1. WAJEEHA BATOOL CHAUDHARY - Department of Biotechnology, Lahore College for Women University Lahore, Pakistan.
2. RUKHAMA HAQ AND SHAGUFTA NAZ - Department of Biotechnology, Lahore College for Women University Lahore, Pakistan.
Huanglongbing (HLB), also known as citrus greening disease, caused by the bacterium Candidatus Liberibacter spp (CLas) is one of the most devastating diseases affecting citrus plants worldwide. CLas is a well-studied bacterium, but the role of microbiome’s in HLB development and progression remains unexplored in Pakistani citrus orchards. This study aimed to investigate and profile the microbiomes associated with HLB escape in Pakistani citrus rhizosphere. Ten different bacterial strains were isolated from HLB free rhizosphere by biochemical screening. Bacterial isolates belonged to the class of Firmicutes and Proteobacteria (gamma Proteobacteria) including Pseudomonas, Enterobacter, Proteus, Citrobacter and Serratia. Analysis of the bacterial diversity abundance revealed that Pseudomonas (82%), Bacillus (75%) and Serratia (69%) were the most abundant bacteria in citrus rhizosphere. The isolated strains were studied for plant growth promoting activities including indole acetic acid (IAA) production, sidophore production, and phosphate solubilization. On the basis of these PGP activities the isolated strains showed positive results highest activities were shown by Bacillus safensis, Bacillus subtilis Pseudomonas putida, Serratia plymutica. Our findings reveal that all these PGPR bacteria are beneficial help to reduce the population of viable Ca. L. asiaticus in HLB diseased tree if used as a biofertilizer. This research work provides a foundation for understanding the interaction between the PGPR and Huanglongbing (HLB) in citrus in Pakistan, paving the way for novel disease management strategies and also improving citrus production in the region.
Citrus, Huanglongbing (HLB), Rhizobacteria, PGPRs, Diseaese.