Effects of SRBSDV-infected rice plants on the fitness of vector and non-vector rice planthoppers

Abstract

Southern rice black-streaked dwarf virus (SRBSDV) is a new member of the genus Fijivirus and transmitted by whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). The rice area affected by SRBSDV and the subsequent damages are increasing rapidly. In current study, we evaluated the effects of SRBSDV-infected plants on the ecological fitness and the tolerance to adverse environmental factors of vector WBPH and non-vector brown planthopper (BPH), Nilaparvata lugens (Stål). Our study revealed that the fitness of WBPH and BPH were both influenced by feeding on SRBSDV-infected rice. Fecundity of WBPH feeding on the SRBSDV-infected rice plants were higher than those on healthy plants, nymphal duration of male WBPH prolonged markedly by 0.77d (P<0.05), while the weight of brachypterous female adults significantly decreased (P<0.05), and the average survival time shortened both at 26°C and 31°C, respectively. Median lethal time of WBPH on SRBSDV-infected and healthy rice plants were 80h and 112h at 26°C, 64h and 88h at 31°C, respectively. As for non-vector BPH, nymph survival rate decreased significantly by 11.22% (P<0.05) and the longevity of female adults also shortened (P<0.05), while hatchability of BPH eggs increased (P<0.05). Survival time of BPH feeding on healthy rice at 26°C was significant longer than those feeding on healthy and infected rice at 31°C. The above results imply that the vector WBPH suffers much stronger effects than non-vector BPH from feeding on SRBSDV-infected rice plants.