In vitro growth reduction of tomato and carnation microplants

Shoots which proliferated from shoot tip explants of Colorado White Simm carnation and Fantastic tomato on MS medium containing 5 mgl^-1 benzyladenine were rooted and grown in vitro as microplants. Tomato microplants grown in medium with 5 gl^-1 sucrose had less overall shoot and root growth than those with 10,20, or 30 gl^-1 sucrose regardless of NAA level. Carnation shoot growth was reduced by 5 g l^-1 sucrose but root growth was not affected except when no sucrose was supplied. Microplant height and rooting of carnation were maximal when grown in 20 gl^-1 sucrose whereas tomato microplant growth was greatest with 30 gl^-1 sucrose. Microplants of both species had reduced height and root growth when the MS nutrient salts were lowered to 25%, 50%, or 75% compared to full strength when sucrose was supplied at 5 gl^-1.