Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

Abstract

Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August), the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%). To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

Mechanistic insights into host adaptation, virulence and epidemiology of the phytopathogenXanthomonas

“…This antibiotic treatment is effective for disease control in peach and no resistance to the treatment has been reported. The quinolone antibiotic oxolinic acid was reported to be successful in initial field trials against X. frageria and other bacterial pathogens such as Erwinia amylovora and Burkholderia glumae (Kim et al 2016). However, this treatment failed to sustain its effect in long-term application because of the occurrence of resistant E. amylovora and B. glumae strains (Stockwell and Duffy 2012).…”

Biological control of bacterial plant diseases with Lactobacillus plantarum strains selected for their broad‐spectrum activity

“…actinidiae (Psa), the bacterial spot of stone fruits caused by Xanthomonas arboricola pv. pruni (Xap) and the angular leaf spot of strawberry caused by Xanthomonas fragariae (Xf) (Donati et al, ; Kim et al, ; Lamichhane, ). The European and Mediterranean Plant Protection Organization (EPPO) lists Psa, Xap and Xf as quarantine organisms.…”

Genome-based population structure analysis of the strawberry plant pathogen Xanthomonas fragariae reveals two distinct groups that evolved independently before its species description

“…Angular leaf spots (ALS) on strawberry plants are caused by the Gram-negative gammaproteobacterium Xanthomonas fragariae [ 27 ] that is categorized as a quarantine organism by the European and Mediterranean Plant Protection Organization [ 28 ]. The bacterium has been reported to be the major bacterial disease affecting cultivated strawberry ( Fragaria × ananassa Duchesne) [ 29 ], and has become increasingly problematic in agricultural strawberry production [ 30 ]. The disease was first described in 1960 in Minnesota, USA [ 27 ] and then formally reported in most major strawberry-producing regions worldwide [ 31, 32 ].…”