Molecular Identification, Incidence, and Distribution of Acidovorax avenae in the Sugarcane-Producing Agroecological Regions of Mexico

Acidovorax avenae causes red stripe disease, which is characterised by red stripe and top rot symptoms in sugarcane ( Saccharum spp. hybrids). The incidence of one or both these symptoms in the sugarcane fields was up to 30% in the Chiapas and Veracruz states of Mexico between 2015 and 2016. This study aimed to identify the causative agent of these symptoms and to determine the distribution and incidence of the disease in sugarcane-producing agroecological regions. Eleven bacterial isolates with phenotypic characteristics similar to those of A. avenae were isolated from the symptomatic tissue. Phylogenetic reconstruction based on the 16S rDNA sequence identified these 11 isolates as A. avenae with 99% identity. A. avenae infection was identified in three of the seven agroecological regions of Mexico (Cordoba-Gulf, Papaloapan-Gulf, and Southern region) with incidences ranging between 1 and 55% . The highest incidence of A. avenae infection was in the COLMEX 94-8 variety in the Cordoba-Gulf region (55%), whereas the lowest (1%) incidence was in the CP 72-2086 variety in the Papaloapan-Gulf region. The inoculation of these 11 strains resulted in the development of necrosis and wilting of the youngest leaves, dead of inoculated leave, and stem rot symptoms in the susceptible variety CP 72-2086. This is the first study to report the distribution and incidence of A. avenae in sugarcane plantations of Mexico.