Effects of sugar concentration and strength of basal medium on conversion of somatic embryos in Asparagus officinalis L.

The effects of sugar concentration and strength of basal medium were studied to produce plants from somatic embryos in Asparagus officinalis L. There was a significant difference among concentrations of sugar but not among kinds of sugar tested in the present experiment in growth of shoots and roots. When the sucrose concentrations were 10, 30, or 50 g l ˇ1 , the fresh weight of shoots were 31.5, 14.9, or 8.6 mg per plant and the fresh weight of roots were 14.5, 33.7, or 46.3 mg per plant, respectively. There was a significant difference among strength of basal medium in shoot growth but not in root growth. When somatic embryos were cultured in a half, full, or twice the strength of basal medium, the fresh weight of shoots were 8.9, 31.0, or 60.0 mg per plant, respectively. The effects of sugar concentration and strength of basal medium were also studied in the postculture process of somatic embryos to produce encapsulatable units, and in the conversion process of them. Not only the sugar concentration in the conversion medium but also the concentration in the post-culture medium had significant effects on growth of shoots and roots. No significant difference was observed among strength of basal medium in the post-culture process. # 2000 Elsevier Science B.V. All rights reserved.