DOMINANT EXPRESSION OF VIGOR AND HEAT TOLERANCE OF LILIUM LONGIFLORUM GERMPLASM IN DISTANT HYBRIDIZATION WITH ASIATIC AND ORIENTAL LILIES

Distant hybridization between Lilium longiflorum and Asiatic or Oriental lilies was accomplished by in vitro pollination and ovary culture, or by in vivo pollination combined with ovary-slice culture. L. longiflorum was preferred as the maternal parent.
More than 15 combinations were successfully rescued and multiplied by micropropagation or by scaling.
Hybridity was confirmed by isozyme and cytological markers. In vitro plantlets of five distant hybrids were potted and tested under controlled temperature conditions.
Most of the distant hybrid clones exhibited high to medium vigor.
They developed shoots and bloomed within 8–10 months under temperature regimes of 13–35°C. The formation and unfolding of scale leaves were accelerated by higher temperatures.
Phase change from rosette to shoot stage occurred under temperatures of 15/13°C. It was also induced by 6 weeks of natural winter cooling under subtropical climatic conditions.
Floral bud development and anthesis in three of the clones were heat tolerant.
In the current cycle, distant hybrids produced bulbs in size ranges of 12.7–16.4 cm and 10.8–13.9 cm under conditions of 20/15°C and 35/10°C respectively.
Additionally, the out-facing, funnel flower pattern of the longiflorum group was expressed as recessive or intermediate to the up-facing, split perianth type.
The strong expression of rosette growth and heat tolerance indicates that breeding between distant types might facilitate the development of lines suitable for cut flower and bulb production in one cycle, as well as, being adapted to subtropical conditions.

VII International Symposium on Flowerbulbs

S.W. Chin, C.E. Kuo, J.J. Liou, C.T. Shii

https://doi.org/10.17660/ActaHortic.1997.430.79