The Research Of Soybean Root Rot Identification And Prevention In Xinjiang

Through investigated in the field and researched indoors for 3 years, discovered that the Fusarium,Rhizoctonia,Pythium and Phtophthora cause soybean root rot. Among them,the frequency of Fusarium isolated from soybean was high, and the pathogenicity of Pythium and Phtophthora was stronger than others.Because the Phtophthora sojae was the first report in xinjiang and it is regarded as a quarantine object in domestic and overseas , this discourse was researched chiefly the Phtophthora sojae and Pythium .By studied the biology traits of Phtophthora sojae in Xinjiang, the results showed that all strains growed at 10-35℃,the optimum growth temperature was 25℃and pH was 7.0. Mycelial growed quickly and produced plenty of oospores at carrot,soybean juice and V8 media .Using method combined the routine with molecular detection proved Phtophthora sojae in Xinjiang accorded with domestic and overseas. This results showed Phytophthora root rot has happened ,but occurred only original phase in xinjiang . Identification of race of Phytophthora sojae indicated virulence formula were classified into four virulence types which were obviously different from 53 races reported in domestic and overseas, respectively. It was estimated that Phytophthora sojae in xinjiang are possible new.The resistance test indicated that the most of breeds were sensitive to phys1, 864 belonged to high resistance and MN1801 have resistance. It is resistant to phys2,phyq1 ,phy143 and Yidadou1#,MN1801,P54-89,864 were high resistant.Through the winter test showed Phtophthora sojae can not live with Mycelial but the oospores, the oospores are sources for infecting the next year.This experiment also found that the new Phtophthora which is global Oogonium and spermary hypogynous,but its mycelial growth was faster than Phytophthora sojae and didn't Sporange. By the molecule biology experiment, sequencing results indicated that homology is 99% with P.medicaginis×cryptogae, the strain require studying further. The results of medicaments screening indoor showed that metalaxyl,Mancozeb,cymoxanil+mancozeb and thiram+ziram have better restrain effect to Phytophthora soja and Pythium aphanidermatum. Identification of Pythium indicated is mainly Pythium aphanidermatum,the result was different from Wangchunhua's Pythium ultimum, possible the samples were collected from different places.