TY - BOOK AU - Mohapatra, Anwesha AU - Meetei, Ng. Tombisana TI - Molecular detection of Huanglongbing bacterium “Candidatus Liberibacter asiaticus” associated with Khasi Mandarin PY - 2024/// CY - Umiam PB - CPGSAS, CAU(Imphal) KW - Khasi Mandarin KW - Diseases KW - Huanglongbing bacterium N1 - Includes bibliographical references N2 - The Khasi mandarin holds significant economic importance among citrus crops in northeastern regions, contributing substantially to the area's socio-economic development. However, citrus decline poses a major challenge in this region, with Citrus Greening disease(CGD) and Citrus Tristeza Virus (CTV) being primary biotic factors in this decline. Huanglongbing (HLB), a particularly severe citrus disease, causes global economic losses. Early detection of the disease would be helpful in preventing the spread of the disease. Thus, the goal of the current study is to analyze the molecular identification of the Huanglongbing bacterium related to Meghalaya's Khasi Mandarin. For this study, eighty Khasi mandarin samples were collected based on characteristic visual symptoms for citrus greening from eight locations of three districts of Meghalaya. The presence of Huanglongbing (HLB) disease was detected through PCR using HLB specific primers of the bacterium and percentage disease index (PDI) was calculated for each location. Among the six primers tested, Primer C demonstrated the highest efficacy in identifying HLB. Out of the 80 samples that were taken, 19 were verified to be positive. The highest percentage disease index was observed from Wahijier, West Jaintia Hills with an overall percentage disease index of 80% followed by 40% in Umsohme, Ri-Bhoi, 30% in Umdenlang, Ri-Bhoi, 20% in Mawphu, East Khasi Hills and lowest with 10% in Nongjrong and Nartiang. In the study, correlation between age and PDI was observed where plants between the age of 15- 20 years were found to be mostly susceptible to infection than the older plants (>20 years). After sequencing, through multiple and pairwise alignment it was observed that the isolates of North eastern regions reported earlier have more alignments with the six isolates of Meghalaya under study. Phylogenetic analysis done by MEGA11 shows the the CGD isolates sequence similarity and evolutionary divergence analysis revealed that they shared more sequence similarities with "Ca. L. asiaticus" isolates (Asian) from the Southeast Asian region than with the varying, uncommon Indian isolates found in the remaining regions of the nation. Thus, identifying distinct HLB isolates enables targeted, effective management strategies, potentially improving disease control and preserving Khasi Mandarin cultivation in Meghalaya UR - https://krishikosh.egranth.ac.in/handle/1/5810220899 ER -