Assessment and molecular characterization of citrus canker causing pathotypes
By: Sumyia Iqbal, Shazia Iftikhar, Anam Rasool
Key Words: Citrus, Citrus Canker, Pathotypes, Molecular characterization, Xanthomonas.
Int. J. Agr. Agri. Res. 8(4), 93-100, April 2016.
Citrus is one of the most popular and significant commercial fruit of Pakistan. Outbreak of Citrus Canker diseased in different varieties causes enormous economic loss. The present research work was conducted to identify and characterize citrus canker causing Pathotypes in citrus varieties from the orchards of Khanpur, district Haripur and Islamabad (National Agriculture Research Council). The survey was conducted in orchards of Khanpur and Islamabad during March, 2015 to find out the incidence, prevalence, severity and disease index as well as for sampling from selected orchards. Varieties encountered during the survey included Grapefruit, Malta (musambi), Red Blood, Ruby Blood and Lemon. Causal organisms were isolated and grown on nutrient agar (NA) and Potato dextrose agar (PDA) for morphological studies. Firstly, Pathogens were identified on the basis of morphological characters.The incidence of Khanpur and National Agriculture Research Council, Islamabad orchards observed were about 10% and 95% respectively. Complete description of macro and microscopic characters was prepared. The purified cultures of bacterial pathogen was then identified and characterized. The identified microbial pathogens include Xanthomonas citri. DNA was successfully extracted and amplified by using TaKaRa Ex taqTM version kit with primers 9F and 15-10R, to confirm the identification by gene sequence. Identified Strains were stored for further study. It is recommended on basis of present study to carry out further experimentation on pathogenicity of these pathotypesforfinding out the citrus varieties resistance against this disease. There is also need to control this pathogen using different biological/chemical agents and genetic engineering techniques.