Citrus yellow vein clearing virus transmission by the black citrus aphid, Toxoptera aurantii

Abstract

Citrus yellow vein clearing virus (CYVCV) is a causal agent of yellow vein clearing disease that was first occurred in 1988 on lemon (Citrus limon) and sour orange (C. aurantium). Now CYVCV is widely distributed in the citrus orchards of Iran and reduces the yield and fruit quality of lemons. This virus can be transmitted by insects, grafting and mechanical ways. Citrus aphids including Aphis spiraecola, A. gossypii and, A. craccivora were already reported as vectors of the virus. In the present study, the transmission of CYVCV was investigated by the black citrus aphid, Toxoptera aurantii Boyer de Fonsc. (Hemiptera: Aphididae). T. aurantii were allowed to feed on infected Persian lime (C. latifolia) as donor plant with a 24h and uncertain acquisition access period (AAP). Then 20 adult aphids were transferred on each virus-free Eureka lemon seedlings as receptor plant with a 24 and 48 h inoculation access period (IAP). The results showed that, 3 months post-inoculation, the mean transmission rate of CYVCV by T. aurantii was 26.66% and 33.33% for 24h AAP/24h IAP and 24h AAP/48h IAP, respectively. 6 months later, the mean transmission rate was 26.66% and 36.66% for 24h AAP/24h IAP and 24h AAP/48h IAP, respectively. There was a significant difference in transmission rate between the two acquisition and inoculation access periods but did not differ between the 3 and 6 months after inoculation significantly. The present work confirmed that the virus is transmitted from citrus to citrus by T. aurantii in the greenhouse under controlled conditions.