|BUSHE, BRIAN - University Of Hawaii|
|HELLER, WADE - University Of Hawaii|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2017
Publication Date: 3/21/2017
Citation: Sugiyama, L.S., Bushe, B.C., Heller, W.P., Keith, L.M. 2017. First Report of Paraburkholderia andropogonis Causing Bacterial Leaf Streak of Strelitzia reginae in Hawaii. Plant Disease. 101(6):1030.
Interpretive Summary: Bird-of-paradise is a commonly grown ornamental in Hawaii. In March 2014, a nursery located in Panaewa on the eastern side of Hawaii Island noticed that a few liners of Bird-of-Paradise that were imported from Florida had water soaked lesions. Within a month after transplanting the liners into one gallon pots the plants had chlorotic water-soaked lesions that became necrotic. The bacteria causing the disease was identified and its pathogenicity was proven. This is the first report of bacterial leaf streak caused by Paraburkholderia andropogonis on Bird-of-Paradise in Hawaii.
Technical Abstract: Bird-of-Paradise (Strelitzia reginae Banks) is a commonly grown ornamental in Hawaii. In March 2014, a nursery located in Panaewa on the eastern side of Hawaii Island noticed that a few liners of Bird-of-Paradise that were imported from Florida had water soaked lesions. By April 2014 a majority of the liners which had been transplanted into one gallon pots had chlorotic water-soaked lesions that became necrotic. Plant samples were submitted to the University of Hawaii Agricultural Diagnostic Center located at the Komohana Agricultural Research Center in Hilo, Hawaii for diagnosis. Bacteria were consistently isolated from diseased tissue. To differentiate the genera based on growth characteristics, bacteria were plated on NDA, YDC, KMB, CVP and MS agar (2). The consistently isolated bacterium tested negative for Ralstonia solanacearum using an Elisa ImmunoStrip assay and gave a positive reaction for tobacco hypersensitivity (2). Culture plates were forwarded to the USDA-ARS-DKI-PBARC facility in Hilo, Hawaii for further purification and molecular identification. A partial 16S rRNA gene sequence (1,424 bp) (Accession No. KX812539) was 100% identical to multiple accessions of Paraburkholderia andropogonis (basonym, Burkholderia andropogonis) in the NCBI (National Center for Biotechnology Information) database. In May 2014, additional samples exhibiting mild to severe symptoms also yielded P. andropogonis. To confirm pathogenicity, four healthy plants were inoculated with a bacterial suspension from 3 day old cultures grown on LB at 27°C in the dark and adjusted to 10e8 CFU/ml. The pseudostem of each plant was wounded using an 18G needle and injected with 200 µl of suspension. Four control plants were inoculated with sterile distilled water. Plants were placed on greenhouse benches and observed for disease development. After 4 weeks, small black, water-soaked, elongated vein-delimited lesions developed. After 10 weeks numerous elongated lesions identical to the original samples were apparent with a majority of them coalescing into a large lesion with a chlorotic light green-yellow to yellow to orange-yellow chlorotic halo. Bacterial colonies were consistently re-isolated from the inoculated plants and identified as P. andropogonis, while no bacterial colonies were isolated from the control plants, thus fulfilling Koch’s Postulates. The test was repeated twice. To our knowledge, this is the first report of bacterial leaf streak caused by Paraburkholderia andropogonis on Strelitizia reginae in Hawaii. As recommended by Miller (1) diseased leaves from sample plants were rouged. After one year only 25% of the plants still showed symptoms. The results from this study indicate that with early recognition and rouging of diseased leaves it is possible control the recurrence of this disease.