Rapid clonal multiplication of three Lilium species cultured in vitro

1987 Fiscal Year Final Research Report Summary

• Project/Area Number: 61560029
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 園芸・造園学
• Research Institution: Niigata University
• Principal Investigator: NIIMI Yoshiji Faculty of Agriculture, Niigata University Associate Professor, 農学部, 助教授 (20018790)
• Project Period (FY): 1986 – 1987
• Keywords: L.rubellum / L.japonicum / L.nobilissimum / Leaf segment / 鱗片分割培養 / 子球培養 / 開花球

Research Abstract

The present study was made to establish a tissue culture method for rapid clonal multiplication of Lilium rubellum Baker, L. japonicum and L. nobilissimum. Murashige and Skoog's inorganic nutrient medium(1962)(MS-medium) supplemented with vitamins and growth regulators(NAA,BA or both) was used. The transplantation to soil of the in vitro propagated bulblets was also described.
(1) Segments of growing leaves of L. japonicum and L. nobilissimum as well as those of scales developed bulblets well. The optimum concentrations of growth regulators NAA and BA in culturing the leaf segments were different: 0.5mg/l NAA and 0.05mg/l BA stimulated the induction and development of bulblets in L. japonicum; and 1.0mg/l NAA and 0.05mg/l BA in L. nobilissimum. In addition, these explants were not contaminted, unlike scale segments. Thus, it can be concluded that the leaf segments were superior to those of scales for the propagation of bulblets.
(2) To improve the rate of bulblet regeneration in the leaf segment cultures of L. rubellum, they were precultured in liquid MS-medium for more than 24h and then cultured in MS-medium solidfied with agar. But, the preculturing was found to be ineffecitve for otaining an increased rate of regeneration. The same method was used in the scale segment cultures of three lily plants to perform the mass propagation, but it was ineffective as well. Although a few other methods were examined for increasing the number of bulblets, the establishment of general methods for this has been unsuccessful so for.
(3) When bulblets formed on the explants of leaves, scales and stems were isolated and recultured in a fresh medium, they developed rapidly. Therefore, to obtain larger bulblets in a short period, it is necessary to isolate the developing bulblets from the explants and to reculture them as soon as possible.
(4) The transplanting to soil of L. Japonicum and L. nobilissimum bulblets developed in vitro was investigated in relation to their dormancy. Leaf emergence from the bulblets was inhibited after transplanting into soil without previous low-temperature treatments. To break dormancy, low temperature treatment(4゜C) for at least more than 8 weeks was required in these bulblets. GAs treatment was also effective to break the dormancy of L. nobilissimum and resulted in reducing the periods necessary for the breaking of dormancy.