Author
PUTTAMUK, THAMRONGJET - Kasetsart University | |
ZHANG, SHOUAN - University Of Florida | |
Duan, Ping | |
JANTSON, AROM - Kasetsart University | |
THAVEECHAI, NIPHONE - Kasetsart University |
Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/22/2014 Publication Date: 7/26/2014 Citation: Puttamuk, T., Zhang, S., Duan, Y., Jantson, A., Thaveechai, N. 2014. Effect of chemical compounds on the ‘Cadidatus Liberibacter asiaticus’ infected pomelo (Citrus maxima). Crop Protection Journal. 65:(2014)114-121. Interpretive Summary: Citrus huanglongbing (HLB) is a devastating bacterial disease of citrus worldwide. In Thailand, HLB is caused by the bacterium ‘Candidatus Liberibacter asiaticus’ (Las). Currently, there is no adequate cure for this disease and infected trees will decline in productivity and health over time until they die. In this article, combinations of antibiotics were evaluated for their ability to kill Las in infected pomelo citrus plants via injection. Results show that a mixture of streptomycin, ampicillin, penicillin G, and Bacicure® provided the highest efficiency in eliminating or suppressing the Las-bacterium population in Las-infected plants both in greenhouse experiments and field trials. It is worth noting that this chemical treatment remained therapeutically effective for at least one year. Technical Abstract: Huanglongbing (HLB), also known as citrus greening, is one of the most destructive diseases affecting Rutaceae plants in many parts of the world. HLB is associated with three species of ‘Candidatus Liberibacter’ with ‘Ca. L. asiaticus’ (Las), being the most widely distributed in Thailand and Asia. The effectiveness of chemical control for HLB disease was evaluated in Las-infected pomelo (Citrus maxima) tree using trunk injection method. Our results demonstrated that a mixture of streptomycin (25 mg/L), amplicillin (2.5 g/L), penicillin G (2 g/L), and Bacicure® (2 g/L) provided the highest efficiency in reducing and suppressing the Las-bacterium population with the Ct mean value from 20.8 (˜ 7.2 × 107 cells/g of plant tissue) to 36.6 (˜ 2,140 cells/g of plant tissue) in greenhouse experiments, and the Ct mean value from 19.4 (˜ 1.8 × 108 cells/g of plant tissue) to 37.8 (˜ 969 cells/g of plant tissue) in the field experiments. In addition, our strategies remained therapeutically effective for one year. Finally, response of Las-infected pomelo toward chemical treatments was elucidated using transmission electron microscopy. |