Abstract: To identify the species of over-wintering whitefly pseudo-pupae and detect the infection status of tomato yellow leaf curl virus (TYLCV) in Bemisia tabaci (Gennadius) in winter greenhouses in Liaoning, northeastern China, 17 samples of whitefly pseudopupae were collected from different counties in the province in January, 2012. The whitefly species was identified under microscope based on morphological characteristics and the biotype of B. tabaci was determined using mitochondrial cytochrome oxidase I (mtCOI) gene. Then TYLCV in the whitefly vector, B. tabaci was checked using specific primers and the product was sequenced and analyzed. The results showed that there were two whitefly species, i.e., Trialeurodes vaporariorum (Westwood) and B. tabaci, over-wintering in winter greenhouses in the province. Of the 17 whitefly samples, 11 were B. tabaci B-biotype samples while the other 6 were mixtures of two whiteflies (biotypes B and Q). In addition, T. vaporariorum was dominated in only one mixture in Linghai, Jinzhou (code LH). Of the 17 B. tabaci samples including the mixtures, only 4 samples were the mixture of biotypes B and Q, while the other 13 were Q-biotype samples. TYLCV was only detected in 3 Q-biotype samples. Phylogenetic analysis also revealed that the virus was TYLCV. These results provide scientific basis for the forecast, prevention and control of the whiteflies and TYLCV in Liaoning, China.

Key words:  Bemisia tabaci biotype Q, Bemisia tabaci biotype B, Trialeurodes vaporariorum, tomato yellow leaf curl virus (TYLCV), greenhouse, Liaoning Province (TYLCV), greenhouse, Liaoning Province