Studies On Host Range,16SrDNA Identification Of Bacterial Spot Of Muskmelon Leaves And PCR Detection Of Bacterial Blotch Of Watermelon

Bacterial spot of muskmelon leaves(Pseudomonas syringae), widely dispersed in Xinjiang was a harmful disease, which brought about enormous economic losing to peasants. Based on investigation in Hexi, Gansu province from 2004 and 2005, it was found that the disease can be observed accasionally on watermelon and muskmelon,and it was likely to be Bacterial blotch of watermelon because of the symptom of the disease on leaves were similar to Bacterial blotch of watermelon,so pathogenic bacteria were isolated and purified from disease leaves for further study in 2004 and 2005.Molecular biology 16SrDNA was used to identify pathogen and Pathonenicity and host range were also examined in this paper. In addition , PCR test was also used to examine whether illness melon and seeds carried Acidovorax avenae subsp.citrulli or not .The results were as following:1 Test of pathonenicity and host range of Bacterial Spot of Muskmelon LeavesTwo typical pathogenic strains Ps1,Ps2 were selected from Seventeen bacterial strains isolated from watermelon and muskmelon in Hexi ,Gansu provice and Aletai in Xinjiang, for Pathogenicity test and host range with standard strain of Bacterial blotch of watermelon in contrast. The results showed that the bacteria and the standard strain of Bacterial blotch of watermelon had the same host range,all of them not only infected with watermelon,cucumber,muskmelon,pumpkin,balsam pear,wax-gourd,calabash gourd,vegetable sponge,etc gourd plants,but also tomato,corn,eggplant,pepper,bean.2 16SrDNA Identification of Pathogen of Bacterial Spot of Muskmelon LeavesDNA of pathogenic bacteria Ps1,Ps2 and standard strain of Bacterial blotch of watermelon were extracted for PCR amplification and sequencing. By comparing these sequences with known sequences in GenBank,it was found that the gene...