SHOOT APEX CULTURE OF LONGAN (DIMOCARPUS LONGAN LOUR.) TREES
龙眼的茎尖培养

Procedures were developed for the micropropagation of longan (Dimocarpus longanLour.) using lateral and terminal shoots from seedlings and graftings of 6-year-old treesgrown in reticular plot. Shoot apex culture was established in two steps: sterilized explantswere first cultured for 30 days, then the 2 mm long segments of shoot apexes from axillarybuds were taken and cultured on induction and multiplication media. Four indexes wereused to evaluate the growth of cultures, i.e. the death rate, induction rate, leaf number,and the fresh weight. Of the media and explants examined, the best culture establishmentwas obtained with shoot apexes cultured on MS medium supplemented with 0.3 mg L~-16-BA, 0.1 mg L~-1 IAA and 3% sugar. Optimum hormones for shoot apex multiplicationwere 0.1 -0.2 mg L~-1 6-BA, 0.1 -0.5 mg L~-1 KT and 0-0.3 mg L~-1 IAA, the multiplicationrate being 3.05 times. Treatment in liquid culture with 0.01 mg L~-1 6-BA and 1.0 mg L~-1IBA in combination was best for rooting, the rooting percentage reaching to 34.1%.