Grapevine leafroll associated virus-3 in Sichuan, China.

摘要

DAS [double antibody sandwich]-ELISA, RT-PCR [reverse transcriptase-PCR] and electron microscopy were used to detect Grapevine leafroll-associated virus 3, GLRaV-3, in 22 shoot samples from various grape cultivars in Sichuan, China. RT-PCR and electron microscopy were more sensitive to the virus than DAS-ELISA. The analysis of the phylogenetic tree relative to the coat protein revealed that the Sichuan isolate clustered together with other Chinese isolates. The coat protein was calculated to be approximately 34.8 kD. The analysis of the amino acid alignment in the Sichuan isolate showed that lysine, valine and threonine in 3 different positions were substituted with arginine, alanine and alanine, respectively. A total of 183 samples from 4 locations in Sichuan (Logng-Quan, Shuang-Liu, Peng-Shan and Pan-Zhihua) were analysed by DAS-ELISA for the presence of GLRaV-3. The results indicated that the average infection rate was around 39.9%, and the highest disease incidence occurred in Peng-Shan. The analysis of samples from Peng-Shan revealed that all the clones of Seedless Zaohong, Seedless Jingxing, Yatomi Rosa and Benni Fuji were completely infected, whereas those of Jingya and Kyoho were not infected.