Effect of Several Kinds of Extracts from Plant on the Content of Nucleic Acid and Flavonoid in the Tobacco Leaf Infested by TMV

[Objective] The theoretical basis of the preparation of the plant type of bio-agrochemical agent resisting tobacco mosaic virus(TMV) was provided through the research on the inhibition and controlling effect of several extracts from the plant on TMV.[Method] The tobacco——K326,infected by TMV through the conventional mechanical method,was sprayed with the bio-agrochemical agents prepared made of the extract from 20 species of plants such as Hedyotis diffusa and so on.The content of nucleic acid and flavonoid was tested in the tobacco leaf on the 5th,10th,15th and 20th day after its being infested and the inhibition role of the extract to TMV was analyzed.[Result] The content of DNA in plant after its being treated was increased compared with the CK,which indicated the normal synthesis of the cell was recovered.The content of RNA was decreased compared with the CK,which indicated the content of TMV in plant was decreased and the treatment could promote the function of plant cell being normal again.The content of flavonoid was also increased after treatment.[Conclusion] The treatment of bio-agrochemical agent resisting TMV could inhibit the copy of it in tobacco plant.