Situation of HLB in citrus production areas of Argentina.

ACOSTA, M.E.; MARTINEZ, V.; FOGLIATA, G.M.; ROJAS, A.A.; PLOPER, L.D.

Foz do Iguacu

Congreso; International Citrus Congress 2016; 2016

IAC - IAPAR

Since 2009, Argentina has a National Huanglongbing Prevention Program coordinated by Senasa (National Health Service and Food Quality of Argentina). EEAOC has the responsibility of monitoring the citrus production areas in Northwest Argentina (NWA) and carrying out diagnostic analyses on plants and insects.. EEAOC also analyzes samples remitted by Senasa from Northeast Argentina (NEA), the other important citrus production region. From the monitoring activities in NWA, nearly 13,000 samples were collected and analyzed by qPCR-TaqMan and Nested-qPCR TaqMan. Samples included citrus leaf and fruit (51%), Murraya paniculata leaf (3%) and Diaphorina citri (46%), the insect vector of the disease. From NEA, EEAOC received 100 samples. Results showed that all NWA samples were negative, whereas 43 citrus samples from NEA were positive (21 detected by qPCR-TaqMan and 22 by Nested-qPCR-TaqMan) (100-104 copies/µl in leaves; 102-104 copies/µl in fruit). The 16S rDNA gene sequence revealed 99.7% similarity with Candidatus Liberibacter asiaticus (Las) (strain: psy62, accession number L22532; MEGA-4, EzTaxon-e identification service). To date there is no evidence that Candidatus Liberibacter spp. is present in Northwest Argentina, but it was detected in the Northeast Argentina, where Senasa conducts a contingency program (eradication of positive trees and intensive monitoring, among other measures). Nested-qPCR-TaqMan used by check negative for doubtful samples was important because it detected Las in samples diagnosed as negative by qPCR-TaqMan.