Silicon amendment to rice plants reduces the transmission of southern rice black-streaked dwarf virus by Sogatella furcifera

BACKGROUND Plant viruses are transmitted mainly by piercing-sucking herbivores, and viral disease management relies on chemical control of vectors. Southern rice black-streaked dwarf virus (SRBSDV) is transmitted by the white-backed planthopper (WBPH), Sogatella furcifera. This study aimed to evaluate the potential of silicon (Si) amendment for reducing SRBSDV transmission. RESULTS The settling and ovipositional preferences of WBPH females decreased significantly by 14.6-43.7% for plants treated with either 0.16 g or 0.32 g SiO2 kg(-1) soil during SRBSDV acquisition and by 26.2-28.3% for plants treated with 0.32 g SiO2 kg(-1) soil during SRBSDV inoculation, compared with controls. Adding either 0.16 or 0.32 g SiO2 kg(-1) soil significantly reduced SRBSDV inoculation rate by 31.3% and 45.3%, respectively, and acquisition rate by 25.5% and 66.0%, respectively. Silicification was intensified more in plants treated with 0.32 g SiO2 kg(-1) soil than in controls. The nonprobing (np) duration increased, and the phloem sap ingestion (N4-b) duration decreased significantly in the WBPHs feeding on high-rate-Si-supplemented plants compared with control plants during both inoculation and acquisition access. CONCLUSION This study showed that Si amendment to rice plants decreased the WBPH settling and ovipositional preference and the SRBSDV acquisition and inoculation rates, thereby reducing SRBSDV transmission. The intensified plant silicification and the altered WBPH feeding behaviors (i.e. prolonged np and shortened N4-b) may explain the reduced SRBSDV transmission in Si-amended plants.