The Biocontrol Activity Of AOS Used In Plants

The damages by pests and diseases are one of the main threatening factors of agricultural production,resistant varieties and chemical pesticides are given priority to control crop diseases,and other agricultural methods are as an auxiliary.But because of the wide use of chemical pesticides,pathogenic bacteria and pests have had multidrug resistance,happend variation,created new small variety or variation department,leaded to increasingly poor effect of pesticides,insectpest prevention and control faced enormous difficulties.The using doses of organic pesticides were improved that caused great damage to living environment and human health.Therefore,the ways to solve these problems has been one of the important efforts of the agricultural science and technology researchers within the scope of world.Elicitors as a new type of biopesticide,haven't bactericidal activity,don't cause any damages to the environment and human,and can stimulate the immune systems of plants to produce systemic acquired resistance.Our country has developed more in-depth study in this aspect,the oligosaccharide elicitors has been used in the agricultural production,the further researchs of induced mechanism are also in progress.Because oligosaccharide can be used as elicitors to induce plants cells resisting reaction,improving the activity of defensive enzyme,synthetizing phytoalexins,to resist the infection of external microorganism,and oligosaccharide of sodium alginate(AOS)which are made from seaweed are very cheap,so this paper is about the study of the biocontrol activity of AOS in the plants.On the one hand,simulate soybean cotyledons method to establish a kind of concise,sensitive method of detecting elicitors(AOS)activity in rice seeds,and the results show that:soak rice seeds for 15 h with AOS,and induce them for 24 h,then detect the ultraviolet absorption of phytoalexins(Oryzalexin C)in OD245,this method can be used for detecting the activity of AOS;On the other hand,studied the induced activity of AOS to rice leaves,mainly include the inducing activity of AOS to defensive enzymes in rice leaves:Phenylalanine deaminase(PAL),peroxidase(POD)and catalase(CAT),the results showed that the activity of the three defensive enzymes were improved after spraying AOS on the surface of rice leaves,so AOS can improve the activity of defensive enzymes of rice leaves,and resist the infection of rice blast.