OBSERVATIONS ON THE “TEST-TUBE” PLANTLETS REGENERATED FORM CAllUS OF DIFFERENT EXPLANTS OF DAYLILY (HEMEEROCALLIS CITRINA BAR.)

Studies on the formation of globulas from different explants and plantlet regeneration of daylily (Hemeerocallis citrina Bar.) were carried out. The results indicated that the sequence of the frequency of callus induction, from high to low, was flower stalk, flower stem and leaf blade. Delicate granular calli were observed on MS with 2.0mg/L 6-BA medium. and globulas formed progressively through the procedure of reproduotion-cutting-reproduction. Through 20 passages subculture of the globulas from leaf blade and flower stem explants, the regenerating ability kept stable, the morphology of plantlets were normal and the chromosome number of root apex cell was 2n=2x=22. Many morphological types of tetraploid "test-tube" plantlets (2n=2x=44) were obtained and a few repeated-double plantlets (2n=2x=88) were observed after the globulas treated by colchicine. And the globulas of wide-leaf tetraploid plantlet regenerated by oriented select were subcultured, we obtained the some plantlet. In the plantlets from globulas of flower stalk, we found some abnormal ones whose leaves look like petal or flower. It was suggusted that they were abnormal flower organ The plantlets regenerated from globula or globula newly formed from the leaf of abnormal plantlet were still abnormal, and good relationship between the frequency of the globula formation and flowering period or size of explant were also observed. Many types of chromosome number of varied plants were obtained from the globulas of flower stalk treated by colchicine. Finally we suggested that flower stalk isn't suitable as explant during the rapid propagation of daylily.