Main Types Of Virus Infected Soybean And Smv Resistance On Soybean Under High Temperature

There are many kinds of viruses infecting soybean, but there is little research about soybean virus except Soybean mosaic virus (SMV) in recent years. Soybean specimens collected on the field were tested by ELISA. It is very helpful to understand the main types of viruses and can provide guidance for local production and breeding.Soybean mosaic virus (SMV) is one of the most broadly distributed viral diseases worldwide in soybean cultivars [Glycine max (L.) Merr.]. It caused yield losses and seed quality deficiency seriously. The infected leaves showed latent symptom under a higher temperature environment. In this study, it is aimed to research the changes of SMV virus content, the sequence of CP gene and the defense enzymes in soybean-SMV interactions under high temperature. The main results were given as follows:1.109specimens or isolates from the Huang-Huai region and Heilongjiang province were tested by ELISA of12virus. In the study, three kinds of viruses were found, SMV, WMV and TMV. The number of SMV, WMV and TMV positive samples was26,16andl respectively, representing the total number of samples detected23.85%,14.67%and0.92%. The other9kinds of viruses were not detected. The WMV positive specimens were inoculated on6host plants, the symptom reactions showed the different pathogenicity between different WMV strains.2. To compare the latent period and pathogenicity of SMV under different treatments, Nannong1138-2inoculated with SC7showed weak or latent symptoms, prolonged latent period, reduced disease index under higher temperature. It was suggested that soybean resistance to soybean mosaic virus was enhanced by an appropriate increase in the ambient temperature and at the same time the soybean plants showed latent symptoms.3. Grown under high temperature for five subcultures, there was no gene mutations in CP gene. It was suggested that CP gene mutation did not occur under high temperature in this study. By qRT-PCR and statistical analysis software SPSS18.0to do analysis the virus content and significant differences, the results showed that there was no significant difference (P>0.05) for the same part soybean leaves in different temperature. Under the same temperature, there is higher virus content in soybean second trifoliate leaves than the fourth trifoliate leaves, and there was extremely significant difference (P<0.01) at25℃and35℃.4. To research the changes of enzyme activities of SOD, POD, PPO, PAL, CAT activities under four different conditions. We found that the enzyme activities of POD, PPO, PAL and CAT in the soybean plants inoculated with SMV were higher than with PBS under the same temperature. It showed that SMV stimulated the enzyme activities. But the enzyme activities of POD, PPO and PAL were higher in high temperature than usual temperature after7DAI (days after inoculation) and14DAI. It was suggested that high temperature improved the enzyme activities of POD, PPO and PAL, while the CAT enzyme activity was declined. Results indicated that, high temperature does affect the activities of defense enzymes and the change of enzyme activities might cause the latent symptom and the improving of soybean resistance.