Reduction of vitrification in in vitro raised shoots of Chlorophytum borivilianum Sant. & Fernand., a rare potent medicinal herb.

ABSTRACT

Reduction of vitrification in in vitro raised shoots derived from shoot bases and immature floral buds along with inflorescence axis used as explants of C. borivilianum, a rare medicinal herb is described. Shoot multiplication was obtained on MS medium with 2 mg l(-1) benzylaminopurine (BAP) + 0.1 mg l(-1) indole-3-butyric acid (IBA) and MS medium with 2 mg l(-1) kinetin (Kin) + 0.1 mg l(-1) 2,4-dichlorophenoxy acetic acid (2,4-D) from shoot bases and inflorescence axis respectively. Best multiplication rates were obtained from both the explants on MS medium with 2 mg l(-1) BAP. Vitrification of shoots in cultures appeared during the multiplication stage. Culture bottles with aerated caps reduced the vitrification to 80%. Reduction of BAP concentration from 2 mg l(-1) to zero during subsequent subcultures also minimized vitrification. Use of 0.5-2 mg l(-1) Kin produced healthy shoots when compared to BAP. In vitro raised shoots rooted on Knop salts containing iron and vitamins of MS medium, 2 mg l(-1) IBA and 0.1% activated charcoal. About 80% plantlets survived upon soil transfer. Scanning electron microscopic and image analyzer studies reveal the morphological structural differences between the leaves of normal and vitrified plantlets.