Studies On Liriope Spicata (thunb.) Lour. In Cytology And Tissue Culture

Liriope spicata (Thunb.) Lour. is the original variety of Liriope spicata (Thunb.) Lour. var. prolifera Y.T.Ma, which is known as the main materia medica of traditional Chinese medicine, Maidong. L. spicata var. prolifera is a authentic materia medica in Hubei province. With the aim to cope with research of sterility of L. spicata var. prolifera, the present study was carried on L. spicata in genetics, cytology and tissue culture, hoping to acquire some novel findings between the two plants. The results are shown as follows:1. Karyotype of L. spicata was examined using the squash method and wall degradation hypotonic treatment (WDH) method. The results indicated that squash method was a better way for L. spicata's karyotype analysis and it is tetraploid. The karyotype formula, which belongs to symmetrical 2B type, is 2 n=4 x=72=48 m+24 sm.2. Meiotic behavior and pollen development of L. spicata were observed using the squash method and WDH method. Pollen viability and aberration rate were estimated. During the meiosis of microspore mother cells (MMC), most of the cells displayed normally, while some chromosome bridges, fragments and lagging ones were formed at anaphase(<5%). Pollen aberration rate was 3.44% in 1 106 cells.3. Anther and pollen development process of L. spicata were observed under microscope by means of paraffin section. The tapetum showed the characteristics of secretory tapetum which began to degrade during dyad stage. The tapetum and middle layer completely disappeared when pollens were fully mature at 3-celled stage. Tapetum played an important role in anther and pollen development.4. This study set up a new way for anther culture and intermediate propagation of L. spicata. Callus was induced from anther of L. spicata on a MS medium supplemented with different hormones. MS+ KT 2.0 mg/L+2,4-D 1.0 mg/L gave the highest induction ratio which was 30.77%. MS+ 6-BA 1.5~2.0 mg/L+ NAA 0.1~0.3 mg/L was suitable for the induction and proliferation of indefinite buds. The buds were transferred to 1/2 MS medium supplemented with NAA 0.1~0.3 mg/L for rooting. The shoots produced roots of culture and formed complete plantlets. The squash method combined with microscope was used to analysis chromosomes of regenerated plantlets.