Leave source from callus induction and flavonoid content in callus from different tissues of five Ginkgo biloba cultivars

The objectives of this study with Ginkgo biloba were to establish a callus culture system for leaf sources and to determine the flavonoid content in callus from different gingko tissues.Five elite cultivars(Number 44,45,28,79 and 53) with mediums of N6,MS(Murashige Skoog medium),improved MS and DCR(Douglas-fir cotyledon revised medium),and growth supplements of NAA(naphthalene acetic acid),6-BA(6-benzylaminopurine),and KT(kinetin)were tested with roots,leaves,cotyledons,and stems as cultured explants.The induction rate,growth,and flavonoid content in the callus from different cultivars and explants were canpared.Results indicated that a supplement of 0.10.5 mg·L-1 of NAA and 0.5-1.0 mg·L-1 of 6-BA in the medium favored leaf size(P0.01).The induction rates of leaf callus in cultivars '28' and '79' were significantly higher(P 0.01) than the other cultivars.Medium N6 was better for inducing callus than MS,but N6 was not better for a subculture.The 6-BA supplement in a medium more readily(P0.01)induced callus than KT.Also,the flavonoid content in the callus of cultivars '28' and '79' was higher(P0.01)than the other cultivars. For all cultivars,flavonoid content in the callus from different explants was root leaf cotyledon stem.[Ch,2 fig.4 tab.18 ref.]