OPTIMIZATION OF THE HAIRY ROOT INDUCTION BY Agrobacterium rhizogene IN PEANUT(Arachis hypogaea L.)

In order to set up peanut genetic transformation system for the production of resveratrol from hairy roots of peanut,different parts of sterile seedling of peanut were infected with Agrobacterium rhizogene GIM1.141 to induce hairy roots.Four factors including addition of Acetosyringone(AS) in bacterium suspension,different explants,soaking period of bacterium suspension and hairy root-inducing medium were investigated.The hairy roots could be observed at each type of explants(leaflet,cotyledon and hypocotyl).Leaflet explant produced the high proportion of hairy roots followed by cotyledon and hypocotyl.Suitable soaking period of bacterium suspension for 10min or adding 100μmol/L AS increased the rate of hair roots induction significantly.The highest rate of hairy roots induction from leaf,cotyledon and hypocotyls was 87.29%,75.8%,23.33%,respectively.So hairy roots of leaflet and cotyledon induced by Agrobacterium rhizogenes with 100μmol/L AS for 10min were the optimum methods.After eliminating bacteria with cefotaxime,hairy roots could grow independently on MSB5 medium without auxin.