IN VITRO PROPAGATION AND FIELD TEST OF TARO VIRUS-FREE PLANTLETS

The virus-eliminating technology ( Colocasia esculenta Schott) with shoot-tip culture and rapid propagation of taro were studied. Two methods, i.e., the SPA-ELISA and the electron microscope, were used for virus detection of the plantlets. The results indicated that the plantlets did not carry dasheen mosaic virus with exfoliating shoot-tip ( smaller than 0.6 mm) culture by three times . The best medium for bud propagation was MS +ρ(BA)1.0 mg L -1+ρ (NAA)0.2 mg L -1, and monthly propagation index was 5.6. The rooting and new seedling differentiation were simultaneous when the shoots were cultured on MS medium supplemented with 0.05～0.1 mg L -1NAA and 0.15 mg L -1 BA. The seedlings were growing luxuriantly after virus-free plantlets were planted in the net-room, and averagely 29.1 cormels came out from each plant. Plot test showed that the amount and yield of cormels of virus-free taro were increased by 37.6%～62.6% and 20.2%～40.0%, respectively, and the amount of commodity cormels was increased by 44.1%～67.6%. Tab 4, Ref 11