Abstract

Bacterial canker of kiwifruit (Actinidia chinensis) has become one of the most serious factors that limit the cultivation of kiwifruit in Sichuan, China. Therefore, it is urgent to develop a rapid and precise method to detect the disease at its early infection stage. A 1300 bp specific fragment of pathogenic bacteria was obtained by random amplified polymorphic DNA (RAPD) analysis. This fragment was cloned and sequenced. Based on the sequences of the specific fragment, a pair of specific primers（F7’/R7’）that generated 994 bp single fragment only from the strains of Pseudomonas syringae pv. actinidiae were designed and synthesized. Then, for the detection of diseased kiwifruit trunk tissues collected from orchard and inoculated kiwifruit trunk tissues, the result indicated that the genomic DNA of P. syringae pv. actinidiae can be detected by the specific primers. The sensitivity of the primer set for genomic DNA of P. syringae pv. actinidiae was 100 fg µl-1. Compared with the designed primers with four pairs of published primers. The comparison concluded that only the primers designed in this study was specific to detect bacterial canker of kiwifruit in Sichuan. The result of this experiment showed that the designed and synthesized specific primers F7’/R7’ made it possible to diagnose the kiwifruit canker rapidly and precisely at its early infection stage.

Key words: Bacterial canker, kiwifruit, primer, RAPD, SCAR, P. syringae pv. Actinidiae.