Establishment Of Liquid Culture Systems For Protocorm Like Bodies And Artificial Seeds Making Of Oncidium

Oncidium is one kind of perennial herbaceous plant belonging to Orchidaceae family,it is also a very popular flower all around the world. In the recent years, Oncidium havebeen introduced to China and rapidly developed. The products of pot and cut flowers ofOncidium have increased every year. Because of the low efficiency of Oncidiura seedlingproduction, the quantity of seedlings could not satisified for the market, the seedlingproduction have been one of the most important factors.The cutting and sowing were the conventional way for Oncidium propagation, italways results virus infection and influences the quality of flower products. Recent year,almost all of the Onciudium is propagated by in vitro adventitious shoot or protocorm likebodies induced from shoot tips or axillary buds of virus free plants. Compared withadventitious buds regeneration pathway, the pathway of PLBs regeneration has manyadvantages: higher propagation rate, obtaining more plantlet and structure integrity, andalso PLBs can be proliferated in liquid medium. Although there are several reportsconcerning PLBs induction of Oncidium, the proliferation and differentiation rate reportedare very low. Thus, in this study, the factors impacting the PLBs proliferation andgermination in liquid culture system were investigated and also artificial seeds making byPLBs encapsulation were conducted. The results are as follows.1. MS was the suitable basal medium for PLBs proliferation of Oncidium in liquid culture;At the concentration of 0.5 mg.L^-1 BA, the proliferation ratio can reach 2.52. The suitablepH was 5.4. Addition of coconut water and peptone promoted PLBs proliferation rate undera light intensity of 1000lâ…¹, addition of banana homegenate influenced the color of PLBs.2. 0.5 mg.L^-1 BA promoted germination of PLBs; desiccation treatment for 5 daysimproved the germination rate, the average number of shoots germinated were 37.65 pergram PLBs. 4000 lâ…¹light intensity promoted the germination rate.3. 1/2MS supplemented with 0.5mg·l^-1 NAA and 1.5% sucrose promoted rooting ofOncidium plantlets; the average number of roots each plantlet was 3.78, root length was21.1 mm.4. MS basal medium supplemented with 2% sodium alginate acid and 0.2 mg. L^-1 GA₃ wasthe optimal artificial endosperm, the suitable germination medium for artificial seeds was 1/2 MS containing 0.2 mg.L^-1GA₃, the germination rate was the 100%, but the BA inducedthe secondary PLBs.