MOLECULAR CHARACTERIZATION OF ASIAN CITRUS PSYLLID (DIAPHORINA CITRI) USING MITOCHONDRIAL CYTOCHROME OXIDASE 1 (MTCO1) GENE

Citrus greening caused by (Candidatus liberibacter spp.) is one of the most destructive bacterial disease of citrus all over the world and it is transmitted by grafting as well as psyllid (Diaphorina citri) is responsible for its spread. This study was aimed to detect the prevalence of CLas in different varieties of citrus in Pakistan and molecular characterization of mtco1 gene in Diaphorina citri. DNA was extracted from fourteen different citrus cultivars infected with citrus greening from different orchards of Sargodha Punjab, Pakistan. Specific primers were used to amplify (Mtco1 gene) in Diaphorina citri and also Las specific primers were also used to detect HLB pathogen. Amplified fragments of 507bp, 1500bp and 2500bp were observed in CLas and Mtco1 gene of Asian isolates. The resulted fragments were TA cloned and sequenced from both strands. The infectious bacterium was found in 3 samples out of 14 (21.5 %) while from psyllid it was found in 5 samples (37.5%). The weather changes effect the prevalence of CLas in citrus but usually it decrease during autumn and found Las positive vector in spring or summer season up to 42oC. So there is a need to research on management of citrus greening disease in Pakistan as it caused major yield loses