Symptoms and yield loss caused by rice stripe mosaic virus

BACKGROUND: Rice stripe mosaic virus (RSMV) is a tentative new Cytorhabdovirus species in family Rhabdoviridae transmitted by the leafhopper Recilia dorsalis. Although the virus was first detected in southern China in 2015, few studies have investigated rice symptoms and yield losses caused by RSMV infection. METHODS: In this study, we observed and systematically compared symptoms of three virally infected, representative varieties of indica, hybrid and japonica rice and determined the yield parameters of the artificially inoculated plants. RESULTS: The three RSMV-infected cultivated rice varieties exhibited slight dwarfing, striped mosaicism, stiff, crinkled or even twisted leaves, an increased number of tillers, delayed heading, cluster-shaped shortening of panicles and mostly unfilled grains. Slight differences in symptom occurrence time were observed under different environmental conditions. For example, mosaic symptoms appeared earlier and crinkling symptoms appeared later, with both symptoms later receding in some infected plants. Yield losses due to RSMV also differed among varieties. The most serious yield reduction was experienced by indica rice (cv. Meixiangzhan), followed by hybrid indica rice (cv. Wuyou 1179) and then japonica (cv. Nipponbare). Single panicle weight, seed setting rate and 1000-kernel weight were reduced in the three infected varieties compared with healthy plants—by 85.42, 94.85 and 31.56% in Meixiangzhan; 52.43, 53.06 and 25.65% in Wuyou 1179 and 25.53, 49.32 and 23.86% in Nipponbare, respectively. CONCLUSIONS: Our findings contribute basic data for field investigations, formulation of prevention and control strategies and further study of the pathogenesis of RSMV.