Research On Micro-environmental Of Micro-propagation And Environmental Control Facilities For Large-scale Plant Tissue Culture

Plant tissue culture is a widely used biological technique method for production of large number of genetically identical plantlets. It has many advanages over conventional propagation techniques, and has been developed to an important plantlet propagation way. Plantlets obtained from plant tissue culture will widely applied to hoticulture, crop and forestry. However, the conventional method and facilities for plant tissue culture have severly limited commercial micro-propagation production and its large-scale application.Engineering techniques having been applied to the micro-propagation. This will be helpful in attempting to take advantage of the benefits of micro-propagation over conventional propagation techniques, such as: rapid clonal propagation; decreasing diseases of plantlets and the period of acclimatization ex vitro; cutting down motherstock requirements; improving the survival of micro-propagation plantlets after transfer to ex vitro conditions, etc., and then reducing the cost of micro-propagation plantlets. Development and application of both automated environmental control system and suitable industrial-scale culture facilities are essential for its commercial application in agriculture.In this paper, environmental factors of micro-ecology in vitro and their effects on the growth of plantlets in vitro were summarized, and the developments of environmental control technology and culture facilities were envaluated. And then, some basic and original researches have been done. The paper focused attention on the research of micro-ecology in vitro, and tried to apply some new research approaches and thoughts to the study work. These work include: to evaluate the electrical lights for plant tissue culture and give the optimization of lamps; to probe the heat balance ofmicro-environment and give the measure of decrease in temperature; to determine the hourly ventilation rate of closure materials and probe their influce in factors of micro-environment; to study the effects of different compensatory of the photosynthetic photo flux density (PPFD, symboled by the variable I) and the CO2 concentration (symboled by the variable C0) on the photosynthetic rate of plantlets (symboled by the variable Pn), and then constructe the photosynthetic model, that is the function Pn^{C0, I}; to researche the effects of relative humidity on the plantlets in vitro, etc. . On the whole, main studies work and results can be introduced in detail by the following seven topics:1 N Study was designed on the electrical lights for plant, the relative energy spectrum distributions and illuminance of four electrical lights, such as the dysprosium lamp for greenhouse and the daylight fluorescence lamps in plant tissue culture works and the plant fluorescence lamp etc., were determined; the ratio and efficiency of the effective photosynthetic radiance of the four electrical lights were caculated, analysed and evaluated; the illuminance was analysed and evaluated; the optimization electrical light for plant tissue culture, that is lanthanon fluorescence lamp, was firstly given; and for the first time, the principles for development of electrical lights for plant tissue works were proposed as the followings: (1) the shape of lamp should be tube; (2) the ratio of energy in red-orange spectrum to that in blue-purple spectrum should be over 0.9; (3) the power of lamp should be under 100W; (4) the efficiency of lamp should be more than 50 Lm/W.2% Research was undertaken on the effects of lamps on the heat balance of micro-environment, and then, three measures for decrease in temperature were proposed as followings: (1) to reduce the temperature of tube and its attachments; (2) to intercept the heat flux between lamps and culture box; (3) to decrease the amount of infrared lights running into the box. Upon these studies, a device for control of lights density and temperature in micro-environment was designed and constructed. By using the device, the temperature can be kept on 25"C²7癈, and the light density can be control at will...