Abstract: Morphological identification of whitefly is limited by small size, the high degree of similarity and polymorphism. In this study, the method for the development of DNA markers for rapid detection of the spiny whitefly, Aleurocanthus spiniferus (Quaintance), was developed based on sequence characterized amplified region (SCAR) derived from a randomly amplified polymorphic DNA (RAPD) band. An approximately 990 bp DNA fragment of A. spiniferus, which is absent in other closely related whitefly species [e.g., Dialeurodes citri (Ashmead), Bemisia tabaci (Gennadius) (biotypes B, Q, ZHJ-1 and ZHJ-2), Trialeurodes vaporariorum (Westwood) and Aleurodicus disperses (Russell)］, was identified by RAPD-PCR analysis. After cloning and sequencing the target fragment (987 bp, GenBank accession no.: FJ613323), one pair of SCAR primers (AS-F518/AS-R938) was developed, which could amplify a single fragment of 421 bp in length. Specificity tests performed with this pair of primers showed that all A. spiniferus specimens were detectable and no cross reactions with other whitefly species were observed. The method was tested on egg (3 eggs as one sample), single 2nd and 4th instar nymph, and male and female adults, and proved to be applicable for these stages of A. spiniferus. Moreover, the 421 bp DNA fragment could be clearly identified even at the dilution as low as 1/1 920 of a whole female adult of A. spiniferus for all replicates. This technique should be useful in quarantine and detection of A. spiniferus during transportation of the seedlings of tea and orange.

Key words: Aleurocanthus spiniferus, RAPD, SCAR, rapid identification, specific amplification