Inducement Of Hairy Roots And Establishment Of Culture System In Tea Plant

In ordering to establish genetic transformation system of tea plant induced by Agrobacterium rhizogenes, the Agrobacterium rhizogenes transforming to tube-shoots and selecting from roots naturally infected by wild Agrobacterium rhizogenes in tea plantation and the hairy roots induced and cultured were studied.Agrobacterium rhizogenes strains 1000, 1025, 1601, 9402, 15834 were employed to induce hairy roots from different explants of different varieties of tea plant for Dahong, Anhuayuanye, Donghuzao. Hairy root only was successful attained from stem explants of Dahong, which with little leaf infected with Agrobacterium rhizogenes strain 1025, after culturing on 1/2MS medium for 50 days.Hairy roots only induced from root callus of Anhuayuanye, Longjing 43 cultured in field. Callus can be induced from roots of five varieties of tea plant Wuniuzao, Longjing 43, Anhuayuanye, Zhuyeqi and Pingyun which cultured on MS medium containing 1 mg/L BA and 3 mg/L IBA, the inducement frequency of callus from different varieties shows obvious difference. No adding BA to medium, the time of callus induced from roots of Tea plant would be shorted.Natural hairy roots and artificially infection hairy roots show similar growth characteristics. Hairy roots grow well on medium at pH 4.5-5.5, inhibitory effect to the growth of hairy roots on medium at pH above 6.0.The growth of hairy roots cultured on amend 1/2MS medium is better than that on MS, B₅, White mediums. Hairy roots have lateral branches of roots but grow slowly on ammonium nitrogen-free medium. Addition of IBA 0.1mg/L and Al(NO₃)₃ 0.1mmg/L to the medium significantly promoted the growth and differentiation of hairy roots. Hairy roots become thicken and develop callus on medium with 3% sucrose.Hairy roots were cultured on amend 1/2 MS for 8 days will be in fast growth period, and which cultured for 20 days will increased for 8 times.Hairy roots exhibit active elongation with high branching of roots and extend rapidly after sub-culturing for long time, however normal roots shows not extend, and seldom-lateral branch. These characteristics can be regarded as the preliminary basis of selecting hairy root.