1Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj-211007, Uttar Pradesh, India
2Division of Plant Pathology, Indian Agricultural Research Institute, Pusa Campus, New Delhi-110012, India
3Department of Biochemistry and Biochemical Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj-211007, Uttar Pradesh, India
*Corresponding author e-mail: Surabhi Mitra (surabhimitra19@gmail.com)
Online published on 5 March, 2025.
A study was conducted in Delhi to identify mixed infections in important citrus cultivars using PCR and RT-PCR assays using specific primers for phytoplasmas, ‘Candidatus Liberibacter’ species (HLB), and citrus tristeza virus (CTV) to test pomelo, kinnow mandarin, and kagzi kalan lemon cultivars from different fields. Citrus samples from symptomatic leaf tissues were examined and 16S rRNA, omp, and coat protein (CTV) genes verified by sequence comparisons, confirmed the presence of mixed infection with amplification of the expected length fragments of about 1.25 kb, 809 bp and 672 bp, respectively. Additionally, the investigation verified that 16SrI-B subgroup phytoplasmas were present in pomelo, while 16SrII-C subgroup was detected in kinnow mandarin and 16SrII-D subgroup in kagzi kalan lemon. These results were confirmed using virtual restriction fragment length polymorphism. The presence of ‘Ca. L. asiaticus’ identified by phylogenetic analysis was detected in all tested samples. Genetic diversity was also discovered in the CTV isolates that were separated into three genogroups based on the coat protein gene.
Citrus greening, HLB, CTV molecular detection, Phylogenetic analysis
