Variation in the transmission of barley yellow dwarf virus-PAV by different Sitobion avenae clones in China

- We tested for Chinese aphids' ability to transmit BYDV-PAV- Belgium/CN isolate.
- We found Sitobion avenae has no specificity in BYDV-PAV isolates.
- All Chinese S. avenae populations could transmit BYDV-PAV-Belgium isolate.
- Population with highest transmission efficiency was from high BYDV prevalent area.
- The most transmission efficiency of population from northern (ST) China regions.

Fourteen Sitobion avenae Fabricius (Hemiptera: Aphididae) clonal lines (clones) originating from China were tested for their ability to transmit BYDV-PAV (one isolate from Belgium and another from China) using wheat plants. By sequence analysis, the coat protein gene of BYDV-PAV-BE was distinguishable from BYDV-PAV-CN. All of the clones could transmit BYDV-PAV, and the transmission varied from 24.42% to 66.67% with BYDV-PAV-BE and from 23.55% to 56.18% with BYDV-PAV-CN. These data suggest that S. avenae has no specialty in BYDV-PAV isolate. Significant differences in the transmission frequencies between the clones with BYDV-PAV-BE and BYDV-PAV-CN were observed. The transmission efficiencies of aphid clones from the middle-lower reaches of Yangtze River (AH, HD, HDE, HZ, JZ, JY and SJ) and Yunnan province (YH) were similar. Nevertheless, differences in the virus transmission efficiencies of the clones from northern (ST and STA) and northwestern (QX, SB and XS) regions were assessed. The transmission efficiency of S. avenae from northern and northwestern China, where BYDV impact is more important, was higher than that from the middle-lower reaches of the Yangtze River and Yunnan province. This work emphasizes the importance of considering aphid vector clonal diversity in addition to virus strain variability when assessing BYDV transmission efficiency.