POLYPLOIDY INDUCTION OF MUTATION BY USING COLCHICINE ON TUBE SEEDLINGS OF VICTORIA GRAPE

Stem segments of the tissue culture-grown seedlings of the Victoria grape were soaked 24 or 48 h using an aqueous solution of colchicine (0.05% or 0.1%). The best treatment for chromosome duplication efficiency was the use of the third and fourth buds treated for 48 h in 0.05% colchicine or 24 h in 0.1% colchicine. The doubling rates of primary generation cells were 33% and 31%, respectively. The polyploid cell percentage increases about 10% by subculture of the chimeras. The polyploid cell percentage could reach 75.8%-96.6% by subculturing the chimeras for four to six generations. Through root tip cell chromosome observations, there was little effect on the division cycle of root-tip cells in terms of the cultured seedlings with or without illumination in the short term, and the optimal sampling time of root tips for chromo-some observation was at 9:30 am.