Efficient Inoculation of Rice black-streaked dwarf virus to Maize Using Laodelphax striatellus Fallen.

Maize rough dwarf disease caused by Rice black-streaked dwarf virus (RBSDV) is the most important disease of maize in China. Although deploying disease resistant hybrids would be the most effective way to control the disease, development of resistant hybrids has been limited by virus transmission rates that are too low for effective screening. An efficient inoculation technique for RBSDV was developed using Laodelphax striatellus Fallen, in which a virus-free planthopper colony was developed and viruliferous planthoppers were obtained by allowing a 3- to 4-day acquisition access period on RBSDV-infected wheat plants. Planthoppers were then allowed a 25- to 28-day latent period on wheat seedlings followed by a 3-day inoculation access period on two-to-three-leaf stage maize seedlings. By 35 days postinoculation, susceptible hybrid 'Zhengdan 958', inbred lines of 'Ye 107' and 'Ye 478' plants showed 100% RBSDV infection with symptoms of stunting plants, darkening leaves and white waxy swellings on underside of leaves. At tasseling stage, average disease indices were from 96.4 to 100.0%. Enzyme-linked immunosorbent assays were correlated with the presence of symptoms. The high efficiency of RBSDV transmission obtained using this technique provides a reliable procedure to screen for RBSDV resistance in maize. [ABSTRACT FROM AUTHOR]