Identification of natural isolates of Xanthomonas albilineans from Tucumán, Argentina.

MIELNICHUK N; BERTANI R; JOYA C; FUNES C; HENRIQUEZ DD ; PERERA MF; GONZÁLEZ V; CUENYA MI; CASTAGNARO AP; VOJNOV AA

Encuentro; XanthoMeeting 2015; 2015

Xanthomonas alblilineans is the causal agent of sugarcane leaf scald, one of the most important diseases affecting sugarcane crop in Argentina. This pathogen has particular characteristics such as its reduced genome and the lack of one of the major pathogenicity determinants of the group: the xanthan gum cluster (Pieretti et al., 2012). In this work, natural bacterial isolates were obtained from different varieties of sugarcane plants showing leaf scald symptoms, some of which were preliminary analyzed by dot blot assays. Sampling was done from six locations in Tucumán. A total of 27 isolates were analyzed by PCR using specific primers for X. albilinenas detection (Pan et al., 1997). Furthermore, when 16S rRNA sequencing was done for five positive isolates identified by PCR, only three were determined as X. albilinenas while the other two as Xanthomonas sacchari. The identification of the rest of the isolates by 16S rRNA sequencing it is also shown here. Other characteristics such as colony aspect, nutrient requirement and xanthan production of some strains were also analyzed. This is the first time that the identity of several isolated bacteria from sugarcane with leaf scald symptoms from different regions of Tucumán is determined. Future studies will allow us to establish a relationship between isolates and disease severity.