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Injection–Infiltration of Attached Grapefruit with Xanthomonas citri subsp. citri to Evaluate Seasonal Population Dynamics in Citrus Canker Lesions
Author(s) -
Graham James H.,
Gerberich Kayla M.,
Davis Craig L.
Publication year - 2016
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/jph.12478
Subject(s) - xanthomonas citri , citrus canker , citrus paradisi , biology , inoculation , horticulture , population , canker , lesion , veterinary medicine , botany , rutaceae , microbiology and biotechnology , bacteria , medicine , pathogen , genetics , environmental health , psychiatry
To study population dynamics of Xanthomonas citri subsp. citri (Xcc) in citrus canker lesions on fruit, a needle‐free injector was used for infiltration of bacterial inoculum into fruit in situ on mature ‘Ruby Red’ grapefruit ( Citrus paradisi Macf.) trees in Florida. Inoculations of Xcc at 10 5 colony‐forming units (cfu) per ml were conducted in 2012 and 2013 on attached fruit varying from 15 mm to 90 mm in diameter. Inoculations were repeated every 2–3 weeks until the fruit were no longer injectable. On fruit less than 40 mm in size, erumpent lesions formed within 2 weeks of inoculation and expanded 1–9 mm in diameter from 30 to 120 days postinoculation (dpi). Xcc populations in lesions were 6–8 log cfu per lesion at 30 dpi and maintained this population up to 90 dpi. By 120 dpi, Xcc populations declined 1–3 log units as rainfall and temperature decreased in September–October. Xcc populations declined to ~3 log cfu per lesion after 120 dpi in November 2012 and 2013, whereas the population resurged to 5 log cfu per lesion after 180 dpi in January–February 2014.