Studies on Tetraploid Induction of Garlic Bud by Colchicine Injection

In order to acquire tetraploid garlic(Allium sativum L.),diploid garlic buds were injected with 0.05%,0.10%,0.15% and 0.20% colchicine,respectively.Then the aerial bulbils in garlic buds were cultured in MS medium combined by different growth regulators.After a regeneration system was constructed,polyploid appraisal was conducted on the root tip.The result indicated that more aerial bulbils were able to germinate on the MS basic culture medium adding 0.05 mg·L-1 NAA and 2.0 mg·L-1 KT.The aerial bulbils with 4-5 mm diameter had the highest germination rate.The germination rate of‘ Cangshancaosuan' bulbils was higher than that of‘ Jinsuan No.3'.When the garlic buds were injected with colchicines,the mortality of‘ Jinsuan No.3' bud was much higher than that of‘ Cangshancaosuan'.The number and size of the formed aerial bulbils were decreased and the rate of doubled chromosome was increased along with the increase of colchicine concentration.The highest doubling rate of‘ Cangshancaosuan' was obtained by the treatment of injecting the buds with colchicine concentration at 0.20%,and its induction rate was 7.69%.The highest doubling rate of‘ Jinsuan No.3' was obtained by injecting the buds with colchicine concentration at 0.15%,then its induction rate could reach the highest-11.76%.