LUO Jianpiao;TAN Jiana;GUAN Jinyan;HUANG Haiying;CHEN Yuegui;YANG Junxian;LUO Qingwen;Guangdong Key Lab of Sugarcane Improvement and Bio-Refinery,Guangdong Bioengineering Institute;Zhanjiang Sugarcane Research Center,Guangdong Bioengineering Institute;

Anoectochilus;;Anoectochilus roxburghii;;Ammonium nitrogen;;Nitrate nitrogen;;Tissue culture

In order to analyze the influence of different combination ratios of ammonium nitrogen and nitrate nitrogen on the tissue culture plantlets of Anoectochilus roxburghii and Anoectochilus plant from Yunnan, nine concentration gradients of NH_4~+/NO_3~- were set:0/30,5/25,10/20,15/15,20/10,25/5,30/0,20/40,30/30. Terminal buds and stem segments of the two plants' plantlets were inoculated in the medium and various growth indexes were measured after 90 and 120 days so as to provide references for the tissue culture,rapid propagation, and reasonable application of nitrogen fertilizer.The results showed that different combination ratios of NH_4~+/NO_3~- not only had significant or extremely significant impacts on the terminal buds reflecting in height, internode number, dead number of internodes, leave number,dead number of leaves,length and width of the first leaf near the stem apex,number and length of the roots in the medium and in the air,but also had significant or extremely significant impacts on the stem segments reflecting in budding number, height of buds, internode number, leave number, length and width of the second leaf above,stem diameter,root number of the buds.At the total nitrogen concentration of 30 mmol/L,when the combination ratios of NH_4~+/NO_3~- were relatively low, terminal buds of the two plants grew well, stem and leaves appeared normal, the budding rate of stem segments was high and the new buds grew well; while with the increasing combination ratio of NH_4~+/NO_3~-, terminal buds of the two plants grew worse and worse, the budding rate of stem segments became lower and lower and the new buds grew weaker and weaker.High combination ratios of NH_4~+/NO_3~- led to the death of the terminal buds and stem segments at last.The combination ratios of NH_4~+/NO_3~- had important effects on the plant morphology of Anoectochilus.The better combination ratios of NH_4~+/NO_3~- for the growing of Anoectochilus roxburghii's terminal buds and for the shooting of its stem segments were 0/30,5/25,10/20,20/40,while the better combination ratios of NH_4~+/NO_3~- for Anoectochilus plant from Yunnan were 0/30,5/25.In the process of tissue culture,organic and inorganic nutrients can be added into the medium based on these better NH_4~+/NO_3~- ratios to promote the growth of seedings;nitrate nitrogen ratios can be raised under field conditions.