First report of Acidovorax citrulli causing a leaf spot disease on tomato plants in Greece
- PDF / 143,284 Bytes
- 1 Pages / 595.276 x 790.866 pts Page_size
- 38 Downloads / 232 Views
DISEASE NOTE
First report of Acidovorax citrulli causing a leaf spot disease on tomato plants in Greece Dimitris Malliarakis 1 & Evaggelia Mpalantinaki 1 & Marianthi G. Pagoulatou 1 & Konstantina Lorenzou 1 & Dimitrios E. Goumas 1 Received: 2 September 2020 / Accepted: 6 October 2020 # Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2020
Keywords Tomato . Acidovorax citrulli . Detection . Greece . Europe
Necrotic black spots, often with chlorotic haloes, were observed on leaves of tomato seedlings growing in two transplant houses in Greece, during June 2019 and April 2020. Approximately 20 to 30% of the seedling plants were diseased, causing serious economic losses to the houses. Isolations from the infected leaf tissues on King’s B medium consistently yielded a slow-growing and nonfluorescent bacterium, forming cream-coloured colonies. Recently, these isolates were characterized as Acidovorax citrulli (Ac) with the following methodologies. They were found to be gram-negative,aerobic, oxidase-positiveand negativefor arginine, aesculin, gelatin and levan tests. They also induced hypersensitive response on tobacco and reacted with specific antiserum for Ac (Cat. No. 07354/02, Loewe®). Additionally, the isolates were identified by PCR amplification with specific primers SEQ ID no.3/ no.4 (Schaad et al. 2000). Blast analysis of 16S rDNA sequence of the specific isolate HMU50556 (424 bp, GenBank Accession No. MT906357) showed 99.53% similarity to Ac type strain ICMP7500 = ATCC29625 (NR_041758.1), strain T1 (WSBA01000009.1) and AAC00-1 (NZ_RCCQ01000001.1). Furthermore, the gyrB partial sequence (879 bp, MT912472) was 99.54% identical to Ac type strain ICMP7500 (GU385478.1) and 100% identical to strains T1 (NZ_WSBA01000009.1) and AAC00-1 (NC_008752.1). Pathogenicity tests were conducted on tomato and watermelon seedlings by spray-inoculation with suspension of the isolate HMU50556 (108 CFU mL− 1). Also, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s42161-020-00677-1) contains supplementary material, which is available to authorized users. * Dimitris Malliarakis [email protected] 1
Laboratory of Biological and Biotechnological Applications (Plant Bacteriology), Department of Agriculture, School of Agricultural Sciences, Hellenic Mediterranean University (HMU), Heraklion Crete 71004, Greece
mature watermelon fruits were inoculated using toothpick technique. Symptoms were developed within 7 days and resembled thoseofnaturalinfections.Thebacterium wasthenre-isolatedfrom infested tissues of all seedlings and identified as Ac, fulfilling Koch’s postulates. To our knowledge, this is the first report of Ac causingdiseaseontomato seedlingsinGreece,Europe,confirming previous findings in Israel (Chalupowicz et al. 2020) that this species can infect other plants than cucurbits. Our observations indicate possible transmission and spread of Ac through tomato seeds. Acknowledgements This research has been co-financed by the European Union and Greek national funds through the Operation
Data Loading...
