摘要 : The effects of plant growth regulators on the growth of shoot tip cultures of 6 variegated and 6 non-variegated Hosta cultivars were investigated. Shoot tips were cultured on Murashige and Skoog (MS) medium supplemented with sucro... 展开 The effects of plant growth regulators on the growth of shoot tip cultures of 6 variegated and 6 non-variegated Hosta cultivars were investigated. Shoot tips were cultured on Murashige and Skoog (MS) medium supplemented with sucrose (30 g/litre) andplant growth regulators. Axillary shoot multiplication was stimulated by the addition of NAA (0.01 or 0.10 mg/litre) to a medium supplemented with 6-benzylaminopurine [benzyladenine] (BA; 3 mg/litre). IAA and IBA did not promote axillary and/or adventitious shoot formation compared with NAA. BA stimulated a higher number of axillary shoots than 2iP [isopentenyladenine] or kinetin. Axillary and adventitious shoot multiplication were best at 25℃ with photosynthetically active radiation of 70-80mol m-2s-1. Rooting of shoots in vitro was observed on MS medium without growth regulators or supplemented with NAA at 0.01 mg/litre. Rate of shoot multiplication depended on genotype and chimaeral or non-chimaeral characteristics. Regenerants were successfully established in soil. Some plants obtained from culture which had lost leaf variegation regained it after 1 year in the field. Frequencies of plants exhibiting somaclonal variation were in the range 1.8 to 43.8%. Most genetic variants showed differencesin leaf area, chlorophyll content and petiole length compared with parent plants. It was concluded that successful micropropagation of Hosta could be achieved from shoot tips which produced axillary shoot cultures without a callus intermediate step. 收起