Abstract: 【Aim】Bemisia tabaci is a species complex with rapid evolutionary modifications. In recent years, its biotypes gained more attention because of its increasing hazards to the agricultural crops. Previously there were few sympatric non-B biotypes in different regions of China except B biotype. The study described herein provides some theoretical basis for its biotype detection and integrated control by identifying its biotypes which currently prevail in China and their relationship with different biotypes from other countries.【Methods】The biotypes and phylogenetic relationships of 22 different non-B biotype populations collected from six provinces were studied based on 16S rDNA sequences. 【Results】 The results revealed that the 22 different populations of non-B B. tabaci belong to Q, Nauru and An biotypes. Evolutionary divergence among these biotypes was more than 10%. The relationship between Q and B biotypes was closest, with genetic distances between 2.8% and 4.0%. The genetic distances among different biotypes were significantly higher than within the same biotype, while Q biotype showed the least genetic distance of 0.9% within itself. It is a universal phenomenon that multiple biotypes prevail in the same region. The Nauru biotype was more widely distributed than the other two biotypes. The highest variety of non-B biotypes was detected in Yunnan province. 【Conclusion】 The genetic differentiation of B. tabaci is very complicated. The biotypes of B. tabaci can be effectively identified using 16S rDNA gene.

Key words: Bemisia tabaci, biotype, 16S rDNA, genetic distance, phylogenesis