Phylogenic Analysis Of Henan Populations And Feeding Behavior Comparison Of Bemisia Tabaci B And Q Biotypes

Bemisia tabaci is one of the most important crop pests in the world. It has developed into many biotypes, among which B and Q are two biotypes causing great losses of crop yield with wide distribution and difficulty in controlling them. It is of theoretical and practical significance to study this pest's damaging causes, their relationship with host plants, genetic backgrounds, for laying basis for effective management measures.In this study, recordings of probing and feeding behaviors of the Bemisia tabaci B and Q biotypes on tobacco and biotype identifications and phylogenic analysis of overwintering populations in Henan Province, were conducted in order to provide some evidences for effective pest controlling strategies, such as resistant crop breeding, inter-cropping and so on. The The results are shown as follows:(1) In this study, the mitochondria cytochrome oxidase I (mtDNA COI) gene of B. tabaci was used to identify the biotypes of 5 representatively geographical locations in Henan province, China. Furthermore, the phylogenic relationships with other differently geographical biotypes of B. tabaci were deduced. Results showed that 2 biotypes of B. tabaci were found in Zhengzhou overwintering fields with B biotype on calla lily (Zantedeschia aethiopica) and Q biotype on tomato. While the biotypes of B. tabaci in Anyang, Xinxiang, Sanmenxia and Xinyang were Q biotype with an identical nucleotide sequence of COI. Results of phylogenic analysis showed the variances of COI between Zhengzhou B and other populations of B biotypes from different locations were not significant. Q biotypes COI sequences of Anyang, Xinxiang, Sanmenxia and Xinyang were clustered in the same branch with Florida Q2 (FJ188524) in phylogenic tree, while sequence of Zhengzhou-2 were clustered to one branch lonely with a phylogenic location between Florida Q1(FJ188559)and Florida Q3 (FJ188570). Results above suggested that the original invasion locations of Q biotypes of B. tabaci were different among populations from Zhengzhou and other districts of Henan Province. (2) Probing and feeding behaviors of Bemisia tabaci B and Q biotypes on tobacco plants were recorded respectively using electrical penetration graph (EPG) technique. The results showed that there were no obvious difference in waveform types between B and Q biotypes , but among 35 variables selected, there were significant differences (at 1% level) in 16 variables and differences (at 5% level) in 3 variables. In comparison, B biotype had more probing and Q biotype had more number of pd and more duration of E waveform. This shows that Q biotype had higher host adaptability than B biotype. This results led light for EPG used as a new identification method of Bemisia tabaci biotypes.