DENSITY OF RHIZOSPHERIC MICROORGANISMS IN MEXICAN LEMON WITH HLB TREATED WITH CHEMICAL INDUCERS

Resumen

Citriculture is a highly profitable activity that is threatened by Huanglongbing (HLB), which is caused by the bacterium Candidatus Liberibacter asiaticus (CLas). The control of this bacterium is fundamental to the management of HLB. The objective of this study was to determine the abundance of total culturable bacteria (B) and filamentous fungi (HF) in the rhizosphere of Mexican lemon (Lm) plants infected with CLas and treated with chemical defense inducers based on commercial molecules (Salicylic acid, Plasmitox®, Blindax®, and Virus-Stop®). A
completely randomized experimental design was used, with six treatments and five replicates: five treatments with CLas (three with commercial inducers, one with salicylic acid, and one without inducer), one without CLas, and one without inducer. The presence of CLas and the severity of HLB were both determined. Five rhizospheric samples were collected every 70 days. Microbial populations were determined by plate count. The presence of CLas was found in LmHLB plants, but no significant decrease (Kruscal-Wallis, p ≤ 0.05) in HLB symptomatology was
detected by the effect of the inducers. However, the population dynamics of total rhizospheric B and HF of Lm were affected by inoculation with CLas (Tukey; p ≤ 0.05), being even lower with the application of the inducers Plasmitox® and Virus-stop®. This response may play an important role in the microbiome associated with the health of Mexican lemon plants.