Sequence Characteristics Of Ribosomal Genetic Structure Erwinia Amylovory And Molecular Detection For The Pathogen

Fire blight of pear caused by Erwinia amylovora is one of the most devastating disease of rosaceae plants such as pears and apples, It is also important Chinese quarantine pathogen. The long-distance spread of Erwinia amylovora mainly depend on the transfer of reproductive material and fruit among different areas.Thus, development of the rapid and effective molecular detection assays for this pathogen is not only very important for Chinese trade, but also for the prevention of its spread.In order to prove the material was correct, amplified Erwinia amylovora DNA sequence using bacteria 16S universal primers 16 SF/16SR and had 1489bp producer. Blasting the sequence in GeneBank database, the results indicated that it has 98% similarity with 16S sequence of Erwinia amylovora(AF141895.1). By the use of DNAMan, DNAsist1.0, Primer 5.0 software, the restriction sites, open reading frames and motif structure of 23S, IGS sequence were analyzed, isoelectric point, transmembrane helix and hydrophobic were also predicted after DNA sequence been translated into amino acid sequence using EXPAsY software, then blasted in the PDB database for searching similar amino acid sequence. The results indicated that the amino acid of 23S and IGS were 75% and 33% similar with 2EZU65 and 2GMW66 respectively.Based on 23S and IGS sequences, two pairs of specific primers 23SF/23SR and IGS-S/IGS-R, which had specific 166bp and 154bp producer respectively, were designed. The sensitivity of the primers were 10-6μg/mL, 10-7μg/mL and 23SF/23SR could detect as few as 3.4 x102 cfu/mL when quantified to the number of bacteria. 23SF/23SR could also be used to detect single colony of Erwinia amylovora. Acquisition of 46 Chinese pear quality of nine disease comceptible , 37 disease-resistant; 8 foreign pear quality, 6 flu disease.According to the study of China Erwinia amylovora potential distribution, collected pears from the potential regions and identified their resistance to Erwinia amylovora,. The results indicated that,out of 46 Chinese pear lines , 9 were sensitivity, 37 were Resistance, out of 8 pear lines from foreign, 6 were sensitivity.