Effect of Hormones on Callus Status of Ginkgo Biloba Leaves and Establishment of Suspension Culture System
By using Ginkgo Biloba leaves as materials,the effects of different combinations and proportions of auxin(NAA,2,4-D),cytokinin(6-Ba,KT)and different culture media on callus state were studied so as to screen out the best combination of hormones and culture media suitable for callus induction of Gink-go Biloba leaves.Excellent suspension cell culture system of Ginkgo Biloba was established after the sub-culture of fine callus.The results showed that the callus induction rate of NAA and 6-BA combination,NAA and KT combination was higher than that of 2,4-D and 6-BA combination,2,4-D and KT combina-tion.And the induced callus state was better.The browning degree of callus induced by different hormone combinations was different.The callus induced by NAA and 6-BA combination,NAA and KT combination had no browning,and the browning degree of 2,4-D and 6-BAcombination,2,4-D and KT combination was more serious.When NAA and KT was combined,NAA concentration was 1.5 mg/L and KT concen-tration was 1.0~1.5 mg/L,the induction rate of callus was high and the callus state was excellent.When NAA and 6-BA was combined,and NAA concentration was 1.5 mg/L and 6-BA concentration was 0.5~1.0 mg/L,the callus induction rate was high.The suitable culture medium for inducing Ginkgo Biloba leaves callus were N6 and MS.In conclusion,the suitable combinations of hormones for inducing Ginkgo Biloba callus are NAA and KT,NAA and 6-BA.Excellent callus(loose,granular,yellow-green,no brown-ing,no water stain)can be induced by the combinations on N6 or MS culture medium.After subculture,the suspension cell culture system of Ginkgo Biloba can be established.