Studies On The Prevention And Cure For The Contamination Of Plant Tissue Culture

Studies on the contamination of plant tissue culture was studied in Shandong Agricultural University and Tai'an Agricultural Science and Technology Company during 2000-2002,using some kinds of fruit trees (P sernlata Ledeb; C erasiis vulgavis MilL Fradaria vesca L^ Ziziphus jujube mill; Z saliva Gaevtn^ Punica granat um L.),flowes (Rosa rugosa^ Euphorbia pulcherrima^ R.multiflora) and forest trees (Balizhuang-yang^ Populus L. -. Broussonetiapapyrifera L.) as materials. The main results were as follows:1. According to colony character of the microbe, taking photographs by electron microscope, shape character, habit and characteristics of live of insect , the identification is made. As is thought that contamination was caused mainly by fungus (Fusarium > Aspergillus niger^ Penicillium ).bacterium(G^ and G~ ) and insect (acarus and thrips ).2. Under the condition of plant tissue culture, having the diameter of fungus community as guide line, the propagation and growth of different fungus is measured. Status of propagation and growth of bacterial is measured by spectrophotometer. From the growth status of fungus and bacteria, a rapid growth phase could be seen in both of them.3. The distributing of fungoid both explant and culture bottle was investigated in system, the result of the experiment showed that there was some difference in the distributing of fungoid between every part of explant, and there was less fungoid in the newly born leaves and buds; The wall of the culture bottle and the seal paper could also carry fungoid which brought about contamination of plant tissue culture, and both of them became one of the fountainhead of contamination.4. The fungoid on the culture room and inoculation room was extinguished by using two kinds of method including ultraviolet radiation and ozonizer. As was thought that it was better to extinguish the fungoid using ozonizer than ultraviolet radiation, the effect of ozonizer was better and it could thoroughly extinguish the fungoid without leaving any dead angle.5. When the diameter of the plant trachea was 100 times bigger than that of bacteria,the experiment showed that bacterial could thoroughly enter into the inside of the explant from the outside of the explant and turned into the endogenesis fungus, then that caused the contamination of the plantlet after the inoculation.6. Four steps was summed up on the prevention and cure about the contamination of plant tissue culture: First, the material used as inoculation should be collected in spring and autumn when the propagation of fungoid was slow; sprouting inside the room by collecting rigid branch outside the room in winter, then inoculating with young buds; avoiding as possible inoculation in summer, and spraying a certain concentration antiseptic medicine before collecting the material from the female parent. Second, check-up of the plantlet should be made frequently, and the contaminated medium should be excavated and the explant uncontaminated should be transferred in time. Third, integration of prevention and cure could be made by adding antibiotic and antiseptic used in medicine; Fourth, the plantlet having been contaminated could be saved by rooting in filter-paper bridge outside the bottle.