The Relationship Between Southern Rice Black-streaked Dwarf Virus And Rice Hormone

Rice (Oryza sativa, L.) is one of the most important food crops in China. It is the key to ensure food safety. However, rice diseases and pests threaten the quantity and quality in rice production, among which southern rice black-streaked dwarf disease caused by southern rice black-streaked dwarf virus (SRBSDV) is destructive.In oder to elucidate the change of hormone level in rice infected by SRBSDV, infected rice plant in the same growth period was obtained by artificial inoculation, and confirmed by RT-PCR, ELISA was used to detect the content of hormone in infected and healthy rice. The results showed that the content of gibberellin, auxin and brassinolide were remarkablly decreased, while the content of abscisic acid was increased significantly. The study definited the change of the endogenous hormone in rice after infection and laid the foundation for studying the pathogenic mechanism of SRBSDV.To elucidate the mitigation effect of exogenous hormone to SRBSDV, infected rice in the tillering stage were sprayed different hormone in the same concentration. Net photosynthetic rate, SPAD value, plant height and MDA level were detected. The results showed that net photosynthetic rate and plant height were significantly improved in infected rice after the spraying, while SPAD value and MDA level were significantly decreased. The mitigation effect of gibberellin is better than other hormone. Therefore, exogenous hormone have the potential of growth pathogen resistance improvement. These results provide new approach to control of SRBSDV.To evaluate the actual effect for gibberellin control southern rice black-streaked dwarf disease, gibberellin at doses of 30、60、90 mg/L were sprayed, the control effect and production were tested. The results showed that the control effect in different treatment for Southern rice black-streaked dwarf disease did not have significant difference, however, gibberellin improved production of rice infected by SRBSDV. This study convinced that gibberellin has mitigation effect to Southern rice black-streaked dwarf disease.