Walnut Tissue Culture Of Stem Segments And Its Impact Factor

Study on Factors Affecting Tissue Culture of Axi I lary Shoots of Seedling Walnut Postgraduate:Tian Ai mei Supervisor: Wu guo hang ABSTRACT Axillary shoots were collected from young and matural walnut trees. A series of factors affecting tissue culture of walnut were studied. The experiment shows: Contamination rate was different when explants were collected in different time. So the optimal time of collecting explant was the middle of May to the middle of June for young trees, contamination rate was 3.2%. and the late of April to the early of June for mature trees was suitable,contamination rate was 6.0% Axillary. In this experiment, two tioxidants and two adsorbents which can prevent explants of walnut trees from browning were investigated. The result showed that 5mg/i vitamin C can prevent explant from browning efficiently,only 8.6% shoot were browned. Shoots were deduced with modified DKW medium. By studying effect of different cytokin and auxin on gowth of explant,some conclusions were drawed: Axillary shoots were induced with modified DKW medium + BA1 .0 + IBAO. 1 + Vc5.0 for young trees and modified DKW medium + BA1 .0 + IBAO.0l + Vc5.0 for mature trees. The formation of adventitious multiple shoots was observed in the subculture of young walnut with modified DKW medium + BA1 .0 + IBAO.0 1 .The efficiency of shoot multiplication rate was 500% in one month.For maltural trees, modified DKW+BA1.0 + IBAO.00l was suitable.Rooting was induced on 1/2 modified DKW + IBA5.0 + VcO. 1 in darkness for 7 days,then shoots were transferred to 1/2 modified DKW medium supplemented with AC 2gtL .Culturing in darking and deducing mineral composition can improve rooting rate,53.5% shoots rooted.