 ctu) saturated for induction of shoot emergence. The establishment of the first elongation zone (node) was initiated at the cross interface between scaling leaf and young leaf characterized with synchronized transverse cell division. The second phasic change, from vegetative shoot to reproductive apex, occurs in about 27 days after precooling. The long day treatment did not totally substitute for cold requirement, but was able to compensate for two week precooling. The timetable for shoot emergence, visible flower buds and flowering of the precooled plants varied in the range 80 - 110 days, dependent on clones, growth temperature and daylength. The period of the current growth cycle is required in less than 10 months. The scale leaf number (x) of rosette stage is also pronouncedly correlated with mature bulb circumference (cm) calculated as y = 0.53x + 6.51, r2 = 0.88. It is concluded that the precocious LA lily are potential to produce cut flower and mature bulb in less than a year. | |
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